The Biodiversity in New Guinea
Familiarity will save ecosystems, because bioeconomic and aesthetic values grow as each constituent species is examined in turn: the better an ecosystem is known, the less likely it will be destroyed.
Baba Dioum, a Senegalese ecologist, said: "In the end, we will conserve only what we love, we will love only what we understand, and we will understand only what we are taught."
The beginning of wisdom, as the Chinese say, is calling things by their right names.
(all three quotes from: Edward O. Wilson. The Diversity of Life. Norton NY 1992.)
New Guinea boasts of the world’s largest and smallest parrots, the largest doves, the longest lizard, some of the smallest frogs, the largest butterflies and moths, some of the longest stick insects, the widest-headed (stalk-eyed) flies, the tallest tropical trees, the largest rhododendron flowers, the richest mangrove and sea grass floras, and many other forms and habitats unique and fascinating if not extreme.
J. L. Gressitt (ed.) Biogeography and Ecology of New Guinea.
Section One: Biodiversity of the island of New Guinea pp. 4 - 134
I. Introduction: pp. 4 - 15
II. Basic influences: geology, Ice Ages, landforms: pp. 15 - 20
III. The plant life of New Guinea pp. 20 - 46
IV. Origins of New Guinea’s animals pp. 46 - 49
V. Shrimp and crabs: the crustaceans pp. 49 - 51
VI. Butterflies and beetles: the insects pp. 51 - 60
VII. Fresh water fishes pp. 60 - 64
VIII. Frogs and toads: the amphibians pp. 64 - 74
IX. Lizards, snakes, turtles and crocodiles: the reptiles pp. 74 - 96
X. Class Aves: the birds of New Guinea pp. 96 - 110
XI. Mammals pp. 110 - 134
Section Two: Biodiversity of the Timika area & the Lorentz Park pp. 127-162
I. Introduction pp. 127 - 129
II. Vegetation pp. 129 - 144
III. Insects pp. 144 - 151
IV. Fishes pp. 151 - 152
V. Amphibians and reptiles pp. 152 - 155
VI. Birds pp. 155 - 157
VII. Mammals pp. 157 - 162
Section Three: Natural resource utilization by the Kamoro people pp. 162-203
I. Background pp. 162-165
II. Plant use pp. 165 - 175
III. Animal use pp. 175 - 203 (insects; crustacea; mollusks; fishes; reptiles; birds; mammals)
Appendix I. Glossary pp. 204 - 214
Appendix II. Geological Time Scale 214 - 215
Appendix III. Taxonomy pp. 215 - 223
Appendix IV. Evolution pp. 223 - 226
Appendix V. Species lists: crustacea, amphibia, reptilia pp. 227 - 239
Bibliography pp. 239 - 244
This book was largely written in Timika, Irian Jaya, with only very occasional access to a decent library, due to a lack of time and financial constraints. There is no book covering the biodiversity of the island as a whole, probably because much of the basic research material is difficult to obtain, out of date or nonexistent. Only a few animal groups are well covered in books relatively easy to obtain: birds, mammals, snakes and fresh water fishes. Except for a few very specialized and localized studies, there is nothing on mollusks, most insects (except butterflies and beetles) and very little on lizards. The marine component is woefully neglected, except for Madang Bay and a recent rapid survey of Misool Island. Little attention has been paid to estuarine life. Botany is even in worse shape, at least as far as the interested layman is concerned. As an example, some 90 per cent of the palms species of New Guinea are endemic, but we have to wait until 2005 for a publication on the subject by the Kew Gardens.
On the other hand, the island’s geological odyssey from near Antarctica is well covered in various texts, along with the effects of changing climates and latitudes on the animal and plant life. This also applies to the origins of much of the current life in New Guinea, coming from the Australian continent as well as from south-east Asia. This also applies to the introduction of animals by man, although estimates of the first arrival of dogs and pigs differ sometimes by over 2000 years.
Thus the information available on the biodiversity of New Guinea is very patchy, especially as far as Irian Jaya is concerned. While the Dutch did a very credible job during the early exploratory phases in the pre-World War I phase, this information is now out of date and accessible only in obscure journals. Research on plant and animal life in former German New Guinea is even more difficult. Even trying to obtain recently published material from Papua New Guinea results in plenty of frustration.
The only exceptions to this rather dismal picture lie in a series of publications by the WWF on Irian Jaya mostly focused on conservation and the very recent (starting in 1998) series of rapid ecological surveys by Conservation International which have by now (November 2001) covered four previously unknown areas. Just the first one of these studies found 98 new species, including 34 vertebrates previously unknown to science. Aside from these surveys, the Timika area is the only place that biological research is made easy, if supported by the Freeport Indonesia mining company. This area has produced a wealth of on-going information, which is the reason for the second part of the book being focused there.
The information on the biodiversity of Irian Jaya has been restricted by a lack of research. Indonesian academics have little incentive or financial backing for field research, and even less for publication in international books and journals. Foreigners who do have the time, funds and motivation are often hampered by the complicated and lengthy procedures to obtain research permits, made even more difficult by the security situation due to rebel groups.
In spite of the problems, I felt compelled to try to take an overview of the island’s biodiversity. While the text is meant for non-specialists, there is perhaps enough information to be of some use to scientists, especially in fields outside of their own. I have done very little orginal field research on my own, except for the natural resource utilization by the Kamoro group living on the south-central coast of the island (the third section of this book). For several animal and plant groups, this book is based exclusively on only one or two key texts, listed in the bibliography.
Scientific names are essential to understanding plant and animal life, anywhere. While popular names, such as tree kangaroo and barramundi, roll easier off the tongue, they tend to be very imprecise. Scientific names area a godsend when trying to name a specific animal, and no other. A single common name often applies to several species or single species can have different common names. This especially true in English where, say, the same fish can have several common names in Australia, different ones in England and distinct ones yet from the popular names of the same fish in the United States. In Indonesia, this same fish can be called by several dozen common names in that nation’s various languages, aside from the national Bahasa Indonesia. The sound made by an animal varies according the speaker. As in cock-a-doodledoo for English roosters and koko-rikoh for the French variety; Indonesian one go kukuruyuk; in nature, all the roosters make the same sound as far as we know.
All scientific names are based on the species, defined as animals or plants which can interbreed and produce fertile offspring. A donkey and a horse can breed and produce an offspring, a mule, but this animal is not fertile and thus can not reproduce. Horses can only produce fertile offspring with other horses, donkeys with other donkeys. These are species. Each species is always referred to by two names, the specific species name preceded by the genus. Thus, we are Homo sapiens. The genus, as in Homo, is always begun with a capital letter while the species are written all in lower case: sapiens. These scientific names are either italicized or underlined. A genus (plural: genera) groups similar species while families group genera related by evolution and/or body morphology. The next ‘level’ of grouping is the order, followed by class, phylum (plural: phyla) and last, the kingdom, as in Animal Kingdom and Plant Kingdom. The various scientific names are all based on Latin (and classical Greek to a lesser extent), the language of science in Europe where the Swede Carolus Linnaeus devised this system. It is called binomial (two names) nomenclature (system of naming), and was first used in the middle of the 18th Century. In our text, as in all other ones with a series of scientific names, we save space when referring to several species of the same genus by writing out the whole name of the genus the first time, then only using its first letter in front of the other species. Thus if we want to list four species of the mangrove tree of the genus Rhizophora, the text would read Rhizophora mangle, R. mucronata, R. apiculata and R. stylosa. When the species is not known, it is written as ‘sp.’ after the genus: Rhizophora sp. Several unknown species are written as spp. as in Rhizophora spp. A single name in italics refers to the genus only.
In this book we assume a general acceptance of the principles of evolution (see Appendix IV). In the roughest outline, life (organisms capable of self-replication) was first found on our planet some three billion years ago or more. Long afte life began, single-celled species made their appearance, with some eventually evolving into multicellular organisms. An explosion of different life forms occurred around 600 million years ago, and by 500 million years ago (abbreviated mya) invertebrates (animals without a backbone) and primitive jawless fishes began making an appearance. These early live forms evolved into jawed fishes and other simple animals. Fishes gave rise to amphibians such as frogs which then evolved into reptiles a bit over 300 mya. About this time, conifers and seed bearing ferns appeared in the plant world. These evolved into flower-bearing plants called gymnosperms. Reptiles evolved into birds and mammals, starting around 150 mya. Our own hominid ancestors split off from the line of chimpanzees from a common ancestor some six mya. Humans achieved their ‘modern’ bodies only around 250,000 years ago. Many of these dates are changed by new discoveries and advances in paleontology, the science of fossils. I also assumed in the text a general acceptance of the shifting around of large bodies of land in what is called ‘continental drift’. This states that all of the lands on this planet formed a single mass called Pangaea. This split into two supercontinents, called Laurasia and Gondwanaland, starting some 200 mya. Laurasia eventually split again into Europe, Asia and North America. Gondwanaland split into South America, Africa, Australia. Over millions of years, these continents ‘drifted’ to their current positions, and they are still drifting.
Where possible in the first section of the book I have tried to give some background information on the various plant and animal groups in order to give a better definition and sense of perspective. This includes some information on the groups’ evolution and migration, where I could find material. These sections are quite uneven in extent and quality, as are my sources.
Section One: Biodiversity of New Guinea
New Guinea is the second largest island in the world, after Greenland. No other island can boast of more varieties of plants, along with a host of animals, many strange, some stunningly beautiful. There are many endemic species, found nowhere else, which fascinate scientists and laymen alike. There are huge bird-wing butterflies of shimmering colors and birds of paradise wearing iridescent plumage, some with long, weird feathers sprouting from heads or other unlikely parts of their anatomy. These birds have been called ‘the most beautiful feathered inhabitants on earth’ by Alfred Wallace who independently conceived the theory of evolution at the same time as Darwin. Here, the largest indigenous animal is not a mammal, but the flightless cassowary bird, sprouting hair-like feathers and with a killer of a kick. Most of the large indigenous mammals are marsupials, completing the gestation in the mother’s pouch. And we have the echidna, which, along with Australia’s duck-billed platypus, is a unique mammal in laying eggs, not giving birth to live young. Its defense is to bury its head, ostrich-like, but with a back full of porcupine spines to deter predators. Before the relatively recent arrival of humans and dogs, echidnas had nothing to worry about: the largest indigenous carnivorous mammal is no bigger than a small cat. Another group of mammals, huge fruit eating bats called flying foxes, patrol the night skies.
While there are no weights or measurements given, thus no Guiness Records to surpass, here goes the list of the biggest is not necessarity the best (thus no Birds of Paradise or rainbowfishes or tree kangaroos).
1. the world’s largest butterfly, the swallowtail: Troides alexandra
(and the second largest too: Troides goliath)
2. largest wing area in a moth: the Hercules Moth, Coscinocera hercules
3. world’s largest pigeons: the Southern Crowned Pigeons, Goura sheepmakeri.
(there are two other species in the genus, ranked second and third)
4. largest tree frog on earth: Litoria infrafrenanta
(over 13 cm, bright green and not shy with humans; barks like a dog to announce sexual desire to the world, but intended only for the female of the species)
5. largest montreme: Long-Snouted Echidna Zaglossus bruijni
(out of only three echidnas - egg-laying mammals) on earth)
6. world’s largest bandicoot: Peroryctes broadbenti
7. the largest katydid (bush grasshopper) : Siliquofera grandis
8. the world’s largest mosses : Dawsonia spp. (anyone care?)
9. the longest lizard on earth: Salvadori’s Monitor, Varanus salvadorii
(said to reach five meters or more but never scientifically measured over three meters; perhaps the long version is a yet-undescribed species, thus ranking among the world’s greatest ecological enigmas)
10. the most massive orchid plant: Grammatophyllum speciosum (a monster weighing two tons was exhibited in London in 1852; the flowers are 10 cm. wide.)
11. world’s tallest banana : Musa sp. (all bananas are Musa; same comment as for #10)
12. the tallest tropical tree: the Klinkii Pine, Araucaria hunsteinii
(how tall is that? compated to the tallest, the California redwoods?)
13. the smallest parrots of them all: of the genus Microspitta
14. the world’s largest crocodile : the salt water, estuarine or Indo-Pacific Crocodile, Crocodylus porusus. (Here measurements can be be wildely exaggerated, as the 10 meter and one centimeter monster supposed to have been caught in what is now Bangla Desh in the 1930s, and very likely untrue; the largest crocodiles, of this species for sure, are probably in Australia where they have enjoyed rigourous protection and could well be reaching a still-horrific eight meters.)
(adapted from Sekhran, 1994, p. xxii; the parenthetical additional information, along with the snide comments, are my own)
New Guinea covers 792,540 km2, and stretches 2400 km in length. It is almost evenly divided by a north-south frontier between the independent nation of Papuan New Guinea (PNG) covering 370,559 km2 and the Indonesian province of Irian Jaya with 421,981 km2. The island extends over an area about twice the size of California. There are some 2.1 million people on the Irian Jaya side (of which about 40 per cent are recent migrants from the west) and 4.7 million souls, almost all Papuans, in PNG. The political boundary follows the 141st meridian or degrees east of Greenwich. A long mountain cordillera stretches from almost one end of the island to the other, with peaks reaching 4000 meters. These mountains divide New Guinea into distinct north and south zones, as the mountains run east-west, parallel to the long axis of the island itself. The deep Pacific Ocean washed the north shore while the shallow Arafura Sea marks the southern boundary of the island.
Thanks to the inclusion of the flora and fauna of Irian Jaya, Indonesia has recently achieved the top ranking in biodiversity, surpassing the previous champions, Brazil and Columbia. (Supriatna 1999) And Indonesia also tops of the world’s list of unique and exotic plants and animals: the highest number of endemic species of all nations on earth. (Australia comes in third.) Indonesia also leads all other nations with 515 mammals, comes in third with its reptiles (511, but many more being added from west New Guinea) and fourth in bird species diversity, with 1534 (Columbia tops this list with 1721). (de Fretes 2000) With almost half of the nation’s total biodiversity, it is no wonder that Indonesia is not about to grant independence to the western half of New Guinea.
The fact that Irian Jaya hosts nearly half of the country’s animal and plant species, is due in no small part to the fact that some 90 per cent of the province’s forests still remain largely intact. Irian (and PNG) straddles two major biological regions, lying at the cross roads of the Australian and Asian animals and plants. The western half of the island fall into four major areas, relatively isolated from one another by geography: the northern and southern lowlands, split by the broad central mountain range, and the Bird’s Head, attached to the main body of New Guinea only by a narrow strip of land. Each of these four regions has its own, distinctive biota. The large islands off the coast, Biak and Yapen in the north, the Raja Ampat to the west, also make up separate and unique areas.
The following list, adapted from Sekharan 1994, gives a fair idea as to the total species in each of the major taxonomic categories. Most information came from the western half of the island (PNG), but where all of New Guinea is included, we preface the species number by an NG designation.
fungi PNG 2400 known, 90,000 estimated
lichens NG 495 known
mosses (Bryophyta) NG 850 known, 1000 estimated
liverworts (Bryopyta) NG 700 known
Pinopyta (pines et al), plus
Magnoliophyta (flowering plants) PNG 16,000 estimate
There are at least 15,000 species of vascular plants but while species endemism is high, endemism at the family and generic levels is low.
sponges (Porifera) PNG 90 known, 2000 estimated
Scleractinia PNG est. 700
Alcyonaria (octocorals) Magang 118
Land mollusks NG known, over 481; estimated: 1000
Freshwater and brackish mollusks NG over 165 known
marine mollusks PNG over 950 known
marine nudibranchs 700 Madang Bay only
Arthropoda/Crustacea, freshwater PNG 87 of which endemics = 31 = 36%
Crustacea marine/freshwater 198 from Madang Bay only
Uriramia/insects... PNG estimate: 300,000
Echinodermata Torres Strait only: 177 (Clark, 1921)
Sharks/Chondrichthys PNG 91
Osteichthys/all bony fishes PNG 2055 known, 3000 estimated
strictly fresh water bony fishes NG 214, of which 149 endemic = 70%
Amphibia/Anura (frogs) PNG 193 known; 115 endemics = 60%
Crocodylia NG 3
Testudines (turtles) PNG 13; of which 3 endemics = 23%
Sauria PNG 184 of which 59 endemics = 32%
Serpentes PNG 98, with 32 endemics = 33%
505 amphibians and reptiles; 46% endemic to New Guinea
Aves PNG 644 of which 76 endemics = 12%
Mammalia marine PNG est. 25
Monotremes 2, with one endemic = 50%
Marsupials NG 71 of which 60 endemics = 84%
Bats 75 known for NG, with 57 endemics = 76%
Rodents 58 known for NG, 49 endemics = 84%
In the last general category, mammals, murid rodents and pteropodid bats are the richest in species numbers. And no one has question the island’s claim as to holding the richest marsupial fauna on earth.
Combining the two most complete species lists (Beehler, 1993 for PNG and Petocz 1989 for Irian Jaya) we have a total of 182 amphibians for the island and 511 reptiles. (See Appendix V) We are not certain as to what has been added to the PNG side in the past decade, but on the western side of the border the CI surveys have added over 30 amphibians and many lizards. In Irian Jaya, the mammals surveyed through 1990 number 125, of which 58 per cent are endemic; of the 601 bird species, 50 per cent are endemic, along with 37 per cent of the 223 reptiles. (de Fretes, 2000)
When we consider biodiversity, a humbling perspective comes from the fact that scientists have named and described ‘only’ some 1.8 million species, with estimates of the remaining, undescribed ones, running between 3 and 30 million. Add this to the fact that the species alive today represent less than one per cent of the total on our planet since life began on Earth (Townsend, 2000).
For biodiversity, as in other subjects, size does matter, but it is not enough. Indonesia’s 18,000-odd islands only make up a land mass equal to that of Mexico. Location is just as important: the closer to the tropics, the better. Altitude comes into play as well: the higher above sea level, the greater the possibilities of more eco-systems with different biota. And last but not least, there has to be enough specialized scientists with sufficient time and funds to survey and describe the existing species.
Indonesia lies at the world’s center of animal and plant megadiverstiy. It spans one eighth of the world at the equator, with one foot in Asia and the other in the Australian region. Each of these two major centers evolved a distinct set of plants and animals, due to their mutual isolation during the past 200 million years of the evolution of life on earth.
Irian Jaya is home to 652 species of birds (including 39 endemics), out of a total of 762 on the island if we add those of PNG. These include 36 species (out of a total of 42) of the bird of paradise family, and a host of other gems in its aviary. The largest pigeon in the world is also the most stunning: a casque of delicate feathers and bright red eyes identify the three species of crown pigeons. We also have male bowerbirds which decorate their ground nest with berries and flowers (and bright bits of plastic, if they find any), grouping items of the same color in tasteful displays to attract passing females. New Guinea is the home of the world’s richest radiation of kingfishers, with 26 species, as well as fruit pigeons, parrots and honeyeaters. Megapode birds build huge nests to bury their eggs which hatch thanks to the heat generated by the decaying vegetation. A typical forested lowland habitat supports some 200 different breeding bird species.
Crocodiles share the same hatching method as the megapode birds. At birth, even the smallest juveniles already look fierce. There are no cute little crocs. Especially when they grow up and become the huge adults. Occasionally some of these makes a habit of killing humans. A single male crocodile was held responsible for 55 human deaths before it was finally dispatched in 1970 on the south coast. It was the Indopacific species, which can grow to a dreadful seven meters or more. There are also smaller but endemic fresh water crocs. One species had been accepted by scientists while another awaits the awarding of separate species status. Among the lizards of Indonesian nationality, we have 140 species grouped into 32 genera and six families. The skinks dominate the numbers, with over 65 per cent of the total numbe of reptiles. (Supriatna 1999) These are diveerse, small animals, less than 20 cm. long and more numbers are being added to the list.
The PNG side of the island, in 1993, had counted 505 species of amphibians and reptiles, just about half being endemic. (Beehler, 1993) Many others have still not been described by scientists. The total could well reach over 700. And there is no reason for the Irian Jaya side not having just as many species of amphibians and reptiles as the PNG side. At the last count, Irian’s number for reptiles and amphibians came to 330 (Supriatna 1999) but each new survey adds considerably to this number. Irian’s amphibia fall into four families with 20 native genera, with 98 species of which 36 are endemics. Some 80 per cent of these frogs belong to the Hylidae and Microhylidae families. (Supriatna 1999) They exhibit a wide range of habitats, from underground, to terrestrial and streams to trees. The wide range is due to their bypassing the tadpole stage. A single survey added just about 30 per cent to the number of frog species in Irian with other surveys having more species in the scientific pipeline.
With over 200 frog species in PNG alone (and some still awaiting this status) there are more of these animals in New Guinea than any other comparable sized area. Indeed, the island is considered a major center of frog evolution. Colors and body patterns abound on these animals. Hardy specimen live as high as 3850 meters. Some are tiny and some huge: the Arfak River Frog reaches 160 mm and provides a tasty meal to the Papuans who catch them with spears or bare hands. No one wants to eat the even larger cane toad which was introduced to the island in a misguided attempt to control insect pests but has devastated much other native life.
While not very commonly seen, lots of snakes crawl around New Guinea, including the fearsome taipan and the death adder. But most snakes are not harmful to humans, and some can be downright beautiful: the green tree python displays tasteful markings on a yellow body as a juvenile, turning to emerald green in the adult. Irian snake species so far survey total 75, with the only endemic, Heurnia, is restricted to the Mamberamo drainage area. (Supriatna 1999)
The waters around New Guinea hold a spectacular variety of fishes, invertebrates and other marine life, second to none. The fresh water and estuarine varieties are just as fascinating. There are fresh water sharks and sawfishes; colorful rainbowfishes with many unique species; huge catfishes and archerfishes spitting deadly accurate insect-snagging jets of water. And the mudskipper fish which can spend long periods out of water and even climb trees in search of their meals. There are some 1,800 species of marine fishes and 350 fresh water one, with at least 250 of these found in Irian.
The waters off New Guinea fall into two very distinct zones. In the south, along most of the Arafura Sea, heavy siltation in the water prevents sunlight from filtering down to supply the vital ingredient for photosynthesis. Corals need this, so they are hardly found in this zone and the ecosystem built around them does not exist. Starting at Etna Bay, mid-way around Irian Jaya’s south coast, and to the west, the waters clear and rich coral life supports a thriving and diverse eco-system. This is also true along the island’s north coast. Recent studies in the Raja Ampat islands are revealing an unsuspected variety of marine life, partially thanks to converging currents. Indeed, estimates for just south-east Misool and western Waigeo islands in the Raja Ampat group run to over 1000 species! (Supriatna 1999)
One survey, in Madang Lagoon in PNG, revealed an unusually large number of marine invertebrates. Scientists found 1000 species of hard corals, the main reef-builders. Along with the sea pens, nudibranchs, crustacea and other groups would indicate that this relatively small body of water may well hold the highest species richness and diversity of any site in the world. This is definitely true for mushroom corals: in 1993, of the 42 described species, 36 were identified there, along with a new species. Scientists studying this lagoon also found 600 species of nudibranchs and expect anywhere from 100 to 200 more. Add to this close to 200 species of marine and freshwater decapod crustaceans in the immediate Madang region.
Many new species of mammals have been discovered in New Guinea during recent years, bringing the total to 227 for the moment. Out of these, only 164 have been identified in Irian, (Supriatna 1999) but it is very likely that more will be added. The best known and most distinctive mammal group, the marsupials, came from the Australian region, but the more numerous rodents and bats arrived mostly from the west, making their way across what is now the Indonesian archipelago. New Guinea hosts the largest rat species in the world, Hyomys goliath.
Despite its small size, New Guinea has been ranked 12th in the world for the endemic variety of its large butterflies. This includes the world-renown birdwings (Ornithopera and Troides genera), the largest and among the most beautiful butterflies on earth. In the three families most prevalent on the island, Papilionidae, Pleridae and Nyphalidae, 56 of the 303 species are endemic. The most diverse genus, Delias, is found mostly in the highlands, with almost all being endemics. When recent counts are completed, the species total for the island will surpass 1000 (with over half endemic) butterflies, compared to a total of 380 for Europe, 383 in Australia, huge areas in comparison. Only the Malay Peninsula, with a current count of 1,031 species can compete with this figure.
Aside from the butterflies, insect life on the island offers some not such splendid but intriguing varieties. There are more than 800 kinds of spiders, including a particularly nasty customer, the bird-eating variety, alias Selenocosmia carassides. These large and aggressive beasts live out a role reversal, eating small birds which normally feed on insects, including other spiders. Much prettier, we have many orb-weavers with intricate webs. Beetles come in an endless variety, some pests, some beneficial. One that combines both of these attributes, the sago grub, goes under the scientific name of Rhynchophorus ferrugineus. Roasted or alive, they are a nutritious source of protein to coastal Papuans, as well as a ceremonial food for the Asmat tribe. Beetles come in all shapes and sizes, including a good number of beautiful species. Experts have estimated that just Irian Jaya holds at least five per cent of the world’s insect fauna. (Supriatna 1999)
The plethora of insects, perhaps 200,000 to 300,000 mostly undescribed species, pehaps half or more endemic (out of a world total of about one million describes ones), owes its existence to the great variety of plants. The island’s vegetation has evolved to become just as diverse and unique as the animals. Estimates range to over 25,000 or more species of vascular plants (ferns and flowering ones), with up to 90 per cent of the flowering ones found only in New Guinea. While there are no endemic plant families, some 124 genera grow nowhere else. At least 30 per cent of the plant species are still undescribed.
New Guinea is an orchid champion, with perhaps some 3000 species and although some of these may well be synonyms, there are probably several hundred species awaiting discovery. Be that as it may, the most rational estimate for the orchid species for the island has been pegged at 2200 to 2800 but this still represents some ten per cent of the total species of this flower on earth. As with other organisms in New Guinea, this high diverstiy can be attributed to the recent rapid development of the island, with its high rainfall tropical climate favorable for plant growth. New areas for plant colonization developed, especially in the many relatively isolated mountain niches. ‘The resultant explosion [or orchid species] is still occurring. It is a spurt of evolutionary expansion in which species are continually developing and changing in a way that makes those attempting to classify them tear their hair out.’. (Lavarack, 2000).
As with many other groups, orchid taxonomy and clasification is far from being set in concrete. This is especially true for New Guinea where orchid collecting for scientific purposes has been restricted by the difficulty of the mountainous terrain (much of the interior of the island) and the difficulty of obtaining research permits (of any kind, not only for orchids) in the Indonesian side of the island for security reasons. Most of the work on the island’s orchids are still based on the work of two extraordinarily dedicated men, pulished in the early years of the 20th century. Rudolf Schlechter did his research and collecting in what was then German New Guinea (the northeast of the island) while J. J. Smith documented these flowers in the western (then Dutch) half.
It is estimated that New Guinea holds over five per cent of the world’s 270,000 described flowering plant species. The gaps in the biodiversity of plants come from the lowland forests which are poorly collected. Here the number of endemic tends to be quite high and species are wide spread due to the large area covered by the eco-system. In the highlands, the number of species drops drastically and the ranges of some species are quite restricted. Many mountains lie in ecological isolation, with few species, but each mountain has its own group of endemics. At the last count, some 2390 species of fungi had been described, but estimates range from 15,000 to 90,000 as to the total number of fungi species on the island. Bryophytes, mosses and liverworts species lists have not yet been published although some research has been conducted with these plants.
Aside from the orchids, some of the better known unusual plants in New Guinea include an abundance of pitcher plants which have adapted to nitrogen-poor soils by consuming insects. Giant anthouse plants, Myrmedodia brassii, host colonies of ants living in intricate passages who defend their homes against all comers. Other ant colonies build dark nests on tree trunks and branches, sting anyone bothering their host but allow some birds to nest inside, along with small frogs and lizards.
The southern coast of Irian holds the world’s largest remaining mangrove eco-system. While the north coast mangrove species closely resemble that of the Indo-Pacific, in the south we have a distinctive system with at least nine species not found in the north. While both shores have the staple sago trees, they are over-exploited in many areas to the north while remaining under-exploited in the south due to the small population base. With less then two inhabitants per square kilometer, the 300 plus kilometer stretch of mangrove coast in the Kamoro area is a veritable supermarket for those who know what to look for and when: and endless supply of plants, fish, crustacea, mollusks, birds and other animal groups.
Due to its geological history, Irian Jaya is made up of four main areas of biodiversity: the north, the south, the Bird’s Head and the highlands. In these areas, different geological histories resulted in different vegetation and, to a lesser but still considerable degree, different animals. Due to local speciation and many barriers to dispersal, most plant and animal species have restricted ranges, resulting in a high degree of endemism.
On the south coast of Irian Jaya, the mountains rear up in abrupt steep slopes from the alluvial plain. Here it takes less than a half hour’s drive along the Freeport road to pass from the tropical rain forest to the montane moss forest usually bathed in mist and with eerie lichens and mosses hanging in huge streamers. Not much further along the road, Alpine vegetation takes over, followed by glaciers. No other area on earth offers such fast ecological transitions. As the bird of paradise flies, the distance from the glaciers to the Arafura Sea is but one hundred kilometers. Overland, following the road, one can drive all the way to the mine area, located at less than two hours trek to the glaciers.
Aside from the Freeport road, there are very few others running from the coast to the central mountains due to the ruggedness of the terrain. Indeed, this ruggedness of the island can not be over-emphasized: it is responsible for the low human population as well as the high number of species. If much of the island’s forests are still standing and supporting the associated animal life, it is because logging companies have been unable build the roads to bring out the timber. But the same problems are also faced by scientists in trying to reach most of the interior to survey and study the flora and fauna.
Prior to the recent arrival of large numbers of non-Papuans immigrants, only a few fertile highland valleys were densely populated. And even this was a relatively recent phenomenon, due to the introduction of the sweet potato (Ipomoea batatas) from South America, less than two thousand years ago according to some sources, only 500 years ago according to others. And the number of inhabitants at the coast had been kept low by malaria. With the outside world came technology and medicine, along with transmigrants, mining, road building, logging and commercial-scale fishing. None of this bodes well for the future of the island’s biodiversity.
Troubles in paradise: threats to nature
Increasing human population, indigenous in PNG and both Papuan and immigrants in Irian Jaya, are putting heavy pressure on some of the ecosystems. More land for farming, for urban areas, indiscriminate logging and, to a lesser extent, mining, all pose threats to the existing biodiversity of New Guinea. While adequate laws protecting nature exist in both PNG and Irian Jaya, these are seldom enforced due to a lack of dedicated personnel, economics, greed, and population pressures. There is general lack of foresight and responsibility toward future generations. On both sides of the border, conservation officials cite political pressures and a lack of finances as the main reasons for of enforcement.
On the PNG side, the government has far less say in matters of conservation as most of the land is owned by various ethnic groups. Here, corrupt leaders, taking payments from lumber companies, are the major culprits in environmental degradation. The wide-spread use of firearms in PNG is also responsible for the drastic reduction of all the larger species, especially those living near human populations centers.
In Irian Jaya, firearms are much less widespread and most of the illegal hunting is done by the military and the police. Of course, Papuans hunt there too, but the use of dogs, spears, bows and arrows at least give game a better chance to survive. While in many mountain areas larger game has become quite scarce due to population pressures, the situation is much better in the foothills and the lowlands thanks to less people and inaccessibility.
In Irian Jaya, all the land not actually occupied by dwellings or permanently farmed belongs to the federal government to develop in any way it sees fit for the ‘good of the nation’ as a whole. This is enshrined in the Constitution and the Agrarian Law of 1960. There are no provisions for Papuan ownership of traditional tribal lands where their ancestors for many generations hunted, collected a variety of natural products or practiced shifting agriculture. While this may change according to the future provisions of the ‘special autonomy’ to be granted to Irian Jaya by the central government, it was far from clear as to what would happen at the time of this writing. The federal ownership of land has resulted in granting mining rights and timber concession in Jakarta, without adequate consultation of the landowners and little if any payments. And while the government makes efforts to be seen as enforcing environmental laws for a large and very visible mining company such as Freeport, regulations dealing with the timber industry are very seldom followed and enforced.
The problems of conservation in Irian Jaya have also been made worse by the large number of transmigrants who arrived during the 1980s and 1990s with financial support from the World Bank. Large tracts were cleared for the transmigration sites with little planning and less regard for nature. Most of the transmigrants are from Java and the soils or Irian Jaya are far from adequate for continuos, irrigated rice farming which is the norm for these settlers. With the addition of many ‘spontaneous’ transmigrants, estimates as to the non-Papuan population of Irian Jaya run as high as 40 per cent out of a total of 2.1 million people.
Due to the large numbers of exotic species found in New Guinea, a demand exists for them outside the island. While this is true especially for birds, it also applies to many other species whose existence is threatened by illegal exports as well as local consumption.
Dugongs (sometimes called sea cows) and turtles are heavily exploited in the region, receiving effective protection only in Australia. A major problem involves trying to establish just what are sustainable catches, then enforcing this quota. For example, some 10,000 green turtles were harvested annually in the Torres Strait in the late 1970s, clearly unsustainable, but just what the numbers are for sustainable catches (aside form what the local people use for themselves) has not been determined. In the southern PNG town of Daru, a thriving trade in marine turtles exists, although recent statistics are hard to find. In 1986 and 1987 the yearly exports of turtles was about 1300, combined with some 4000 consumed locally each year for subsistence by the Papuans. It is unlikely that this can be kept up for long. The lack of research also hampers finding the sustainable number for dugong catches. Again in the Torres Strait (the only place where some studies have been conducted) the yearly catch of at least 500 individuals can not be sustained for long as the population base is only some 22,000. At least part of the dugong meat ended up being sold, illegally (at five kinas per kilo) on the Daru market. Protected species of marsupials, such as the wallabies Macrupus agilis and M. dorcopsis are regularly on sale in Port Moresby, with at least 4000 sold in 1987. In the Timika market which serves an ever growing population of Papuans as well as immigrants, protected marsupials are also frequently on sale, snapped up as soon as they appear.
Commercial marine fished and crustaceans badly need surveys to determine the amount of sustainable catches. The only published study we have seen on the subject estimates the sustainable tuna catch off north PNG at 40,000 to 200,000 tons. There was to be a canning factory, mostly for tuna, in Madang....WAS THIS EVER BUILT AND IF SO, IS IT STILL OPERATING???? A tuna cannery on Biak Island, which operated for several years in the early 1990s, has now closed, partially due to diminishing hauls. The same could happen with barramundi fish from Irian’s south coast, especially as a recent delegation from Australia has expressed interest in the import of this species from the Timika area. No one has thought of commissioning a study beforehand as to the sustainability of the enterprise. There may already be over-fishing for barramundi in the Timika area due to the demands of a large population of immigrants, many with good salaries. Once barramundi spawning aggregations are located and over-fished, the population could rapidly collapse. As early as 1978, PNG was already exporting barramundi to Australia, to the tune of 280 tons, with no idea as to the sustainability of the enterprise.
Probably even worse, the large prawn catches in the Arafura Sea seem like a recipe for disaster. The many trawlers out of Sorong cast their bottom-drag nets (illegal elsewhere in Indonesia) far too close to shore, spelling potential ruin for the rich mangrove ecosystem. In PNG, the main species caught are the paenids, the banana prawn, Penaeus merguinesis (50% of the annual catch of 800 to 1000 tons tail weight) as well as P. monodon, P. semisulatus and the endeavour prawns, Metapenaeus spp. In the coral-rich waters off Irian Jaya, fishermen from western Indonesia use dynamite for catches, ruining the reefs in the process. Cyanide is also used for catching life fish (mostly groupers and Napoleon wrass) for the Hong Kong fresh fish trade as well as for aquarium fish. Fish are also caught for aquarium export in PNG but we do not know if cyanide is used. At the last news, angelfishes (Pomacanthidae family) were bought locally there for $12 each, with clownfishes fetching $5 and tangs (Acanthuridae family) $3. Several other species are exported as well, legally and illegally from both Irian Jaya and PNG. Other illegal exports include snakes, turtles, parrots, lories and birds of paradise. This is especially true for birds from the Timika area.
The greatest threats to New Guinea’s biodiversity comes from over-population and logging. While mining leaves very visible scars, it does not affect large areas as does logging. And in PNG, it is said that mining companies were unwilling or unable to establish the network of bribery and corruption which the logging companies have used to silence the leaders of the landowning communities. At any rate, illegal mining poses far more ecological threats than established companies under constant national and international scrutiny. While no figures are available for Irian, in PNG the annual logging rate is estimated at some 70,000 hectares. In the late 1990s, PNG retained some 65 to 70 per cent of its original vegetation cover, mostly in the form of humid forests. New laws are being written and might even be implemented in Indonesia devolving power to local governments for control over logging, but this does not necessarily mean that sustainable techniques will be enforced. There is no room for optimism on this logging scene on either side of the border: logging companies tend to pay their way out of any problems, legally or illegally.
The meaning of biodiversity (move up!!!)
The Rio Conference gave the following definition: ‘Biological diversity means the variability among living organisms from all sources, including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and ecosystems.’ Biodiversity is the variety of life, in all its manifestations. It carries the connotations that biodiversity is a good thing per se, that its loss is bad, and that something should be done to maintain it. (Gaston, 1998).
A key concept in biodiversity is that of nested hierarchies. This refers to one of the central principles of modern biology, of groups ‘nested’ within others in a hierarchy. There are three main groups: genetic diversity, organism diversity and ecological diversity, all intimately linked. (Gaston, 1998). Another author (Townsend, 2000) adds one more to the nest. He gives four levels of ecological organization: individual organisms, populations (individuals of the same species), communities (the number of populations) and ecosystems (a community together with its physical environment).
Biodiversity’s ultimate ‘nests’ are ecological systems. Each ecosystem has its own variety of plants and animals, with some overlap. There are plants and animals (led by Homo, sometimes sapiens) which can live and love in many different ecosystems, others which are restricted to only a very small habitat. Let’s examine the meaning of these two key words: biodiversity and ecosystems, before focusing on New Guinea.
Townsend (2000) defines ecology as ‘the scientific study of the distribution and the abundance of organisms and the interactions that determine distribution and abundance’. Ecosystems are based on a set of physical factors such as soil type, elevation, land form and climate. Within these physical constraints, we have a mutually dependent set of plants and animals. Aside from these, we have an essential and teeming microscopic world of bacteria, fungi and other organisms. Let us very briefly consider fungi. Aside from the well known mushrooms, fungi include mycorrhiza found in the soil. These fungi have an essential relationship with plants, helping in nutrient uptake. The tiny hairs (hyphae) of the mycorrhiza can penetrate pore spaces too small for the tree roots, thus extending the soil volume available for the plants’ nutrients and water. Another example are the types of bacteria which help to ‘fix’ (make available) nitrogen, an element essential to plants.
Moving to more complex organisms, soil insects are of tremendous value in the nutrient cycle to maintain soil fertility, especially in the tropical forest ecosystems. These arthropods include mites, springtails, isopods, amphipods, millipedes, centipedes along with some spiders, ants and termites. Unfortunately, little is known about these critters (especially in New Guinea) as they require specialized sampling techniques and scientists dedicated to a not very glamorous life-style. It takes a plethora of organisms to sustain the most popular mammals, especially Homo sapiens.
Taking a broad view, having more of the right kind of species in an ecosystem gives it more stability as more nutrients can be utilized. In a financial analogy, it’s like having a very diversified portfolio of investments. The more variety of species (stock shares spit among various companies in different countries, in our analogy), the more stable the ecosystem. Ecosystems, like financial markets, need to take risk into account. A natural or man-made disaster can devastate one’s portfolio or an ecosystem. The more diversity, the less risk. Or at least the better the chances for recovery, given time.
The degree of biodiversity in any ecosystem depends on two major factors: the food chain and the presence of keystone species. For the food chain, the greater and more varied the plant and animal life, the richer and more stable the community. Each community depends heavily on keystone species, ones that determine the structure of the community. If they die or are removed, a drastic drop in diversity ensues. Species in ecosystems have been cleverly compared to rivets in a flying airplane (Gaston, 1998): some may be redundant, and you can lose a few and still fly. But if you lose too many rivets/species or lost an essential rivet/keystone species, you can imagine what happens.
Biodiversity concerns the variety of all life, including plants and animals. These are the two most commonly known and complex ‘kingdoms’ of life on earth. The other kingdoms are just as important, but represent ‘lower’ or less evolved life forms: bacteria, algae and fungi (including mushrooms, molds and lichens). The main types of plants are mosses, ferns, cone-bearers (gymnosperms) and flowering plants (angiosperms). For animals, the two basic divisions are those with and without backbones: the vertebrates and the invertebrates. Sunlight is at the base of all life, the essential ingredient in the plants’ process of photosynthesis by which food is produced. While plants produce food, animals consume it. Photosynthesis by plants sustains the biosphere, not only by converting solar energy into food but also by producing oxygen.
The plant and animal kingdoms have been divided by scientists according to their most important characteristics into groups called taxa. The first and most important split is called ‘phylum’ (plural: phyla) for animals and ‘division’ for plants. The two main plant divisions are the gymnosperms and the angiosperms. These two divisions are covered together below. For animals, we separately describe the phyla Vertebrata (fishes, amphibians, reptiles, birds and mammals), Arthropoda (insects and crustaceans), Mollusca (bivalves such as clams and oysters along with gastropods such as snails with coiled shells).
An incomplete picture
There is no question that New Guinea ranks among the world’s most biodiverse regions. It is also an undisputed fact that while there is some knowledge of the animals and plants, much systematic research is still needed in order to arrive at even a rough idea of the existing variety of the flora and fauna. While fairly complete information is available on some groups, such as mammals, birds, rhododendrons, birdwing butterflies and fresh water fishes, other groups, especially many plant groups and invertebrates such as fresh water mollusks and bivalves are largely left in the dark. Marine resources are also cry out for more of systematic surveys.
At least some of the lack of information about Irian’s biodiversity can be attributed to the political and security situation of the province. It is extremely difficult to obtain research permits, due to the government’s responsibility for the safety of visiting scientists. So where there is a fair amount of excellent information from the pre-1963 period, little research has been conducted since then, especially when compared with Papua New Guinea. For example, the amphibian and reptile fauna of Irian Jaya are poorly known with only 329 species documented from the region as compared to 505 from PNG. These differences, probably in part at least, represent a collecting bias - the number of specimen from PNG outnumber those from Irian Jaya by a factor of 15-20:1. The same can be said for other biota as well.
It would seem obvious that the research needed in Irian should be carried out by Indonesian scientists. But as a economically poor country, the resources are lacking for field work and, unfortunately, most of the national scientists are looking for more profitable activities or are too busy with teaching duties, administration or, frankly, are none too keen to do field work. Especially not in Irian. Of course, there are some dedicated ones who might want to work in the field. But most of them do not have enough organizational skills in writing nor the command of the English language necessary to publish in international scientific journals, a major enhancement of their personal curriculum and the normal path to reach sources of research funds. Academics in this country have no need to do research or to publish to retain their jobs. So field work in all the country, but especially Irian, is neglected.
There are however a few bright spots on this otherwise dismal research horizon. During the past few decades, first the WWF, then Conservation International have conducted valuable surveys. But perhaps the most important contribution to the knowledge the province’s comes from the work of scientists (foreign as well as Indonesian) associated with Freeport Indonesia, a mining company working in the mountains near the south coast. The staff of the environmental department, along with invited visiting scientists, have conducted ecological surveys as part of the Amdal (environmental impact) process, while on-going monitoring programs provides a continuously updated source of valuable information, available to interested parties.
The Freeport project area is bordered on the east by the Lorentz Nature Reserve, a pristine, sparsely inhabited area of more than 2 million km2 and a World Heritage Site. This is the most important region for mammal diverstity in Melanesia (Mombert, 1998), complemented by its incredibly rich flora and fauna. The proximity of the reserve to the mining operations makes it specially important to maintain high standards of environmental management. This also provides a unique opportunity for the development of biodiversity programs benefiting both places. Given the similarity in habitats of the Lorentz Reserve and the Freeport project area, biodiversity studies conducted in one area will be highly relevant to the other. Thus the potential is evident for a great increase in knowledge about the province’s biological diversity. And aside from the Lorentz, there are many other areas under conservation status, especially isolated and rugged places which still hold many of nature’s secrets. Thanks to efforts by the WWF, some 20% of Irian some form of official protection.
Both the mining company's project area and the Lorentz Park cover an almost incredible gamut of eco-systems, ranging from Alpine/glacier to highland and tropical rainforest, through fresh water and mangrove swamps, ending the shallow Arafura Sea. Indeed: the Grasberg ore body lies within sight (when, in the morning, there are no clouds) of Puncak Jaya. Soaring close to the 5000 meter mark (4884 to be exact), the peak is the highest elevation between the Himalayas and the Andes. One of the world's only three tropical glacier fields (the other two are in Africa and South America) abuts the steep top portion of Puncak Jaya.
What a single, quick survey can do
While scientists have been able to work in the south-central portion of Irian thanks to Freeport’s infrastructure, most of the rest of the Irian is simply too rugged to conduct easy field surveys of plant and animal life. But modern technology is beginning to overcome the problems of logistics. Thanks to (very expensive) helicopters, Freeport has explored many areas simply too difficult otherwise. And this has opened opportunities for scientists.
From March 31 to May 2, 1998, Conservation International was able to place eleven highly qualified scientists in one of the most inaccessible parts of Irian thanks to cooperation from Freeport’s exploration unit. Helicopters ferried the scientists to the site, where they were housed and fed at the company’s temporary facilities. The Wapoga River area is located inland from the north coast, west of the Mamberamo Basin and to the east of the Bird’s Neck. Five sites were surveyed, ranging in elevation from 10 meters to 1890 meters above sea level. The Wapoga River drainage area is the second largest in the north of Irian Jaya, after the huge Mamberamo. It is one of few areas in the tropics with pristine forests, no inhabitants and very little evidence of human activity. Some logging had taken place previous to the survey but with little impact even in the small area where the trees had been cut.
The survey discovered many new species of frogs, aquatic insects, ants and plants, along with several new-to-science fishes and lizards. Other species were found for the first time in Irian. Several frog species, in rapid decline elsewhere in the world, were found healthy and well in the survey area.
The flora part of the survey covered trees as well as understory plants, including shrubs and vines. Most of the palms collected were new to the country’s central repository, the Herbarium Bogorensis, with one species of Licuala probably new to science. The trees of the wide spread genus Myristica also added a new species, and the genus Zygogynum came up with two brand new members.
In the much neglected but crucial category of aquatic insects, 110 species were collected, with 38 of these new to science. along with two new genera. The groups most intensively collected were the Heteroptera (called ‘true’ bugs), Gyrinidae (whirlygig beetles) and Zygoptera (damselflies). These groups were chosen because of their consistency in representing a range of habitats and their variations in response to altitude and habitat. It also helped that the scientist conducting the survey was familiar with these insects, having previously worked in two other locations on the island. Another member of the team, an ant specialist, collected 196 different species, of which at least 17 were previously undescribed, thus new to the scientific world.
Larger animals tend to attract much more human attention, but there are much fewer of these than insects and new species are tough to find. Nevertheless, the survey discovered three new fish species, two new rainbowfishes and a new goby. Two new lizards joined the ranks of the recognized, one large species of gecko of the genus Crytodactylus, and a skink of the genus Emoia. While no new birds were found in the 213 species identified, the researchers were heartened to see many cassowaries, Goura pigeons and hornbills, meaning little or no hunting with firearms in the area. No new mammals were found either, an event which would make world news as these animals are very well documented. Nevertheless, 62 mammals were collected, including seven species of bats and two rodents.
The biological highlight of the survey came from the frogs. The Wapoga area’s diversity was very high. Previous to this field work, 98 species of frogs had been identified in Irian. The team found a total of 47 species in this single area, including 29 new ones, a most unusual feat. In a few days of collecting, the number of frog fauna in Irian increased by a whopping 30 per cent!
II. Basic influences on the composition of Irian’s plants and animals
step one: geology
Plants and animals ultimately depends on past geology for soil components and tectonic movements which have slowly but surely placed New Guinea in its present position in relation from Antarctica to the equator through various climate zones. This huge island has not always been here. In fact, it has moved thousands of kilometers in its long history. Nor was it always a single block of land as it is today: while some of New Guinea is a chunk of north Australia, other parts were former islands. All these chunks of land were pushed together into the form we see today on the map.
The long geological history of the island of New Guinea culminated in a relatively short period during which the majority of the flora and fauna arrived from south-east Asia. This seems illogical: Australia and New Guinea are very close to one another and south-east Asia is far away. Credulity about the predominance Asian influence for plants and animals is strained even further when we learn that southern New Guinea and northern Australia were connected by a land bridge at various times in the past and as recently as about 8 to 9000 years ago. At that time, and during earlier periods, the Arafura Sea dried up. Papuans and Australian Aborigines could stroll across to exchanges genes or whatever. But it was not so easy for many plants and animals as for humans. The Homo sapiens probably arrived to Australia and New Guinea some 100,000 years ago, although this is based on scientifically educated guesses as direct evidence only goes back some 60,000 years. These ancestors of the Papuans, fully modern humans, probably came out of Africa and made their way through the Indonesian archipelago, island hopping on rafts or crude dugouts. Recent dating of bones in Java seems to indicate that Homo erectus was still living on that island between 53,000 and 27,000 years ago, thus making contact possible between them and the proto-Papuans. (Curtis, 2001)
The main factors responsible for the current composition of Irian’s flora and fauna are geological, geographical and climatological. We will examine each of these in turn and see how they inter-acted to produce today’s biodiversity.
The history of our planet has been divided into several huge geological chunks of time, starting with the Archeozoic Era, some four billion years ago, to the most recent, the Cenozoic Era which began around 70 million years ago. This current era is further divided into two major periods: the Tertiary Period and the current Quaternary Period in which we are now living. This last period is again subdivided into two epochs: the Pleistocene and the Holocene. The Pleistocene Epoch was characterized by the Ice Ages and evolution of the first hominids when we split off from an ancestor common with that the chimpanzees, some five to six million years ago.
For a quick tour of the ‘recent’ geology of our planet which, let’s start, say, around 750 millions of years ago. At that time all the earth’s land masses were united into a single huge continent called Pangaea, surrounded by the Tethys Sea. Whatever life forms existed way back then could move around without having to traverse any large bodies of water. This single land mass began breaking up due to movements of the earth’s crust over 200 million years ago, slowly splitting into two supercontinents: Laurasia (today’s North America, Europe and Asia) and Gondwanaland (the rest: South America, Africa, India, Australia and Antarctica). Later, these land masses also to split up, separating into today’s continents.
All of the planet’s major landmasses ride on huge platforms called tectonic plates, bodies of land ‘floating’ on top of the earth’s molten interior. Some hardly move. Others have drastically shifted their position on the surface of the earth. These may move slowly by human standards, but nothing can stop them - except another tectonic plate. When two of these plates meet, they crunch and you can be sure of fireworks: volcanic explosions, earthquakes and lots of upheaving and ‘subduction’ meaning the leading edge one plate goes under the outer edge of the other one. This is what happened to Australia, and a bit of its northern edge, now New Guinea.
The reason we went back so far in time is that in order to understand Irian’s plants and animals is that we must be aware of the fact that when the land masses became separated by ever-wider bodies of water, the evolution of plants and animals took place in relative isolation. While some life forms could and still can move great distances over (or on) bodies of water, many can not or are reluctant to do so. But even if the distance between Australia and south-east Asia was great, there could have been some bodies of land in between, allowing some species to ‘island-hop’ between these two quite different centers of biodiversity.
The land mass which was to become Australia was firmly attached to Antarctica until the two parted company some 85 million years ago. At that time, Aussie-land was much further south than its present location. Around 70 million years ago, Australia started to move north, pushed on by sea-floor spreading and other factors. At this time, northernmost Australia and what was to become the island of New Guinea were submerged under the sea. When bits of this land appeared above the water surface, in the late Eocene Epoch, the northernmost part of Australia was located at 35 degrees south, the latitude of Sydney today.
There was still a long ways to go, but by then plants and animals were already well on their way to evolving into unique forms on this isolated land. The most unique of these were the marsupials, mammals which ‘raise’ their young inside an outer pouch shortly after fertilization, as opposed to the mammals elsewhere, the placentals, where the embryo stays inside the mother’s body until ready to face the world at birth. There were also egg-laying mammals but we must remember that aside from these animals, the Australian continent also produced many unusual reptiles, ratite (flightless) birds, insects, mollusks and other animals aside from plant species such as cycads, austral and archaic gymnosperms and the trees of the Nothofagus genus. Due to the long evolution which took place when Gondwanaland was still one land mass, some of the animals and trees have close relatives in South America, once part of this super-continent before it drifted off far to the east. In fact, some South American life forms are closer to those of Australia then to North America as the land bridge of Panama was formed only recently (geologically speaking), some three million years back.
When we consider Australia’s influence on New Guinea, there is crucial factor to take into account: the changes within that nation-continent. Over the past 50 million years, much of Australia went through four major ecosystems due to temperature, latitude and rainfall changes: from tropical rain forest, to savanna to grassland to the present great desert extensions. (Townsend, 2000). While a relatively small portion of south-central New Guinea can be classified as savanna, most of the areas close to Australia are covered with tropical rain forest. Today, we find similar tropical rain forest in only two very small areas in the north-east corner of Australia.
After its long, leisurely and unimpeded move northward, Australia became much more interesting in the Middle Miocene, some 15 million years ago. By then it had come in contact with the huge Pacific plate as well as what is called the ‘proto-Indonesian arc’. This is a huge fault zone, an arc which is now delineated by the southern edge of the Indonesian archipelago. Bits and pieces of Australia’s north coastline had broken off at various times during its northward progress, submerging and emerging as islands from the ocean surface. These were the bits which would eventually coalesce to form the bulk of New Guinea.
As Australia’s leading edge entered the tropical zone, moderate uplifting had begun in the area which was to become New Guinea. Prior to its sinking, the southern part of New Guinea (northernmost Australia) had emerged in the Eocene and Oligocene epochs. The land rose again during the past 10 million years, forming marshy lowlands. This rise in the north of the Australian plate combined with many other forces, working together to make New Guinea one of the most complex geological areas in the world: the leading edge of a continental plate (called the Sahul Shelf) crunching with other plates and an inner and outer series of island arcs. Their structure can now be seen in New Guinea’s two parallel mountain systems, the north and the central one. A discontinous yet very evident band of ophiolites in the northern part of New Guinea is another evidence of geological activity and complexity resulting from tectonic plate intersections. What is now New Guinea, riding on the northern margin of the Australian plate, collided with southward migrating volanic arcs which stuck to our island. The ocean crust, originally created by sea-floor spreading, was uplifted to form the now-present ophiolites which lie alongside the metamorphic belt of the central mountains.
The ophiolites are composed of oceanic crust which is seldom uplifted, as this crust is usually subducted (forced under) continents, into the earth’s mantle. Where the crust does ‘surface’ it is evident by its mineralogy, different from its surroundings. Ophiolites can produce nickel concentrations in mineable quantities, such as at Gag Island (between New Guinea and Halmahera) and at Soroako in Sulawesi. The different mineralogy of ophiolites affect soil types which in turn influence vegetation. And vegetation determines the insect fauna, at the bottom of the food chain for higher animals. As an example, we have Waigeo, a large island just west of Sorong, on the western tip of the Bird’s Head. The island is basically an ophiolite which ‘supports endemic taxa in nearly all groups [of insects] examined’. (Beehler 1993)
One of the main factors in this complexity was an east-west row of islands riding on the edge of the Pacific Plate, called the Outer Melanesian Arc. New Guinea pushed through this previously unbroken island arc, with some of the land added to its bulk and other chunks shoved to the east or west. The independent evolution of plants and animals on these smaller islands explain why some species are found only to the east and west of New Guinea, and not on the main island itself.
Some of the islands in the Outer Melanesian Arc became part of the northern stretch of today’s central mountain cordillera. But for several million years these mountains were nowhere their current height: it was not until some five to three million years ago that the crunching plates, along a major fault line, raised the central mountain range to its present elevations. Much volcanic activity occurred during this upheaval, adding igneous rocks to the mountain ranges and resulting in several areas of concentrated mineralization, such as the Grasberg. The tectonic collision to the east formed the Banda Arc and the Lesser Sunda Islands, along with large chunks of south and east Maluku. This was a time of great shattering, uplifting, downfaulting and in general the rearranging of today’s Indonesian archipelago east of Bali.
Step two; the Ice Ages
By the latter Pliocene, New Guinea’s basic land forms were in place: a central cordillera of high mountains with a relatively flat zone on both sides. Volcanic activity stopped in the highlands some 200,000 years ago but tectonic uplifting continues, mostly in the northern mountains. The rate of growth reaches about three meters every thousand years, spectacularly fast in geological terms.
Geological forces were still at work, but as far as the animals and plants were concerned, another factor became even more important: the climate changes brought on by the Ice Ages.
As the leading edge of the Australian continent had edged northward, it entered the tropical zone, with its marked effect on the flora and fauna. This progression plus the growth of the mountains changed the pre-existing dry, desert climate of the north edge of Australia into a zone of heavy rainfall. The new climatic conditions favored the entrance of animals and plants which had evolved in this setting, to invade the ‘new’ land. And most of this flora and fauna came from the west, from south-east Asia, which had long evolved its life forms in the tropical setting.
But there was a crucial difference and a unique set of opportunities for the new invaders. During the Pliocene Epoch, the last of the Tertiary Period, and the Pleistocene Epoch, the first in the current Quartenary Period, (five to two million years ago) the central mountains uplifted in New Guinea. As they approached today’s elevations, a new, temperate mountain area was created on what had been a relatively low-lying tropical island.
The Ice Ages of the past two million years, with its accompanying climatic fluctuations raised and lowered the world’s sea level by as much as 200 meters. Water increased in volume as it turns to ice, so when large quantities of sea water turned to ice at the poles, the surface level was lowered. This lowering of sea level resulted in continuos dry land from what is now the Malay Peninsula all the way to Bali: all of Sumatra, Java, Kalimantan and Bali were a single land mass. The lower seas also reduced the distances between the islands of Indonesia, making the transit easier for various life forms, with mankind coming along in a trickle, starting sometime between 60 and 100,000 years ago. During the past 125,000 years, the sea surface underwent six major dips, each down to at least 50 meters and the greatest one, some 15,0000 to 20,000 years ago, to at least 140 meters below its current level. This corresponds to the greatest extent of glaciation on New Guinea, when there were some 2000 km2 under ice. By 7000 years ago, all this ice had completely melted, to reappear again some 2000 years later. Today almost all the glacier fields are gone again. These are but the very latest (and best studied) phases: the Pleistocene glacial history of New Guinea goes back over 700,000 years.
Insofar as biodiversity is concerned, what is important about the Ice Ages is not so much the glaciers - although the possible provenances of some of the fungi in the ice make for fascinating speculation, being that other similar environments are so far away (New Zealand, the Himalayas). What we must learn from the Ice Ages are the different eco-systems it created, a function of elevation and lowered temperature which dropped to an average as much as 6 degrees Centigrade below today’s means. The creation of new environments above the tropical one gave an opportunity for plant and animal speciation, an evolution which has resulted in many of today’s endemics in New Guinea.
Step three: landforms: creating a plethora of ecosystems
The plants and animals which arrived in New Guinea were adapted to the environment of their origins. Most of them settled happily in a similar environment along the coasts or in the lowlands. But climate changes and topography gave some the opportunity to evolve into forms which could thrive under different conditions than their ancestors.
New Guinea offers several major land forms, each with many different ecological zones for its biota. The southern plains and lowlands stretch in various widths from the Arafura Sea to the central mountain chain. Toward the center to the island, this can be as much as 400 kilometers, narrowing to the east and west. In Irian, it is around Etna Bay where the mountains meet the sea and the lowlands end. Most of this lowland area is alluvial, made up or eroded material from the mountains. The south coast of the island also holds the world’s largest and most diverse mangrove area, most of it from Etna Bay to the east, but with an important area inside Bintuni Bay.
The central mountain cordillera marks New Guinea’s most distinguishing and dominant feature. The mountain range varies in width from some 50 km at the eastern end, around the Paniai Lakes, to around 200 km. at the border with PNG. The highest mountains are in the south, topped by Puncak Jaya (formerly Carstensz Peak) at 4883 meters. This is the highest point between the Himalayas and the Andes, rearing up just to the east of Freeport’s Grasberg mine. Many other elevations in this range top the 3000 meter mark.
To the north of the high ridge line, several east-west oriented valleys of varying fertility support large populations. The densest Papuan villages are in the Baliem Valley, where concentrations can reach as many as 150 souls per square kilometer, thanks to a high degree of social organization, rich soils and intensive sweet potato cultivation. And little if any malaria.
To the north of the central cordillera, the extensive Mamberamo drainage (formerly, the Meervlakte) and other lowland areas separate the northern mountains, which include the relatively narrow Cyclops range. But here, as well as in the Arkfak Mountains of the Bird’s Head, a fascinating set of endemic plants and animals trace their origins to the islands of the Melanesian Arc Islands which have become part of the New Guinea land mass.
The basic landscape outlined above is subject to frequent local changes due to several factors, led by earthquakes. The PNG side, shaken by almost ten per cent of the world’s earthquakes, probably reflects the situation in the western half of the island. Other factors determining local mass land movements include basic rock types, the depth of weathering and the numerous violent rainstorms. This last scourge of nature especially impacts the landscape which has been modified by man’s burning and clearing. Rain splash erosion removes much of the thin, nutrient-rich topsoil with its obvious consequences for agriculture. In the grass-covered highland areas where burning has been a frequent hunting tool, fire not only burns the covering vegetation but destroys the top layers of the protective peat layer, leading to further erosion.
III. The plant life of New Guinea
Many factors are responsible for New Guinea’s diverse plant life, but it is a combination of location, climate, geological history and high elevations which makes the island’s botany special. When compared to other tropical areas, this islands’ 246 plant families in 1500-odd genera and some 15 to 20,000 species of vascular plants are quite small. (Note that there is no agreement among botanists as to these numbers: some double the above figures, but the totals are still small in comparison with a tropical area of similar size. A recent figure for Irian Jaya gives the number of 20 to 25,000 species of vascular plants, of which only 1800 have been collected [Barrano, 2000].) What New Guinea might lack in species numbers, it more than makes up in endemicity: over half, some 55% of the plants are only found on this island. While there are no endemic plant families, by the end of the 1980s there had been 84 endemic genera identified; but it takes a most self-assured botanist to hazard a guess on the total number of endemic species: collections, especially in Irian, are too few and far in between, with many areas with completely unknown plant complexes. There are also at least 2000 pteridophytes (ferns and allies), a rich assemblage indeed. Ferns and orchids thrive in the combination of cool climate and high rainfall found in the island’s mountain zones. This results in acidic soils, even over base-rich rock. Many epiphytes are found in New Guinea, thanks to their preference for acid humus accumulations in tree crotches where additional nutrients are provided through mycorrhizal associations.
Plant diversity and endemicity are responses to soil types, climate (especially total rainfall and its’ timing as well as temperature) and in-migration from other areas. For most of its geological history, what was to become New Guinea was either under water, low lying and isolated from migration by foreign species. Conditions started changing drastically some 10 million years ago when the larger chunks of the island reached their current position. Here New Guinea was close enough to allow the migration of Asian species of plants, the ones suitable for dispersal over relatively short stretches of water. Today’s plants, especially in the lowlands, are far more Asian in composition that Australian. The southern continent had far fewer species to begin with and many of these were not well adapted to cross over a dry belt to the tropical setting of New Guinea. The uplifting of mountains into colder air has created areas where most of the new species are found, creating the opportunities for speciation which resulted from adapting to a new milieu.
Aside from distance to south-east Asia, the position of New Guinea as the leading edge of the Australian plate exposed it major mountain building and volcanic activity as the huge tectonic plates crunched against each other. Major volcanic eruptions stopped some 200,000 years ago but not before forming soils along with the ‘parent’ rock material. The new climate also played a role in soil formation: the upward progress of mountains modified wind circulation, affecting humidity as well as temperature. While the lowlands soil seem to be very rich as one sees the profusion of vegetation, it is really but a thin layer easily leached of its nutrients. The Javanese transmigrants attempting to farm in many parts of Irian Jaya can attest to that. The highlands soils are better: richer, darker and with more organic matter, but with lots of steep and unstable slopes given to landslides. These areas are only suitable for small Papuan-style gardens. The highland valleys however are quite suitable for agriculture and support very high population densities with sweet potatoes as the main staple. Due to the limitations of the growth of this staple, Papuans do not live higher than 2600 meters, although they frequently forage above this altitude.
The plant world of Malesia
New Guinea fits into a larger botanical zone called Malesia. This encompasses the area from where the Malaysian Peninsula narrows at the Isthmus of Kra, and includes all of Indonesia and New Guinea, along with the Philippines. The boundaries of Malesia are set by three ‘knots’, natural barriers to a large number of plant genera. At the Isthmus of Kra for example, 200-odd genera found to the north make it no further south while some 375 genera from the south stop there. In the northern Philippines, another knot marks the boundary of 265 northern genera and 421 southern ones. In New Guinea we have 644 genera not found in Australia while 340 species from ‘down under’ have been unable to migrate north. To be even more specific, Malesia is subdivided into three zones: South Malesia includes Java and the Lesser Sunda Islands, West Malesia holds Sumatra, Borneo, the Malay peninsula south of the Isthmus of Kra and the Philippines. New Guinea, along with Sulawesi and the Moluccas, folds into West Malesia.
Back in 1950, a well known botanist named Van Stennis conservatively estimated the flora of Malesia at 25,000 species of flowering plants, about 10 per cent of the world total. Out of this total, he thought that some 40 per cent of the genera and an even higher proportion of species were endemic to the region. In a more recent estimate, Bob Johns gives the number of native angiosperms (flowering plants) at 3000 genera and 30,000 species, of which 60 per cent are endemic.
Let’s take bamboos as an example, one of the few kinds of plants lucky enough to have had a monograph all to itself for New Guinea (Holttum, 1967), probably outdated but far better than nothing. Of the 26 species listed for New Guinea, only one is pan-tropical. One is shared with the Philippines while the others are all endemic, mostly to mainland New Guinea, with a few spilling over into adjacent island as far as the Solomons and the Moluccas. However, as with other vascular plants, while the bamboo species endemicity is high, on the genera level New Guinea is nothing very special. All four of its genera are found elsewhere. And this applies to the family level in New Guinea flora as well. Palms present a similar pattern. Some 90 per cent of the island’s 250 to 300 species are endemic, but of the 32 genera, only two, Sommieria and Brassiophoenix are restricted to the island. Much fewer genera made it to Australia, with the list including Caryota, Calamus, Calyptrocalyx and Linnospandix along with others. For any more palm basics we have to wait until 2004 when the Kew Gardens are planning a publication on the subject, the result of an on-going Palms of New Guinea Project. (C. Heatubun, 2001, personnal communication.)
Flowering plants (angiosperms) started evolving some 150 million years ago, just about the time Gondwanaland was beginning to break up. The unusually high number of plants in New Guinea is due to two main factors: the mingling of Laurasian with Gondwanaland elements and the large number of major eco-systems found in the area, from the seas to the mountain tops.
Malesia holds one of the two major remaining tropical forest areas in the world, along with the Amazon Basin. These amazing ecosystems which are the peak of evolved biological diversity are as fragile as they are productive. While the increase in biomass can be measured at 1000 grams of carbon fixed per square meter per year in a rain forest, almost all minerals in this ecosystem are held within the plants themselves where they are safe from leaching (Townsend, 2000). Soil fertility is low and the small amounts of nutrients present are restricted to the top few centimeters, easily washed away if the protective tree cover is removed.
Synusiae: another way to divide plants
For most of us, common animals are much easier to identify than plants. We all know what a shrimp, an oyster, a bird or a mammal looks like. At this basic level, most animals are easily to ‘classify’. But out in the wild, most of the larger animals are damned hard to see, especially as most are active only at night and have learned to survive by developing a well-justified fear of man. Plants on the other hand are always there. But in most places there are just too many to attempt to identification. While we all know roughly what palms look like, and most pandanus forms are easy to learn, the majority of the flora of New Guinea is just one huge jumble in various tones of green. Of course, some of us receive a great deal of satisfaction in correctly identifying a tree or shrub or grass. But for most of the vegetation, this is an exercise in frustration. Just too many around, without enough distinguishing features (for us, not the botanist) for any attempt to identify the flora: too many shapes and sizes of leaves, too many textures to the trunks of trees, just too much variety.
There is a much simpler way, for non-specialists, to get more out of their experience with the vegetation in New Guinea. In 1918, a very methodical German (a tautology!) came up with the concept which he called synusiae. The basic division he came up with divided the plant kingdom into two groups, depending of the way they feed themselves. The first major division encircles autotrophic plants which use chlorophyll to manufacture their own food by a process called photosynthesis. This division of further divided into two main segments: the plants which stand up on their own, the trees and herbs. The second segment, that of support-dependent plants include climbers, stranglers and epiphytes. This second major division includes the heterotropic plants which obtain their organic food directly or indirectly from other plants, thus are independent of light for their nutrition. These are mostly saprophytes which live on decaying and animals, along with many plant parasites.
The self-supporting plants are the most obvious and numerous in any eco-system. Made up of trees, shrubs and herbs, the vegetation arranges itself into relatively distinct layers (five according to the experts), each with its own microclimate, each with its own balance of temperature, wind and sunshine. The shape of the treetops, called crown architecture, fall into one 23 general models. Unfortunately, these shapes do not correlate too well with the trees’ scientific identities, but they help. Also take a look at the branching pattern. This varies from nothing at all in palms (the fronds supporting the leaves grow directly from the tree’s trunk), up to a couple in the Pandanus and Sararanga species, increasing in numbers until the many branched families of Dipterocarpaceae and Leguminoseae. Leaf size is another physical characteristic to look for: they range from less than 0.25 cm2 to monstrous sized megaleaves (technically megaphylls) over 1640 cm2 and very handy emergency umbrellas. All trees flower sooner or later: well-established species once a year, pioneer species and those in secondary forests remain in almost continuos flower. Monocots, such as palms and bamboos, grow for many years then all flower simultaneously, fruit and die. While many trees bear flowers ‘normally’, along the branches, it is also quite common in the tropical rain forest to show fruit growing directly on the trunk, a phenomenon called ‘cauliflory’. This takes place in many trees and shrubs or unrelated families but vanished with altitude.
The trunk or bole of the tropical tree grows throughout the year, thus there are no growth rings to help determine age, as in the temperate zone. Bark varies considerably in texture if not so much in color. The range of bark colors runs the gamut from black to white, but the variation between trees is quite minimal. The external root systems, with a few basic and very obvious forms, help in identification. As the roots go only some 30 cm into the soil (there is little nutrients below this depth), the trunks are often stabilized by ‘extra’ supports, buttresses of varying type: plank, high, low and spreading, flying buttresses. There are also trees braced by stilt roots (Syzygium, Rhizophora among several) and others showing bracing in the form of ‘elephant’s feet’, a series of contiguous rounded ‘toes’ at ground level.
Support-dependent plants: climbers, stranglers and epiphytes
The climbing adaptation has developed in many plant families, but some 90 per cent of the climbers are tropical. They are only second to trees in overall biomass. Some are poisonous to humans and animals. There are climbing palms (rattans) which can reach a length of 240 meters, but about one third of that is more common. Other families with climbing members include the Ochidaceae (vanilla) and Pandanaceae (genus Freycineta). Stranglers belong mostly to the genera Ficus, Schefflera, Clusia, and Timonius, all of different families. There are no stranglers in temperate forests. They usually start life with seeds germinating high up a tall tree, usually in a fork between the trunk and a large branch: an epiphyte. But then they send roots down to the ground, more and more, Eventually the host tree dies and after its trunk rots and the aggressors’ roots encircle an empty space.
The third type of plants needing support, the epiphytes, include flowering plants as well as ferns. The abundance and variety of this type of plant (over 30,000 species), makes for a striking difference with temperate forests. Among these, we have the orchids, a giant assemblage with more than 25,000 species, of which some 5500 are Australian-Asian. These wonderful plants have scored an unequaled success in the tropical forest canopy. There are also many successful epiphytes among other monocot and dicot families, with the most total species in the American rain forests, their numbers surpassing those found in Africa or Asia. Everywhere, epiphytes reach their most luxurious abundance in the wet, mid-montane forests. There are less species but the tremendous biomass of epiphytes is a sight to behold. Some epiphytes even grow on leaves! They do not require food from their host, except for mistletoes (Family Loranthaceae) which are abundant in all tropical rain forests. These are partially parasitic, as well as being epiphytes. The root systems of all epiphytes often host ant nests. This greatly benefits the plant through the minerals in the debris gathered by the ants.
The myrmecophilous epiphytes have specialized in making attractive homes for ants. Commonly called anthouse plants, they have developed cavernous, organs meant as ant nests, by modifying their rhizomes, stems or leaves. The plants gain by receiving extra mineral nutrition (brought in as derby and the decomposing bodies of dead ants) and a measure of protection. The ants gain by having a ready-built home with all the comforts. Several different families of plants have special modifications to serve specifically as ant nests. These include eleven species of the fern Lecanopteris (Polypidaceae) with swollen, fleshy and cavernous rhizomes. There are also three genera Dischidia, Dischidiopsis and Hoya of the Aslepiadaceae family with ant-nest modifications. But the greatest number and diversity comes from the Rubiaceae family of angiosperms, of the tribe Psychotrieae, with five genera and over 150 species. Two genera seem to have undergone the greatest modifications for the ants’ sake: Myrmecodia (with some 50 species spread around Malesia and the Pacific) and Myrmedoma (with two species, endemic to New Guinea). These plants are the most specialized for the most hospitable chamber form and function, with massive , honeycombed, tuberous stems. They are invariably inhabited by ant colonies. The chamber could also have water-storage functions.
The vast majority of epiphytes would find it impossible to germinate high up in a tree. However, the ‘ground’ is prepared for them by non-vascular epiphytes such as bryophytes (mosses and liverworts) and lichens. This ‘bed’ provides the right environment for ferns and flowering epiphyte seeds to germinate.
Bryophytes are the most diverse in the tropical rain forests, with some 2000 moss species and 2000 liverworts. On a higher level, they are not so diverse: 90 per cent of all bryophytes belong to only 15 families. From the lowlands, bryophytes increase in diversity and density reaching a maximum at the mid-to-upper montane, then decline again with higher elevations. These plants like it when it’s cloudy, foggy and cool. The bryophytes thrive best in the Nothofagus-dominated rain forests of New Guinea. While mosses and liverworts travel better, as their spores spread better than seeds. But New Guinea can boast of one of the highest rates of endemism for bryophytes. For example, the genus Plagiochila has 47 endemics out of a total of 59.
Lichens are the poor relations of bryophytes in the non-vascular epiphyte category. As one botanist put it in an understatement, ‘they are not among the more striking elements of the rain forest’. Lichens are both inconspicuous and out of reach, a combination which discourages even dedicated scientists. They grow high up in the forest canopy and blend in with the host tree’s bark. These organisms are the result of fungi-algae symbiosis.
Saprophytic heterotropics: bacteria and fungi
These very simple organisms, which do not photosynthesize their food, are at the ragged edge of the widest definition of plants. In fact, in most classifications, they are split off from the plants, with their own kingdoms. Be that as it may, they occur in both temperate and tropical forests to play an essential role in nutrient recycling, much more so than the soil fauna of protozoa, nematodes and oligochaetes, along with small and large arthropods. Of course, the animals also play an important role in the forest eco-system recycling. Termites above all, but also wood-boring beetles break down dead vegetation high in cellulose and lignin. These relatively complex organic compounds are a relatively tough nut to crack for simple organism. The animals do the job much faster, reducing them to less complex carbohydrates, water, carbon dioxide, water and chemical ions. Thus conditions are easier for bacteria and fungi to get on with their job of further reducing the dead trees.
The whole purpose of recycling in nature is to make dead matter useful to plant life. The technical term for this is bio-absorbable. The usable nutrients in recently dead plants are not in a form which can be used by the living vegetation. This is the purpose in life for bacteria and fungi, a by-product of them feeding themselves. Some bacteria serve another essential in nature. Most higher organisms are made up of cells with a central nucleus called eukaryotes. They can not convert the nitrogen in the air to a biologically useful form. This is the job of the simple bacteria, lacking a nucleus, and called eukaryotes. Some have the ability of taking atmospheric nitrogen and converting it into bioavailable ammonia. The key to this is an enzyme appropriately called nitrogenase. These nitrogen ‘fixing’ organisms use sunlight energy, directly or indirectly, to produce ammonia. This ‘fixed’ nitrogen can then be used by plants and animals for growth and development. The prokaryotes are split into two kingdoms: Cyanobacteria and just plain Bacteria. But these creatures have needs of their own, essentially carbon compounds such as suitable sugars and organic acids, originally made by photosynthesis. For example, bacteria of the genus Citrobacter, living in the guts of termites, find plenty of carbon but very little nitrogen.
Bacteria and fungi play a crucial role in helping plants feed themselves. Bacterial symbiosis manifests itself as nodules or swellings in the root systems of nitrogen-fixing plants. The family Leguminoseae (legumes) has most it its members ‘infected’ with different species of nitrogen-fixing Rhizobium. A number of non-legume angiosperms have a close association with the nitrogen-fixing bacteria of the genus Frankia. But aside from their need for bioavailable nitrogen, these plants also need phosphorus. This where the mycorrhizal fungi come into play. These organisms enhance phosphorus uptake as well as nitrogen fixation.
The mycorrhizal fungi do their job with extremely fine, hair-like projections called hyphae. These appendages can penetrate pore spaces in the soil which are too small for the plant roots, extending the soil volume from which the tree can gather nutrients. Thus more locations for possible phosphate uptake. The symbiotic root associations give the parent plant a great advantage anywhere, but especially in nutrient-deficient soils, such as on beaches, after landslides, in poor soils such as mine waste (tailings) and after volcanic eruptions. The wide-spread tree, Casuarina equisetifolia, is one of the more obvious champions in this race to populate poor or recent soils. They are much in evidence on land just in back of beaches on New Guinea’s south coast. In fact, a long section of the north shore of the Arafura Sea is called the Casuarina Coast. These trees are also frequently seen on new soils made by changing river courses in New Guinea. They are also a crucial element in reclamation plantings. The trees’ tremendous nitrogen-fixing capabilities can be seen on Krakatoa Island, where the casuarina trees fix 58 kilos of nitrogen per hectare per year.
Besides nitrogen and phosphorus, the mycorrhizal fungi transport a wide variety of other minerals also needed by the plant. This is done by a host of species, with up to 2000 of them in a single parent tree. These fungi make the plant more competitive by helping it acquire more biomass and allow the tree to produce more offspring. Another advantage to the plant comes from the fungi’ ability to produce a wide variety of alkaloids. Transmitted to the host’s tissues, these can be toxic to animals that feed on the plant, thus giving it resistance to a variety of insects, nematodes, various pathogens as well as vertebrate herbivores. But it’s not all one-way: the plant produces sugars for the fungi, giving them a pipeline to high energy carbohydrates. This greatly help the mycorrhizal fungi over their saprophytic relatives which must obtain their food from dead organic matter consisting of complex and often toxic molecules.
A variety of invertebrates feed on the hyphae of the mycorrhizal fungi and other animals, including large vertebrates eat the fungi. Up to 80 per cent of the diet of some rodents is made up of fungi, predominantly of the mycorrhizal variety. Aside from these types of fungi, the forest floor produces brightly colored mushrooms (fungi), food for many small mammals. Some other types of fungi, found underground, release pheromones (smells) which are attractive to mammals, including humans. The advantage for the fungi is that they get dug up and can propagate far and wide. Truffles are the best known of these fungi, rooted out by pigs and dogs and eaten by humans, an expensive gastronomic delight, especially used in French cuisine.
Parasitic heterotropics: fungi bacteria and plants
Many species of both bacteria and fungi are parasites on plants and animals, including humans. Not all are necessarily bad from our point of view. Some parasitic fungi for example act as a natural control on many insect populations which otherwise would devastate plant life. Some hitch rides on the backs of insects. There are a number of weevils (a kind of beetle) of the genus Gymnopholus which live in the mountain forests of New Guinea. These large, flighless beetles feed on the leaves of woody plants high in the mountain forests of the various mountain ranges on the island. The backs of eleven species have special features which allow a range of organisms to grow there: lichens and various fungi.
Mistletoes are the most important plant parasites. The belong mostly to two families. The Loranthaceae include the greatest numbers, with 65 genera and some 900 species. The Viscaceae family is split into seven genera and about 400 species. All mistletoes are allotroptic to some degree. Some of the more evolved members of the Viscaceae are completely embedded in the host tissues.
The Loranthaceae are well known thanks to their spectacular floral displays, featuring ornithophilous (bird-loving) flowers in bright shades of red, orange and yellow. In New Guinea and elsewhere in Australasia, these flowers are routinely visited by appropriately named mistletoe birds (Family Dicaeidae) and honeyeaters (Meliphagidae). Other mistletoes feed, and are pollinated by, insects, including butterflies. This is especially true for the genus Delias, wide-spread in New Guinea. Both these butterflies and their mistletoe food plants thrive in the island’s temperate montane climates. The speciation of a great number of mistletoes in New Guinea greatly encouraged the parallel speciation of Delias at high elevations, an on-going process.
Mistletoes can also cause lots of damage to production forests, plantations and all kinds of tree crops, including citrus, fig, mango, rubber, coffee and cocoa. The mistletoes weaken the plants by taking nutrients, tapping directly into their xylem vascular systems. The worse offenders are the ones forming diffuse endophytes (plants living inside other plants).
An overview of the main eco-systems
Most of New Guinea, about three quarters of the land, lays under a mostly evergreen forest. The south coast’s seasonally dry areas show a characteristically distinct vegetation, as do the swamps and flood-plains. While the lowlands and mountain forests are quite distinct in many ways, the transition is far from a sharp one, ranging from 600 to around 1400 meters, depending on local conditions. The next higher flora transition, from montane to subalpine, occurs from about 3200 meters. The tree line depends also on local conditions, lying anywhere from around 3800 to over 4100 meters.
The diversity of the island’s plant life can best be understood if we look at a line running from the sea to the highest mountains, divided into several zones of plants adapted to the different environments. (Note that various plant communities are named for the dominant plant genus, as in Barringtonia formation.)
1. Coastal vegetation
The shallow offshore waters in many areas hold meadows of seagrasses (Thalassia, Enhalus, Helophili and Cymodocea) which offer grazing to the highly threatened dugongs. Next, starting at the edge of the Arafura Sea, the coastal vegetation resembles that found on many of the islands to the west. In many places the mangroves come to the waters’ edge, but where a strip of sand exists, the vegetation consists of creeping plants of the Ipomoea pes-caprea formation, often with colorful flowers (Ipomea, Canavalia maritima), succulents (Vigna, Sesuvium), grasses (Ischaemum muticum, Stenotaphrum micranthum, Thuarea involuta, Lepturus repens), sedges (Fimbrstylis, Cyperus penduculatus) and small landward shrubs (Clerodendron inerme, Morinda citrifolia, Wedelia biflora, Vitex). Where mangroves are far enough back and the strand is exposed, the first trees are the tall casuarinas, (Casuarina equisetifolia) looking line pines with needle-like leaves and thriving in sandy soils.
If there is coral, the first trees at the water’s edge could well be an ancient plant, the cycad, in this case Cycas rumphii as well as a well-adapted pandanus (Pandanus dubius), a tree easy to recognize. New Guinea has some 63 species of pandanus, most of them endemic. Beach pandanus includes P. tectorius and P. pedunculatus, the former with thick leaves used for walls of shelters by the Papuans.
If there is a strip of sand wide enough, there may well exist a thin strip of beach forest community, the Barringtonia association, whose canopy trees include Barringtonia asiatica, Terminalia catappa, Hernandia nymphaeifolia, Aegeciras, Cerbera, Thespecia, Pandanus tectorius and Calophyllum inophyllum. Other common beach trees include Vitex trifolia, Myristica hollrungi, one or more species of Diospyros and the very useful Hibiscus tiliaceous with its hear-shaped leaves. Common beach shrub plants include Wedelia biflora, Crinum asiaticum and Flagellaria indica.
A littoral forest is restricted to the sandy beaches and adjacent plains in extensive areas of the southwest and southeast coasts. The common canopy trees here are Pterocarpus indicus, Terminalia spp. Panchonia papuana, Sarcocephalus coadunate, Derris indica, Syzygium spp. Maleleuca spp. and, only in the southwest of the island, Acacia spp. Palms are common in the shrub and lower tree layers.
2. Mangrove swamps
No area in the world has a greater spread of mangroves, than New Guinea, especially the western half of the island. While this area hold the greatest diversity of mangroves anywhere, the number of species is not all that many. Few plants can survive in the muddy, brackish tidal waters of the mangrove environment. All of them had to adapt to living in shifting mud and a degree of salinity which would kill other plants. Only a few tree and plant families have produced a very limited number of genera able to survive and thrive in the mangroves: other genera from the same families don’t have a hope in hell of surviving in this plant-hostile setting.
Through a process called ‘convergent evolution’, plants species of very different families all came up with the same features needed to survive in the mangrove setting. These include pneumatophores or stilt roots for absorbing oxygen, salt-extrusion mechanisms and propagation via vivipary (seeds retained by the parent until germination) and water dispersion.
World-wide, there are about 50 mangrove species, trees and shrubs, with total of about 300 plants which can survive in the mangroves but found elsewhere as well. In New Guinea, there are 32 mangrove trees (erect, woody dicolylodons - excluding palms, pandanus species, cycads, bamboos and orchids), a record. While the north coast’s mangroves are pretty much the same as elsewhere in the Indo-Pacific, the south has some distinctive species, either found only there or shared with northern Australia.
In the transition zone from pure salt to brackish water, some tough trees are evident, including Sonneratia alba and species of Avicennia. This is followed by the typically mangrove swamp forest of various stilt-rooted Rhizophora, then Bruguiera on better drained areas, with the trees reaching 30 meters in height. A bit further inland, along with the Bruguiera, the drier places make space for the Xylocarpus and Heretiera species. Ceriops trees grow inland from there, on well-drained soils. At the edge of the mangrove zone, a wider variety of species can survive: Bruguiera gymnorrhiza, Xylocarpus granatum, Heretiera littoralis, Lumnitzera littorea, Camptostemon schultizii and several others. Along tidal estuaries and the lower, tidal-brackish reaches of rivers, the palm Nypa fructicans forms closed communities at the water’s edge, with a height of some 10 meters. As the waters become less saline, Pandanus lauterbachii replaces the Nypa as a monospecific stand along the riverbank.
3. Swamp forests
It is just beyond the saline mangroves that many of the coastal Papuans find their staff of life: Metroxylon sagu, the sago palm. A band of sago trees lies varying distances inland and provide the staple starch for many groups. While the work of separating the white carbohydrate from the cellulose fibers involves some hard work, it ultimately provides the most bang-for-the-buck: more calories per work-hour than any other staple on earth. In four days, a family can make enough sago to last for a month. (Of course, protein is also needed in the diet: there is none in sago) Aside from the sago, these swamps are rich in species but few predominate. Among the more common vegetation there are stands of Pandanus species, with other trees commonly found: Octomeles sumatrana, Pterocarpus indicus, Carallia brachiata, Syzygium, Disopyros, Garcinia, Barringtonia, Campnosperma brevipetiolata, and Intsia bijuga. The deciduous trees in these swamps include Terminalia complanata, T. caniculata, Pterocarpus indicus and several fig trees, of the genus Ficus. These swamps reach the middle and even the middle levers of some of the largest rivers such as the Sepik. the Fly, the Strickland. the Mamberamo and the Purari. In the drier areas of the south coast, the trees Exoecaria agallocha and various species of Malaleuca and Acacia form an open canopy.
The herb swamp vegetation is a community of mixed sedges and herbs. The dominant grass Phragmites karka can reach 6 meters in height, while the Coix lachryma-jobi grows to two meters. These two, along with Coix gigantea grow in shallow water or some of the drier swamps. The deeper swamps feature aquatic herbs, including some from the Nymphaeaceae family (Lemna, Azolla and Pistia). In the south-central part of the island, where deer were introduced less than a century ago, the grazing on the higher grasses has opened up opportunities for the low creeping grass Pseudoraphis spinescens.
Open savanna vegetation can also be found in the south-central part of the island, somewhat reminiscent of Australia. This area receives less than 2600 mm. of rainfall a year, with a marked dry season of less than 100 mm. per month. While climate is partially responsible, at least some of its origins can be traced to burning by humans, a practice kept up to this day, mostly for hunting purposes. There are three main savannah communities: Eucalypt savanna or mid-height grasses such as Themeda australis and Imperata cylindrica; Malaleuca savanna which is seasonally inundated and frequently dominated by Malaleuca cajuputi, M. leucadendron and M. viridiflora, all of which are as tough as they come: they can tolerate burning, prolonged inundation and periodic drought. A ground layer of Phragmites grass completes the picture. The third type, mixed savanna, combines elements of the first two.
4. Heathland flora
The heath type of ecosystem is found on poor soils in both highland and lowland New Guinea. In the lowlands, the padang-type vegetation grown on infertile soil, of a sandy, podzolic type developed from a substrate of quartizite and sandstone rocks. In the subalpine and alpine heaths, we also find infertile soils supporting shrubs and meadows.
Three plant families indicate heath vegetation: Nepenthaceae, Eriaceae and Epacidaceae, although there are a few other as well. All the species in the three families grow in acid, oligotrophic (nutrient-poor) or peaty soils. This means poor nutrient base, both for the self-supporting trees as well as their epiphytes. The vegetation is characterized by species with sclerophyllous (drought-resistant) leaves and lignotubers (woody tupers) projecting several stems. Scandent (climbing) branches spread from swollen trunks. The best known family of these heath-dwellers, that of Nepenthaceae, is made up of some 70 species of carnivorous pitcher plants which obtain nutrients from trappind and digesting insects.
Rhododendrons are the best known group in the Ericaceae family. There are some 850 species, with many found as pioneers at disturbed sites. In New Guinea, all species of Rhododendron which grow as epiphytes also grow as terrestrial plants. Their seeds are winged or tailed for easy wind dispersal. However, in New Guinea, the isolation of mountain habitats has resulted in independent evolution. Of the 288 species found in Malesia, almost all belong to the lepidote (covered in small scales) section of theVireya group within the genus Rhododendron. About half of the lepidotes are found in New Guinea.
The genus Vaccinium of the Ericaceae family has some 450 species, with about 240 found in Malesia. More than half of these are restricted to New Guinea. The fruit of most of these species are juicy and soft, meant to be eaten by birds, rodents and small mammals, all of which disperse the seeds widely. This is also true for the genus Gaultheria with 26 species in Malesia, of which six are endemic to New Guinea. For the genus Agapetes, with ten species in PNG and none in the west, the dispersal of seeds is only by birds.
5. Lowland rainforest
The vegetation found here is the most complex (and least understood) on earth: the experts despair and the layman can not even try to distinguish most of the different trees and plants. Bob Johns, the botanical expert, wrote (Gressitt, 1982) that ‘Few detailed studies have been made in these forests, despite their economic importance, because it is difficult to identify the species and to analyze the collected data. This broad vegetation type is best thought of as a mosaic with very varied botanical composition.’ There is little undergrowth due to the lack of sunlight filtered out by the trees. Due to the thin topsoil, many trees need buttress roots. When one of these crashes, it is easy to see that the root system penetrates only some 50 centimeters into soil. Some of the tallest and most impressive trees in this eco-system, the various Ficus species, usually start as epiphytes, send down roots and eventually choke their host.
Of great significance in retention of largely intact forests is the rarity of dipterocarps in the lowland rain forest. As a family, these account for over 80% of the world’s trade in tropical hardwoods but the family represented by only three genera in PNG, and these, although of local importance, never dominate the lowland forest over extensive areas as in Borneo. However, the major threat to rain forest comes from clearing and burning for agricultural purposes, often as a post-logging operation.
Climatic requirements for this type of vegetation include at least 2500 mm. or rainfall per year, with more than 150 mm. every month. There are some 80 tree genera and about 1200 species in the New Guinea rainforest, according to Johns. This is as rich as it gets, equaling the diversity of Borneo and the Malay Peninsula. The diversity of species and genera is greatest on well-drained lowland sites. Dominance by species and genera increase with altitude. The canopy trees, which can reach over 50 meters, have straight trunks and often are supported by buttress roots. Where crown shapes can be glimpsed, one sees a confusing variety. Ditto for branching, leaf size and shape. Due to the irregular structure, the some of the synusiae are not at all apparent.
At lower altitudes, tall palms are common, especially Gulubia and Gronphyllum, along with those in the shrub layer: fan palms of the genus Licula which grow along with tall gingers and members of the family Marantaceae. The herb layer consists mostly of ferns and a plethora of tree and rattan seedlings. Woody lianas, fleshy climbers and climbing ferns are common, especially at lower altitudes. Climbing rattans always present, but dense only in openings. Epiphytes, mainly orchids and ferns, are most common in the crowns of the canopy trees.
Rain forest composition changes gradually with altitude. On alluvial plains and gently sloping, well drained hill fans, the tallest emergents reach 50 meters or more. This the most fantastically species-rich community in the world. Just about everywhere, the canopy features Pometia pinnata, Octomeles sumatrana, Ficus spp., Alstonia scholaris and Terminalia spp. Other common genera include Pterocarpus, Artocarpus, Canarium, Palnchonella, Elaeocarpus, Celtis, Albizia, Cryptocarya, Dracontomelon, Dysoxylum, Syzygium, Vitex, Spondias and the local ironwood, Intsia. Common genera in the subcanopy are Myristica, Diospyros, Gnetum, Protium, Horsfieldia, Dendrocnide, Kibara and Pimelodendron. Higher water table means more open, lower forest. Then the frequent trees are Planchonia papuana, Terminalia complanata, Intsia bijuga and Vitex cofassus. These indicative of poor drainage and high water table for extended periods. Frequently flooded sites support a high frequency of emergent Octomeles sumatrana, and an abundance of Kleinhovia hospita in the lower stories.
The most extensive lowland forests are located on elevations which rise gradually on the gentle, low foothills and onto the lower slopes. The canopy is lower, at 25 to 30 meters, but the trees are closer together than on the alluvial lands. Frequent canopy trees here include Pometia, Canarium, Cryptocarya, Terminalia, Anisoptera, Syzygium, Ficus, Celtis, Dysoxylum, and Buchanania. Some species are locally abundant but missing elsewhere: Koompassia, Dillenia, Eucalytopsis, and Hopea.
Different rates of precipitation lead to varying vegetation here. Lower rainfall and marked dry season, as found inland from the central southern coast, gives rise to deciduous elements such as Garuga floribunda, Instia bijuga, Terminalia spp., Sterculia spp. On coastal, mainly limestone hills, the strongly deciduous element becomes more dominant, with forest of Gyrocarpus americanus, Bombax ceiba, and sometimes Acacia spp.
Trees of the same species are only occasionally found in the lowlands. While Araucaria are most often scattered 70-meter tall dominants but occasionally this species may form dense stands. Shorelines can be lined with several rows of Casuarina equisetifolia while inland the related Casuarina papuana forms quite pure and often extensive stands on shallow, stony soils (such as islands newly created by rivers) from close to sea level to 1500 meters. In the eastern part of New Guinea the dipterocarps Hopea papuana other species of the same genus sometimes cover extensive areas, in elevations up to around 500 meters. Further up, Castanopsis acuminatissima may form dense, almost monospecific forests on ridge crests and upper slopes from 500 meters upwards. Aside from these examples, single species stands are unusual in the tropical rainforest but characteristic of some New Guinea mountain zones, where one finds the Nothofagus forests.
The vegetation of higher elevations is generally characterized by a canopy lower than the rainforest below. The smaller girth trees here have less buttressing are more even in height, at between 20 and 30 meters. Branches grow much lower on the trunks. Species numbers diminish drastically.
Many lowland families such as Sapotaceae, Dipterocarpaceae, Annonaceae, Bombacaceae and Barringtoniaceae have but with few representatives, if any at all in the highlands. Prominence gives way to temperate families: Fagaceae, Lauraceae, Elaeocarpuaceae, Cunoniaceae and Coniferae. The shrub layer becomes denser and highly variable. Palms and climbing rattans become rare. Woody lianas are also less abundant. Scrambling bamboo (Nastus) is widespread but rarely dense except at openings in the canopy. Pteridophytes and mosses are richer and more numerous with altitude and tree ferns such as Cyathea and Dicksonia are often more conspicuous in the shrub layer and the subcanopy. Pandans are common. Epiphytic mosses, ferns and orchids are richly developed and tend to become more abundant with increasing altitude. This is a complex mosaic of community-types.
1. Lower montane forests (to 1000m)
The vegetation of New Guinea starts to become more interesting with altitude, with the appearance of more and more endemics. The mountains are divided into several forests zones, depending on the dominant trees and plants. In the lower montane areas, the plants here are almost all broad-leaved. Starting around 600 meters, we have the species Castanopsis acuminatissima, along with the New Guinea true oak genus, Lithocarpus. There are also many tree ferns starting here, mostly of the genus Cyathea. Terrestrial orchids and epiphytes also give this forest a distinctive physiognomy. The main genera in this zone are the Castanopsis, Lithocarpus, Araucaria and Agathis.
Starting at about the same elevation as the oaks, we also have two distinct descendants of old Gondwanaland trees, found only in the southern hemisphere and valuable for the timber trade: the hoop pine, Araucaria cunninghamii (found only in Australia and New Guinea) and the klinkii pine, A. hunsteinii (a PNG endemic, not found in Irian) respectively. These species grow from about 500 meters up to some 2450 meters and can occasionally tower to 70 meters (40 meters is more common), dominating the closed canopy of broad-leaved species below. Another conifer, Podocarpus amarus, makes an occasional appearance. The family Auraucariaceae form part of the Coniferales (cone-bearing) plants and is placed by botanists among the most ancient and phylogenetically primitive of world’s surviving conifers. It is held in superstition by some of the natives PNG. Most gymnosperms are absent from wet lowland tropical environments. The native hoop pine is held in special respect by some of the Papuans in PNG for what has been termed ‘religious and superstitious’ reasons. It is found in discontinuous area in the central highlands and in the Own Stanley Range in PNG.
Towards the upper limits of this zone, Elaeocarpus and Sloanea (both of the Elaeocarpaceae family) become prominent and number of species in canopy decreases. The Lauraceae family here is represented by Cryptocarya and Litsea, with the genera Syzygium, Callophyllum, Elmerrilla and Weinmannia also present. Agathis can be a local dominant, mostly in small stands.
More than any other ecosystem, the lower montane zone suffers from great environmental impact by man due to its suitability for traditional subsistence agriculture and, recently, for logging.
Depending on local conditions and the describing botanist’s particular criteria, the gradual transition to the midmontane vegetation takes place at altitudes starting as low as 1000 meters to a zone running from 1800 to 2200 meters.
2. Mid-montane forests (1000 to 3000m)
The species at these elevations (1200 to about 2500 meters) are quite distinct from those of the lowlands, The main characteristic plants here are lichens and, most of all, epiphytic mosses. In fact, Johns writes that ‘the greatest diversity of the moss flora comes in this zone, much greater than the upper montane forest which is often called “moss” forest.’. The dominant trees are the Nothofagus, Dipterocarps and cone-bearing trees. Nothofagus tends to grow gregariously, forming relatively pure stands on sites such as ridge crests and upper slopes but this tree is rarely important above 2700m. There are also mixed hardwoods such from the family Cunoniaceae and the genera Syzygium, Ilex and Elaeocarpus. These form vast tracts of mixed forest.
There is a high frequency of conifers here, characteristic of the zone: several species of Podocarpus, along with the genera of Dacrycarpus, Dacrydium, Falcatifolium, Papuacedrus and Phyllocladus. Conifers assume increasing importance above 2400m and dominate the canopy and emergent tree layers.
Tree ferns are abundant here, along with the climbing bamboo, Nastus productus, in disturbed areas. Perhaps the most remarkable trees in this area (and the lower montane forests too) are the Nothofagus. It is numerically one of the most common trees on the island, forming some 10 to 20 per cent of the canopy in lower to mid montane elevations. Prior to the wide-spread use of steel axes on the island, Nothofagus was largely left alone due to its hardness. Now that no longer matters and the trees are cut as timber under the trade name of New Guinea Beech.
This genus of tree is only known from the southern hemisphere, where it is quite wide-spread: South America, all through the Pacific Basin, New Zealand and New Guinea. The tree grows in both tropical and temperate climates. All this adds up to the fact that it was probably wide-spread in Gondwanaland during the Cretaceous, and rafted its way across the Pacific as the land bodies moved further and further apart. So the genus is an ancient one which has successfully extended its range from a temperate origin to the humid tropics and on to the cool humid montane setting. This adaptation involved not only a climatic one but also various soils and biota in different ecosystems.
Common subcanopy and shrubs include Cryptocarya, Cinnamomum and Pandanus. At higher altitudes, this same layer shows Drimys and Carpodetus. Some members of the family Ericaceae (Rhododendron, Vaccinium) are common, especially as epiphytes.
3. Upper montane forest (3000 to 4000m)
Popularly called moss forest or cloud forest, to scientists this forest is a Phyllocladus-Xanthomyrtus association, for the two tree main genera, usually 20 to 25 meters high. Most of the trees in this forest are gnarled, crooked and stunted, except for the emergent conifers such as Papuacedrus, Dacrycarpus, Podocarpus brassii and Polycladus, along with Schefflera. The lower layer of much-branched trees with thin, flat stems and twiggly crowns, often forms a dense canopy reaching seven to fifteen meters. The shrub layer is open. Mosses and epiphytic orchids are less common than in the mid-montane zone.
The undergrowth is profuse with many tree saplings and tangled masses of roots.
This is the zone (along with the subalpine) which holds the most species of the Ericaceae family, fairly well known thanks to their conspicuous flowers - especially the rhododendrons. The family occurs mostly from the Arctic to warm-temperate climes in Africa and the Americas. In Malesia, it occurs mostly on mountains nearing the equator, in the more woody, open vegetation, from 1000 to 3700 meters. Its epiphytic habit is associated with the tropics only. In New Guinea, there are six genera from this family, with some 400 species, making it one of the most diverse woody families of this vegetation. While none of the six genera are restricted to New Guinea, all but three of the many species are only found on this island.
Towards the tree line, the trees are shrub-like and the forest either shades into a dense shrubbery in which Ericaceae are predominant or opens out to form a low woodland with the fire-resistant Dacrycarpus compactus at times emergent to 15 meters, even near the tree limit.
4. Subalpine and Alpine zone
As the altitude increases, the vegetation is dominated by an increasingly smaller number of species. There is a great deal of variation in local distributions as the higher elevations are affected by several factors to different degrees: temperature, rainfall, wind, base soil type and man’s burning activities for hunting. Where there is still closed forest, the canopy seldom surpasses 10 meters, but emergents top this by five meters or so. Many of the trees at this elevation branch near their bases. Bryophytes dominate ground flora, with epiphytes and climbing shrubs less common with the exception of the epiphytic fern, Hymenophylum fosteri. As one approaches the forest limit (3900 meters in PNG, 4170 meters in Irian), the dominant plant families are the Ericaceae (Rhododendron spp. and Dimorphanthera spp.) and Epacridaceae (Trochocarpa spp. and Rapanea spp.)
Beyond the tree line, the tallest plants are the tree ferns of the genus Cyathea. Here we find grasslands with bog and fern associations. Acid bogs develop when the ground water is stagnant, with hummock plants and shrubs as the prominent plants. With moving ground water the milieu is less acidic and ferns thrive. At the base of cliffs, with free flowing water, we find the plants Danthonia archboldii and Gaultheria mundula along the stream banks.
Above tree line, show shrub or herbaceous communities predominate. Common shrubs include the heaths Ericaceae (Vaccinium, Rhododendron, Dimorphanthera, Gaultheria) and Epacridaceae (Styphelia, Trochocarpa) along with Olearia, Coprosma and Gonocarpus. Mid-height tussock grasslands Deschampsia klossii a common dominant gives way to low grassland in which dwarf grasses as Poa, Festuca and Danthonia predominate and mountain herbs are common. Cycad-like ferns (Cyathea atrox and C. gleichenioides) are locally abundant in grasslands. Sedges important on wetter sites and commonly predominate on bogs and fens.
With increasing altitude, lichens, bryophytes and mountain herbs assume greater significance; on summits, above 4200 meters, communities of small, compact herbs, including Ranuculus, Gentiana, Eriocaulon, Potentilla, Poa and Parahebe and mats of bryophytes occur on the frost-sorted soils of the slopes. In all the high elevation tussock grasslands, Deschampsia klossii dominates, often in association with Hierochloe redolens. In deep, moisture-retaining soils, we find heath vegetation, mosses, bog species and dwarf shrubs. At the highest levels, rock basins hold wet tundra systems.
History and evolution of high altitude flora
The first elevations in what is now New Guinea did not start until some 30 million years ago, quite recent in geological history. The higher elevations happened much later, in Tertiary times. Then the whole earth experienced a cooler climate, including glaciations when the uppermost vegetation was about 700 meters lower than at present. Due to the cool climate, plant elements from Gondwaland could spread to New Guinea. These are now found mainly in the mountain forests, where they dominate both numerically and structurally. The elements include the families Cunoniaceae, Podocarpaceae and Winteraceae, with dominant genera such as Helicia, Pittosporum and the champion, Nothofagus. Their species are often endemic to the island.
While the dry areas along the center and south-east of New Guinea are dominated by Australian flora such as Eucalyptus, the lowland rain forests are of mainland Asian origins. For the subalpine and alpine ecosystems, the grass affinities are both Australian and Asian. With few endemic grasses there, it is most likely that the immigrations were recent: only 4 per cent of the genera and 74 per cent of the species are restricted to the island. This makes perfect sense if we remember that the date of the higher elevations combined with cold climate has taken place only during the past few (2 to 5) million years. Cold-adapted flora had to wait until then to colonize the new, high altitude ecosystem. High equatorial mountains in general have more in common, plant-wise, with temperate zone mountains than with the flora in the adjacent lowlands. This is especially true in New Guinea where the flora of high elevations show a marked degree of affinities with that of the mountains of Australia and Asia. But these temperate-climate adjusted plants had to make some evolutionary changes in New Guinea: they had to adapt to diurnal, rather than seasonal temperature variations, with the year-long possibility of frost and the lack of a marked warmer season for growth.
If we survey the plants above 3000 meters and exclude epiphytes, the division between woody and herbaceous species is 46 to 54 per cent in favor of the grasses. Both types have their maximum numbers around a mid-point of 3250 meters. Below this level, there are more woody species, above it, more herbaceous ones. The woody plants, less capable to migrate than grasses, show 9 per cent generic endemicity and for the species the number shoots up to 92 per cent. Nearly all woody plants in the high zone belong to the Ericaceae family, which originated in Eurasia. The family includes the rhododendrons, with hundreds of species, ranging from sea level to the alpine.
With man interfering with nature, essentially by burning for hunting, the flora undergoes drastic changes, with grasslands becoming much more extensive. Only a few trees, almost exclusively conifers, survive the burning. This isolated trees of the genus Dacrycarpus (mostly Dacrycarpus compactus) survive and, surrounded by grasses, mark the former extend of the forest.
Pandanus for nuts and leaves
The Pandanaceae family of monocots make up a significant element of New Guinea’s flora, with 123 species which are often conspicuous and characteristic. Many have light colored trunks and prop roots. The leaves usually form a spiral, thus the popular name of ‘screw pines’. It is one of the first trees easily identified by a novice, budding botanist. The plant is a primitive one but its wide colonization shows its high degree of success and the family is probably still undergoing evolutionary changes. There are only three genera and much of the evolution of these has taken place in New Guinea. These three genera have all survived here, so the island represents both an area of relictual survival as well as change and diversity.
Identification of various genera and species usually rests on the structure of the drupe or phalange of the fruit. Most taxonomic work has been done with female plants, as males are few and some species develop only females: these are ‘apomictic’, meaning the unfertilized carpels (female reproductive organ in flowers) will still develop to form seeds. Male plants tend to have more branches and smaller leaves. The largest leaves are produced by the juvenile plants with a size up to three times that of the adult. The juvenile cephalia also tends to be larger, with more dupes or phalanges. Many species have thick, leathery leaves with the midrib usually folded sharply downwards and resilient to decay.
The genus Sararanga has but two species, one in the Philippines and the other, Sararanga sinuosa found only in north-east Irian. This last species has the most archaic features in the family. The tree is palm-like, with a single head, no evident prop roots, with massive branching and plenty of many-seeded fleshy berries. It is found in the lowlands near the coast and is quite tolerant of limestone. The plant often occurs in exposed aggregations on beaches and savannahs, as the canopy in lowland swamps, in riverine or gallery forest or in montane forests. Where this species forms pure stands, the ground can support very little other vegetation due to the thick layer of fallen leaves. This is also true for Pandanus groves.
The genus Freycinetia is one with climbing stems seen on forest trunks, or as an erect shrub. There are some 180 species in the genus, of which at least 50 are found in New Guinea.
Most attention focuses on the Pandanus genus as this is the one most used by man. Estimates as to the total number of species within this genus vary from 500 to over 900 (taxonomic lumpers versus splitters). In New Guinea, there is agreement at some 63 to 66 species, with the possibility that there may be others lurking out there, waiting for scientific attention. Of the identified species, 50 or about 80% are endemic.
The genus Pandanus is an isolated one, traditionally associated with palms, the only other major arborescent group of Monocotyledons. The palm Nypa fructicans, with the longest fossil record, grows fruit very much like pandanus. In spite of its many archaic features, the genus has been and remains highly successful, having retained its cohesiveness over just about the whole Age of the Angiosperms.
Some pandanus species are cultivated for their fruit or their leaves, but most fruit and leaves are harvested from wild plants. The species receiving most of man’s attention for its edible nuts, Pandanus jiulianetti, grows in the upper montane zone, where P. brosimos is also found and has edible nuts as well. Some botanists say that while a few of these two pandanus species are found at 2000 meters, most are considerably higher, above 3000 meters. Others state that it is most abundant between 1500 and 2800 meters. Some scientists also think that the two might be a single species. This upper montane area is also home to the P. antaresensis, with its roots, bark and drupe shells used in traditional medicine for headaches, diarrhea and breathing difficulties. The leaves are also used for thatching.
P. jiulianetti may be cultivated individually or in groves. It is unknown in the wild. The species has many varieties, a result of many millennia of human intervention. Propagation by cuttings produces rapidly maturing in four to five years, while by seed maturation stretches to eight to ten years. The species can produce two, and occasionally three, harvest a year, as opposed to P. brosimos, which produces fruit but once a year, albeit with a faster rate of ripening. Both species are easily identified due to their height as compared with the surrounding vegetation. Both species produce fruit at the same time. These are massive subglobose heads composed of numerous large singe-seeded drupes; the large and fat-rich endosperm is the edible part. The nuts not consumed on the spot are dried over smoldering fires for storage, lasting for weeks or even to six months. They are one of the most important food plants in the high montane zone. Both are endemic to New Guinea. In PNG the two species are called karuka in pidgin English. In Irian, different groups have many names for these two essential trees. Both can produce ‘karuka madness’, a hysterical atoxic state due to the chemical Dimethytriptamine (DMT) in the nuts. P. brosimos, the most favored on pandanus nuts, produces fruit with thinner shells which can be cracked with (strong, healthy) teeth.
Another species, also cultivated and gathered from the wild as well, P. conoideus (marita in pidgin) is found from close to sea level to 2000 meters. Most of the plants are sterile and thus propagated by cuttings. The species is found mostly in New Guinea, along with the Bismarck Archipelago and might be present in the east Moluccas as well. The fruit’s long, angular cone-like pedicarp is rich bright red or yellow and contains similarly colored oil which is released on cooking (often baking): the solid fat liquefies. The fruit is then mashed and the oil squeezed out by hand to form a rich oleaginous mush from which fibers and endocarps are removed. The resulting mash is of mild or insipid, and it is used as a fat-rich sauce for enhancing starchy foods, mostly tubers. The whole fruit or the mash is often sold in PNG. P. macgregorii also produces an edible fruit, cooked and eaten similarly to P. conoideus. It could be that this species replaces P. conoideus at low altitudes...or that a single variable, locally called marita, is covered by these two scientific names. P. conoideus is cultivated throughout Moluccas and New Guinea. Another species is much more wide spread: P. amaryllifolius is cultivated for its fragrant leaves and staminate inflorescences (for eating). This is a recent introduction to New Guinea. Used as flavoring agent in many parts of south-east Asia for nasi lemak, cakes and desserts, it is commonly referred to as just ‘pandan’.
Several other species of pandanus are widely used for their tough, leathery leaves resistant to decay, in making roof thatch, house partitions and coarse mats. Several species fall into this category, with P. tectorius as the most important, variable and widespread one. It is planted as well as harvested from the wild. In some areas, P. dubius is preferred for roof thatching. Both of these species are wide-spread in south-east Asia and through the Pacific. The most obvious one, P. tectorius, is often seen on beaches, on rocky coasts as well as a fair distance inland in some mangrove areas, swamps or along small streams and estuaries in the flat areas. It can grow on a limestone as well as a basalt substrate, up to some 500 meters elevation. Other beach and estuarine pandans include P. dubius and P. polycephalus. The latter species is found in western Indonesia as well as New Guinea.
Other common lowland pandanus species include P. lauterbachii, often seen in the lowlands, usually in a fresh water or estuary swamps. This species is also found in north Queensland. It has rounded, its roots are not of the more common prop type but spine-like. The most common pandanus along rivers, P. leptocarpus, follows the inside curves of some riverbanks as monospecific stands inland to around the 50 meter elevation mark. The plant produces hundreds of thin drupes. It is much branched and its lower stem lays close to the ground, with numerous sucker shoots up to 15 meters long. This endemic species produces a green fruit, colored orange-red below, which shows its waterside adoption: the ripe fruit must fall into water to spread and propagate. Its fruit is eaten by fish, a well know fact to local fishermen. [one reference, in Gressitt: B. Stone - P. aquaticus produces a fruit which attracts white cockatoos. Cassowaries can crack the nuts of many a fallen pandanus, also eaten by turtles and other animals.] The main riverside and gallery forest pandans are P. leptocarpus and P. pendulinus, both New Guinea endemics. The riverside P. polycephalus, a branching shrub to 4 meters height, shows many bright red drupes when fruiting.
The Fagaceae, the Podocarpaceae and Araucariaceae families have some very special representatives in New Guinea. As the eucalypts define Australia’s flora, thus the genus Nothofagus represents New Guinea. This genus is not endemic to New Guinea, but it is found in profusion here. In fact, where else it is found which adds holds special interest. The dispersal of Nothofagus is by seed which can not travel much more than a few kilometers. Yet it is found in South America, New Zealand, New Caledonia as well as the Australian region. It took botanists a while to figure out just why, but now they (and we) know: the genus had wide distribution in Gondwanaland during the Cretaceous Period. Then came plate tectonics: the splitting up of this super-continent as and effect of the spreading ocean floor, leading to isolated land masses slowly taking their present geographical locations. Nothofagus was already present on the various land masses before Gondwanaland split into its component elements.
The same continental drift that placed South America way beyond the Nothofagus seed dispersal range also brought New Guinea fairly close to south-east Asia. Not close enough to our genus to reach with its seeds, but close enough for many other genera from the west to reach New Guinea. Better adapted to lowland, tropical conditions, by late Tertiary times, these new immigrants pushed Gondwanic genera such as Nothofagus, up into the mid-montane area where they are found today. While the various species of the genus are found in different altitude ranges, all thrive in areas of high rainfall and cloudiness which reduces light penetration by as much as 70 per cent. Nothofagus reaches elevations of around 3100 meters in New Guinea, well below the tree line. (The altitude of the tree line varies according to several factors. In the Puncak Jaya area of Irian, it is at 4170 meters.) The genus grows in a diverse range of substrates, ranging from ultrabasic to acidic, ingenous to metamorphic, calcareous to siliceous soils. However, these trees grow the most rapidly on volcanic substrates while their growth becomes stunted on shallow soils covering limestone. Before leaving this most characteristic of New Guinea tree, let us add that its timber is hard, durable and valuable in the lumber industry. The Papuans use these abundant trees for house construction, cooking, tools and heating.
The Nothofagus genus belong to the Fagaceae family which groups a total of seven genera and some 700 species. In Malesia, we find five genera and about 180 species. Only three genera are found in New Guinea. Lithocarpus, with a single species, Castanopsis acuminatissima, grows below 1500 meters, with some pure stands on ridges. The Lithocarpus genus, with nine species in New Guinea, is sometimes a co-dominant in the mid-montane forest, along with Araucaria, Castanopsis and Nothofagus. Some of the 13 Nothofagus species are found between a low range of 750 to 1000 meters to a high one of 3100 meters. These trees are frequently dominant in the range where some 90 per cent of the genus is located: 1750 to 2800 meters.
There are five families of cone-bearing trees in Malesia, with three occurring naturally in New Guinea: Araucariaceae, Cupressaceae and Podocarpaceae. While no Pinaceae are native to the island, two valuable species have been planted quite extensively in the eastern part of the island: Pinus kesiya and Pinus merkusii. The family Araucariaceae, with two genera and five species in Irian, holds the wide-spread and well known timber trees, Agathis and Araucaria. The Cuprassaceae family groups 19 genera, of which only one is found in Malesia. This is Libocedrus, with seven species. Only Libocedrus papuana occurs in Irian. The Family Podocarpaceae, with 13 genera and some 172 species, has seven genera and 31 species in Irian. Aside from the relatively well-known Podocarpus (14 species), we have Dacrycarpus (5 species), Dacrydium (6 species), Falcatifolium (2 species), Nageia (2 species), Phyllocladus (a single species) and Prunmioitys (single species).
Special mention must be made here of the New Guinea bamboos. This plant belongs to the Graminaceae family of grasses and hold the rank of the most versatile in this group, or, indeed in any group. World-wide, there are some 1000 bamboo species, divided into 80 genera. In South-East Asia, we have about 200 species grouped into 20 genera. New Guinea has but four genera, with 26 species (Holttum, 1963) with all but one either endemic or found only on the island and close-by. In Malesia, the most wide-spread genera are Bambusa (37 species), Schizostachyum (about 30 species), Dendrocalamus (29 species), Gigantochloa (24 species), Nastus (15 species), and Racemobambos (some 16 species). (Prosea, #7) On the species level, Bambusa vulgaris, an often planted pan-tropical is the only species non-endemic to New Guinea and vicinity. It has adapted to many kinds of habitats, particularly along river banks. In New Guinea, as in the rest of the tropics, bamboos most often are found in low to mid-montane elevations.
The most common of the highlands bamboos, Nastus elastus, is tall and erect, and forms a distinctive feature of the vegetation. Another member of the genus, N. hoglandii, often stands out on rain forest ridges, its preferred habitat. While slender, the species Schizostachyum lima, which ranges from the Philippines through New Guinea and the Solomons, has culm walls easily separated and reportedly used for bowstrings as its internodes can reach over one meter. Bambusa atra has had a most chequered history of name changes, as scientists identified, mis-identified and re-identified it repeatedly, going through 18 different names before bamboo experts (not many in the world) settled on its current name.
There are four genera of bamboos in New Guinea, with a total of 26 species:
1. Bambusa with the species: B. vulgaris, B. atra, B. hirsuta, B. forbesii, B. amahussana, B. macrolemma, B. solomonensis, B. fructicosa, B. riparia, B. microcephala and B. brevispicula.
2. Schizostachyum with S. lima, S. whitei, S. alopecurus and S. brachythyrsus.
3. Racemobambos: R. congesta, R. multiramosa, R. schultzei, and R. hirta.
4. Nastus: N. hooglandii, N. schlechteri, N. longispicula, N. obtusus, N. rudimentifer, N. productus and N. elastus. (Holttum, 1963)
A distinction can be made between clump-forming, single stemmed and climbing bamboos. The clump-forming (or tufted) bamboos, represented by the genera Bambusa, Schizostachyum, Gigantochloa and Dendrocalamus are predominant in the tropics, while non-clumping types are found in temperate zones. The rhizomes (underground stems) are of great importance because there is no central trunk as in trees, and the rhizome becomes the foundation of the plant. Culms are produced annually from the younger rhizomes. Many bamboo plants of the same species flower simultaneously, at intervals of 20 to 120 years, and then all culms die, to be replaced by seedlings.
Anyone with a modicum of familiarity with life in the tropics knows how important bamboos are to the local cultures. ‘No plant is known in the tropical zone which could supply to man so many technical advantages as the bamboo. The strength of their culms, their straightness, smoothness, lightness combined with hardness and greater hollowness; the facility and regularity with which they can be split; the different sizes, various lengths and thicknesses of their joints make them suitable for numerous purposes to serve which other material would require much labor and preparation.’ Kurz, 1876, quoted in Prosea #7). In recent years bamboos have entered the highly competitive world market in the form of pulp for paper, parquet, plybamboo, and as a canned vegetable. For centuries, the Chinese have made paper from bamboo.
‘There is hardly any rival in the plant kingdom with regard to the variety of taxa, habitat, distribution and uses. Since time immemorial, this tall, perennial and handsome grass has been linked to human livelihood, fulfilling our needs of food, shelter, furniture, transportation and entertainment.’ A Chinese philosopher aptly said, ‘A diet without meat makes one emaciated. A living environment without bamboo makes one vulgar. I would rather eat no meat than live without bamboo’. (Prosea #7)
Unlike the other, slender members of its genus, B. vulgaris grows to a large size, with strong, thick-walled culms. It is the most suitable of bamboos for construction. While most grasses’ stems are solid and flexible, bamboos have hollow, incredibly strong culms (stems). So strong that in some places in Asia, the culms are used to reinforce concrete structures. B. vulgaris is also used for fish traps and spear shafts. Split on one side, then flattened (and thus cracked vertically) into still strand-connected parallel strips, bamboo is woven together to fashion house walls, partitions and ceilings. In many coastal houses in New Guinea, we have seen elaborate house walls, made of culms split into long, thin strips which are then plaited together into various motifs, often incorporating a subtle color contrast. World-famous furniture is made with species such as Gigantochloa atroviolacea and Dendrocalamus asper whose culms are straight and smooth.
In New Guinea, as well as in just about all its tropical range, bamboo shoots (called rebung in Indonesian) are eaten as a vegetable. In the western part of the island, the species Racemobambos and Nastus are used in some areas as arrowheads, with the shafts fashioned from the straight, thin culms of Schizostachyum species. Cut the right way, bamboo knives can be incredibly sharp. At Bunlap village where I lived in the New Hebrides (now Vanuatu), the local ‘barber’ cut my hair several times with a bamboo sliver. Running out of blades, I shaved several times (not too happily) with bits of bamboo. At the same village I saw a circumcision ritual where bamboo knives were used to cut the foreskin of the young boys. This method is also a common practice among the Muslims of Indonesia and Malaysia. Bamboo knives are also used to cut the umbilical cord in many areas, including Japan, China and India. On the north coast of New Guinea, bamboo is often used as the main single or double outrigger.
While in New Guinea we have seen bamboo flutes, elsewhere in Indonesia idiophones (percussion instruments) are made from bamboo, including the famous Sundanese klungkung orchestras. Stringed musical instruments are made from bamboo as well, not to mention an endless variety of handicrafts. Bamboo culms are often used for cooking vegetables, meat and rice. The famous lemang, made from glutinous rice and coconut milk, is cooked in bamboo tubes. Both the Kamoro and the Asmat of the south coast of New Guinea use thin bamboo tubes to hold a lime powder, flung in the air to honor spirits during rituals. The Kamoro also use bamboo for cooking during rituals.
Man and plants in New Guinea
Everywhere in the world, since mankind’s earliest history, plants have been the basic sustenance for survival. When the Papuans’ ancestors first migrated to New Guinea, they found a vegetation complex which contained many unknown species, as well as some they must have been familiar with during their migration from the west. Throughout the tens of thousands of years that mankind has lived on this island, various uses have been found for many plants. One scientist list 650 plants (in 134 families and 378 genera) used by Papuans, from medicine to cordage, from canoe making to carvings. And, of course, for food. About 200 plants are used for food today in New Guinea, with some 65 cultivated species and 158 mainly gathered from the wild. Some of these plants fall into both the cultivated and the gathered categories. Food supplies determine population densities, and the island’s various ecosystems support anywhere from two to two hundred inhabitants per square kilometer.
Of course Papuans do not live by food alone and make widespread use of the vegetation around them for building their homes, making their carvings, ornaments, tools and weapons. With the diverse plants found in the many different eco-systems, the species use varies according to availability. One source lists 650 species (in 134 families and 378 genera) of plants used for various purposes, including 58 fungi in the highlands and 35 wild fruit trees, the latter surely an underestimate but difficult to catalogue. (Winslow, 1977).
Many government planners unfamiliar with the extensive forest resources of Irian tend to over-encourage agriculture and logging at the cost of clearing out valuable eco-systems. The forests of the island can provide much more than timber. Aside from providing food for many animals species, wild areas can provide controlled gathering of species for sale such as butterflies and beetles for export to hobbyists. Sustainable harvests are possible for many kinds of bamboo, rattan, sandalwood, massoy bark, exudates such as resins, gums and latex, tannins, copal and vatica gums. And there are literally hundreds of wild fruits, nuts and other plant foods such as vegetables. Some of the wild fruits and nuts could have commercial possibilities, including use for oil or cosmetics: pandanus, okari, pitpit, aibica, breadfruit, galip nuts among many others. Many trees have multiple-use potential. The Canarium which produces galip nuts also has bark containing oleoresins for cosmetics, a mesocarp usable for livestock feed, nut shells for fuel and a kernel, the nut, with over 70 per cent oil content, equal to the specialized oil palm. The Japanese favorite, shiitake mushroom (Lentius edodes), occurs naturally in New Guinea, along with other species highly sought in Japan and well as China: Glamerella spp, Tuber spp, Cantharellus spp, Boletus spp. The island has at least 60 species of rattan, including the giant Calamus hoolrugii favored for furniture. Various species of bamboo can also serve the same purpose. In the islands there are some 26 species in five genera, with Schizostachyum spp. and Bambusa spp. mainly in lowlands, Buergersiochloa spp. prevalent in the primary lowland rainforest with Racemobambos spp. and Nastus spp. common at higher elevations. There is plenty of potential in the vast tracts of Nypa palm, exploited elsewhere to produce alcohol, ethanol and sugar. There are plenty of coconut trees but most are too far from processing plants for economic oil production. The sago palm, with potential for making a starch flour, covers over a million hectares in PNG and probably more in Irian.
Man’s manipulation of the vegetation, incipient agriculture, goes back a long ways. Indeed, New Guinea was one of the first places on earth where agriculture began, some 10,000 years ago, as proved by archeological work in PNG. Of course, what we see today, the neat, intensive farming in many highland valley, did not occur that long ago. Indeed, the island’s most important food crop, the sweet potato (Ipomoea batatas) was not introduced from South America to New Guinea until quite recent times, perhaps in the 16th century, perhaps earlier, but definitely not more than two millenia ago. Long before that various other plants had been domesticated and grown intensively.
Man’s control of plants began with a gradual emphasis on collecting from trees such as the sago, coconut, bananas and breadfruit, along with other fruit and nut crops, and alongside yams and other local aroids. The entry of some south-east Asian species, such as non-indigenous bananas, yams and taro reinforced early horticulture, with intensive horticulture by 9000 years ago in some areas. By the time that rice was transferred out of China, some 5000 to 4000 years ago, New Guineans were practicing shifting agriculture with fallow periods in gardens with mixed crops consisting of both indigenous species such as bananas, sugar cane (Setaria, Rungia and Saccharum edule) as well as ‘imported’ ones such as taro, yams and gourds. Man soon learned that for efficient farming, burning was needed for fertilization, then after several crops were harvested, a fallow period was required, some 15 years in most ecosystems, to prevent environmental degradation which can easily result in permanent savannah vegetation. It is perhaps the cohesive social system, resulting from agriculture, which allowed most Papuans to keep their cultural identity when the technologically more advanced Austronesians spread though the Indonesian archipelago and wiped out whatever peoples and life-styles existed in the west.
Papuans learned long ago and continue to exploit wild plants for an important part of their diet, no matter in which ecosystem they live. The lowland rainforests and swamps are the richest in usable wild foods. The fruit and nut crops here include Canarium, Castanopsis, Pangium, Barringtonia, Inocarpus, Pandanus, Pometia, Terminalia and Cocos nucifera. The swampy areas are rich in edible stems and tubers such as Alocasia and Cyrtosperma. Various palms in this zone also provide edible nuts, along with ‘heart cabbage’, the edible center of young plants.
Some of these crucial plant resources exist at a great altitude range: Artocarpus, Musa, Pandanus, Castanopsis and some palms. There are edible ferns of different species at almost all altitudes, along with wild sugar cane, Saccharum spp., wild gingers and yams. The fact that bananas and Artocarpus (breadfruit) produce fruit without a season makes them even more important. The main food plants in the mountain forests, aside from those listed above, belong to the following genera: Sterculia, Syzygium, Finschia, Elaeocarpus, and Chisocheton.
While there are plentiful food resources in the lowlands and swamp areas, the population is low due to malaria: two to four persons per square kilometer. There are many food plants but a few provide for just about all the material needs: coconuts, sago, pandanus, bananas and bamboos.
The most widespread and long established banana in Melanesia is Musa sapientum. Most cultivated bananas have high starch content and must be cooked before consumption. These occur in the wild from India to New Guinea. In villages of acute land shortages they can become the staple due to their perennial nature, plus the fact that they require no fallow and little labor input. Bananas have become the dominant staple in some grassland regions. The bananas with high sugar content eaten mostly raw are recent introductions for both local and foreign tastes.
Sago, from the palm Metroxylon sagu, provide the basic staple food for many coastal populations. The trunk of these trees turns to pure starch just before flowering. This starch can be extracted relatively easily, with a few days’ work enough to produce food for a month. Sago palms can also provide an important source of additional protein: the sago grub, Rhychophorus ferrugineus, are harvested for consumption, raw or roasted. Other palm weevils are useless pests: Rhinchophorus bilineatus, Ocyctes centaurus and Ocryctes rhinoceros which damage coconut trees.
Moving in from the coast, shifting agriculturists exploit the savannah and grassland zones, with populations ranging from 16 to 30 per km2. With less rainfall, they concentrate on crops which survive dry periods: bananas and yams (Discorea spp.) being the staples in many seasonally dry areas. Cassava, Manihot esculenta, grows well as a staple where the soils are the poorest and driest. The shifting agriculturists in the tropical rain forest have smaller population concentrations: 8 to 16 per km2. Here the main crop is taro, Colocasia esculenta, with bananas and sweet potatoes as the main supplements. The main wild fruit and nuts in this area are from the genera Canarium, Pangium, Pometia, Spondias, and Terminalia.
The highest population concentrations in Papua are in the highlands, among some of the world’s most efficient traditional agriculturists. Nearly 40 per cent of Papua’s population lives in the highland valleys, at elevations ranging from 1400 to 2700 meters, and with concentrations of up to 200 souls per km2. Most of this profusion of humanity is thanks to Ipomoea batatas. While controversy still surrounds the date of its introduction to New Guinea, there is no question that the ‘sweet potato revolution’ opened up the highlands to high population concentrations thanks to the tuber’s growth zone which can reach as high as 2700 meters, away from the deadly malaria zones at lower elevations. In all the highlands, this is the staple, supplemented with yams, bananas, beans, sugar cane, edible pitpits (Setaria palmifolia and Saccharum edule), taro (Colocasia esculenta and Xanthosoma spp.) and many greens. Among the many wild plants used, the pandanus heads the list (see above).
The highlanders successful agriculture is based on complex ground preparation, water flow control, and the tendency towards polyculture of many species or at least many varieties of a single species which acts to protect agrosystems from heavy losses to pests and pathogens. Other good practices for controlling pests include burning, crop rotation, multicropping and shading. Sometimes fields are abandonned after two to three years due to pest buildup but most highlands agriculture is more or less continuous cropping with controlled short or long term fallows.
IV. Origins of New Guinea’s animals
Considering birds of paradise and marsupials, New Guinea’s most famous citizens, it would seem logical to assume that Australia was the island’s major source of animals. But the conclusion is wrong. When we take in the totality of the animals in New Guinea, it becomes obvious that the great majority originally came from south-east Asia. But looking at a map, this does not seem to make sense. New Guinea and Australia seem so close to each other and we know that the island formed a part of the Australian land mass in the past and land connections existed, on and off, up to some 8,000 to 10,000 years ago. No land bridges ever existed all the way to south-east Asia, nor even to the easternmost islands of present day Indonesia, except for the Aru Archipelago. Even during the height of the recent Ice Ages, when sea levels dropped by as much as 150 meters, sea passages dozens of kilometers wide prevented man or beast from strolling to New Guinea from the west.
But if man could travel to the island by canoe, why could animals not make their way across the water as well? Some did, and some did not. The most obvious, larger animals such as tigers and elephants, did not even make it across the Bali-Lombok strait. This fact was noted some 150 years ago by the famous British naturalist, Alfred Wallace. The fact that some elements could not cross over water between Asia and the Indonesian Islands let to a north-south line, named after Wallace, which supposedly separates the Asian from the Australian animals. But while the Wallace Line still maintains some of its basic validity as far as some animal groups are concerned, there are many other groups which did cross the line and made their way to New Guinea, with some reaching Australia as well.
When we take a close look at the land connection between Australia and New Guinea, the nature of the ‘bridge’ must be taken into account, along with the climate and vegetation on either side. During the times that the Arafura Sea dried up, the former sea bottom was easy to cross for man, the most clever and adaptable of animals. But the dry, scrub vegetation proved to be insurmountable for most other animals. And two very different eco-systems existed in much of southern New Guinea and northern Australia. The former was a tropical rain forest while the latter was a dry, near-desert. Many animal groups found it difficult if not impossible to cross even at the present day Torres Strait, north of the Cape York Peninsula which forms an extension to northern Queensland where rain forests existed and still do to this day. During the Ice Ages of the Pleistocene, the climate in New Guinea became more arid, isolating the rainforest into patches separated by savannah grasslands: this stimulate speciation among both the flora and the fauna for the sake of survival in a different ecology. The rise of the mountains at this time, with greatly modified temperatures and rainfall, also made a great contribution to the diversity of New Guinea life by forcing species to evolve in order to adapt to the new conditions.
The climate-dependent vegetation formed the greatest barrier to the infusion of animals from Australia to New Guinea. From Asia, the stretches of sea water prevented fresh water fauna and most terrestrial mammals, except for rodents, from reaching the island. But this did not stop hordes of insects, bats and other animals. Today’s insects of New Guinea are mostly of oriental descent. When all the species are counted up, there are far more from the west than the south. Looking at the total numbers of animals species in New Guinea, terrestrial vertebrates make up less then one per cent. And in the category of mammals, New Guinea lacks nine groups (orders) found in south-east Asia, along with the larger marsupial herbivores and carnivores of Australia. In an unusual arrangement, some of the mammal niches elsewhere have been taken over by birds or other animals. After the extinction of the ‘Tasmanian’ wolf, the largest remaining indigenous mammal carnivore is no bigger than a smallish domestic cat.
Important climatic and ecological barriers everywhere are more significant than land connections. While the Torres Strait allowed some interchange of biota, it also acted as a tough filter, especially to Australia’s dry-adapted animals and plants. The origins of New Guinea animals is further complicated by the island’s geological history whereby islands, with animals which evolved in isolation, were incorporated into New Guinea. Barriers, both of the filtering and semi-filtering kind, surround this large land mass. The bottom line is that is was the plants which determined what animals could move into New Guinea.
While the availability of the right kind plant food was the crucial factor, the animals’ varying ability to disperse and colonize must also be considered. Most mammals are poor dispersers over water but tend to be adaptable colonizers. However, bats (mammals) are good at dispersing between island chairs, as are insects and some rodents, so these had no problems immigrating to New Guinea. However, when they tried to move further south, the dry Australian savannah eco-system stopped most of them cold. Thus the spectacularly high diversity of life in New Guinea, in spite of its young geological age, is much more conspicuous for insects and plants, rather than the better known vertebrates.
There are many groups of animals, most in fact, which we do not cover in this study of biodiversity. Many are marine creatures, found in other places. Others have not received sufficient scientific study in New Guinea. We deal only with three main phyla: arthropods (insects and crustaceans), mollusks (gastropods and bivalves) and vertebrates (fishes, amphibians, reptiles, birds and mammals).
Arthropods are the dominant phylum on our planet, with well over one million species, of which 95% are insects (and two thirds of these are beetles). All the animals in the phylum have three major body sections: a head, a thorax and an abdomen. The body is covered with a hard outer skeleton (exoskeleton) for protection. Another characteristic of the group is reflected in the meaning of the phylum’s name: arthropod means joint-footed. Aside from the Class Insecta, the phylum also includes the Class Crustacea, marine or fresh water arthropods: shrimp and crayfish as well as crabs (some of the latter are also land-dwellers). There are some 26,000 described species of crustaceans, ranging in size from the microscopic krill (whale food) to the giant Japanese spider crab with an awe-inspiring claw span of up to 3.6 meters.
The phylum of the vertebrates (with a backbone), generally the most highly evolved animals, include our own species in the class Mammalia. Other members of the elite vertebrates are in the class Chondrichthyes (fishes with skeletons of cartilage: sharks and rays), class Osteichthyes (all other fishes, with bone skeletons), Class Amphibia (frogs and salamanders), Class Reptilia (turtles, snakes, lizards and crocodiles), and Class Aves (birds).
In summary, New Guinea’s fauna included 644 species of breeding birds and 214 species of breeding mammals in the warm-blooded category, with the cold-blooded beasts totaling 784 species, including 282 freshwater fishes, along with 505 amphibians and reptiles, of which some 46 per cent are endemic to the island. (Beehler, 1993) A quarter of a century ago, the total number of birds for New Guinea (including the Bismarck Archipelago and the Solomons) reached 860 species, as compared to Australia’s 660, the Americas’ 800 and 1100 for the whole of Eurasia. (Winslow, 1977). However, some of these tallies date back over a decade or more, so undoubtedly the numbers have all increased by now.
The mollusks: coiled or hinged
The name of the phylum Mollusca comes from Latin and means ‘soft-bodied’. They form the second largest phylum after the arthropods, with about 128,000 species. Most cover their soft bodies with a hard shell made from secreted calcium carbonate. Mollusks have provided an easy animal protein food source for hominids for millions of years, due to the easy of gathering and abundance. New Guinea is no exception. The earliest pioneer Papuans undoubtedly relied on familiar mollusks until they learned about the other dietary resources of their new homeland.
The mollusk class Gastropoda includes animals with twisted shells, such as snails and triton shells. The word gastropod means ‘stomach-foot’, referring to the characteristic muscular foot fused with the head bearing the sense organs. The visceral mass is then twisted 180 degrees in relation to the head and foot. Sounds grotesque, but the resulting shells are most varied and attractive. Many gastropods are consumed in New Guinea, including the herbivorous Strombus luhuanus, sometimes called the blood mouth conch. Gastropod shells were formerly in wide-spread use in the highlands as currency, with the cowrie species Cypraea annulus and the appropriately named Cyporaea moneta being the most common. Other gastropod shells are used for decoration, including the pearl-bearing Pinctada maxima, and the cone shell, Conus leopardus in the PNG highlands. The dog whelk, Nassarius sp. finds its way to adorn human bodies in northern New Britain. New Guinea species of land snails are a diverse set, especially so in limestone areas. The calcium carbonate from the limestones can be easily absorbed, especially when the soil has a high pH, to build shells. Endemic species tend to occur around isolated limestone outcrops.
The mollusk of the class Bivalva or bivalves take their name from their hinged, two part shells. These include the oysters, scallops, clams and mussels, most of which are filter-feeders. Although now greatly reduced in numbers, one can still find giant clams in the coastal waters of Irian. Growing to 1.5 meters in length and weighing up to 200 kg. or more, these animals are shallow water species. This is because of the symbiotic zooxenthellae living in the clam's tissue, giving an intense blue-mottled patterns to the flesh. The shell is wide open in the daytime to allow the zooxenthellae to catch sunlight and photosynthesize. Two large siphons, one inhalant, the other for exhaling the filtered water, also identify the Tridacna gigas, along with smaller members of the genus. Easy to spot for divers, the giant clams are also an easy prey for commercial divers. The Taiwanese seek its flesh as a gastronomic delicacy while the shells used to be ground up in Java to make bathroom tiles. Today there are not enough of these giant clams to keep the industry going.
Many species of bivalves are consumed by coastal Papuans but we have not been able to obtain the results of any research in this field outside the Timika area in Irian Jaya (see below). We have only one reference to a bivalve species consumed in PNG, Anadara antiquata, a shallow marine filter-feeding bivalve, usually buries in areas of sea grass on the intertidal zone of coral reef platforms. (Winslow, 1977).
Aside from Freeport’ on-going studies of estuarine mollusks, a lady with the imposing name W. S. S. Van Benthem Jutting studied Irian’s non-marine mollusks in the early 1960s, before the province’s intergration into Indonesia. Her work was published as a series of four monographs in that font of wisdom, Nova Guinea. Her work is summarized (by R. H. Cowie, in Beehler 1993) giving a total of 481 species for these gastropods or land snails. This is probably similar to the number which could be found if a similar survey were to be conducted PNG, although the total ‘not inreasonable’ number, according to Cowie, is probably closer to 1000. (Cowie mentions another list, with 198 ‘Papua’ species, but it is unclear as to just what area this covers.) Aside from the non-marine species, our intrepid lady gives us 165 fresh and brackish water gastropods and bivalves. But so little work has been conducted on this ecosystem that Cowie concludes that ‘It is not possible to estimate the total number of species in the fauna’.
V. Shrimp, crayfish and crabs: the crustaceans
Freshwater crustaceans only occur south of New Guinea’s central mountain range. All forms are derived from Australian parent stock as north Australia and south New Guinea were part of the same river drainage area. Now New Guinea has two endemic genera and two still in common with Australia. That there are no Asian fresh water species proves the existence of permanent barriers between the Sunda and Sahul shelves.
Decapod (ten-legged) crustacean species fall into three categories, with a total of six families:
1. Atyidae and Palaemonidae for shrimp
2. Parasticidae for crayfish
3. Hymenosomatidae, Grapsidae, and Sundathelphusidae for crabs.
Of these six families, only the last two are exclusively fresh water dwellers. The others families all have members which spend part of their time in salt water. There are many families of marine crustaceans in New Guinean waters, in common with areas east, west, north and south. The decapod crustaceans are represented in New Guinea by at least 87 species which include 31 or more endemics.
Of the families with representatives in the island’s fresh waters, the most interesting are the Parasticidae, a spectacular feature of the island’s endemic biota. The family is restricted to the southern hemisphere, with disjointed distribution. The Australian area boasts of many genera, including Cherax, the genus for all the New Guinea’s 13 species of crayfish. From this total, eight are from the central cordillera, from the Paniai Lakes area, at elevations from 1650 to 1750 meters. And these are well-behaved species, never wandering to places unexplained by geological history or geographic barriers: no headaches to zoogeographers. Aside from the species at the Paniai Lakes, we find the Cherax monticola as a nutritious source of protein in the upper Baliem Valley, sampled by many a delighted tourist in Wamena. To the west, Cherax lorenzi spreads from the eponymous Lorentz River all the way to the Bird’s Head peninsula.
The Palaemonidae, are represented by only two genera: Macrobranchium and Palaemon. While the first of the genera is considered a fresh water inhabitant, a few species prefer brackish water or even a marine milieu. These usually have to spend a part of their youthful development in highly saline waters. The genus Palaemon is widely distributed, from the Red Sea to Polynesia. There are at least 18 species of Macrobranchium in New Guinea. Three of these are endemic: M. lorentzi, M. minutum and a yet-unnamed species from near the Paniai Lakes. The two most sought-after species, due to their size, are the M. rosenbergii whose range extends from India to Australia and the M. mammilodactylus a Malaysian species. This second species, like several others, reaches the eastern limit of their range in New Guinea.
Of the many crabs found on the island, only the family Sundathelphusidae has truly fresh water species. Some of these are puzzling to zoogeographers as there are various species both to the south as well as to the north of the central mountains. These do not block the path of the fresh water crabs as they do for the crayfish. The Hymanosomatidae family boasts of many genera and species, but most of these are marine. The family Grapsidae, also mostly marine crabs, shows two main divisions: the subfamily Varuninae, and the subfamily Sesarminae. The varunins, with four species, are found in fresh water but in brackish and marine waters as well, so no exclusive fresh water status for them. The crabs of the genus Sesarma live on mud flats and mangrove areas, usually near river estuaries. Thus they can not reach exclusive fresh water status either. There are plenty of species in the Ocypodidae family (genera Ocypode and Uca) living in both fresh and brackish waters. Several species of hermit crabs (Coenobita spp.) and coconut crabs are found in many areas of New Guinea, with the exception of the genus Birgus (the common coconut crab) absent from the south coast.
Except for the Timika area (see below, Section Two), research and surveys of marine and estuarine mollusks are almost totally lacking for New Guinea (execept for Van Benthem Jutting). In the category of non-marine mollusks, we have over 1000 species, of which the best known are the stunning land snails belonging to the Camaenidae family (with the genera Papuina, Chloritis and Theristes) and a few other operculate land snail families as well. The beauty prize here goes to the Papustyla pulcherrima, an aptly named tree snail (pulcherrima means most beautiful in Latin), with a bright green shell so sought by collectors that a newsletter is devoted to this gastropod. The prosaic common name of the animal, the Manus Tree Snail, reflects is endemic status, confined to Manus Island. For aficianados, there is even a newletter called The Papustyla, so prized is it by shell collectors (Beehler, 1993)
VI. Beetles and butterflies: the insects
According to the scientists working on the various groups of insects, there is no doubt that New Guinea ranks near the top for the total number of species and the total number of endemics for any area of comparable size. Estimates range to as high as 300,000 different species. While various insects groups have received some attention, only beetles and butterflies are relatively well known. For beetles and several other insect groups, much of the current level of knowledge is due to J. L. Gressitt, an entomologist from the Bishop Museum in Hawaii who established a field station at Wau in PNG in the early 1960s. He encouraged other scientists to study the area’s rich insect fauna as well as other animal groups. (The herpetologist Allen Allison joined the staff in 1973.) The results of two decades of insect work at Wau was synthesized in a book he edited in 1982: Biogeography and Ecology of New Guinea. A partial list of new species found include 40 cicadas, 134 ground beetles, 69 tiger beetles, 32 butterflies (species and sub-species).
On the Iran side of the border, insects have not had the privileged of any sort of sustained attention. A recent estimate from the WWF gives the total number of insects for Irian as 200,000 with 2400 to 3000 Lepidoptera. (Barrano, 2002). Freeport has conducted some surveys (see below) and Conservation International has also carried out some field research through several rapid ecological assessment programs. In the first one of the series was at Wapoga, an unexplored area covering the highland-to-lowland transition zone to the north-east of Nabire where Freeport provided camp facilities to the scientists. Here the survey found 36 new species of Heteroptera (true bugs), two new Zygopetera (dragonflies and damselflies), ......????.... new Gyrinidae (whirlygig beetles) and 17 new types of ants. (CI for data from other RAPs)
While we know of only one insect farm in Irian, at Manokwari, there were some 800 at one time in PNG. This ideal local grassroots conservation industry requires very little capital investment. The most valuable insects raised are the birdwing butterflies, including the species Troides goliath (world’s second largest), T. paradisea, T. primus, T. oblongomaculatus; the Ulysses Swallowtail, Papilio ulysses and other swallowtails Graphium, Papilio, and Taenaris spp. For beetles, the best sales come from the Longhorns, Ceramgydidae, spp. and the Rosenbergia species, along with the scarabs, Scrabaeidae, the metal woodboring beetles, Buprestidae and the stag beetles, Lucanidae. A few insect lovers will also pay for the commercially valuable bird-eating spiders and giant millipedes. For the insect farms to grow, more capital is needed and for the sake of conservation, scientists recommend not to concentrate exclusively on dead specimen but to furnish live pupae for insectariums in museums and universities.
New Guinea holds an almost incredible variety of insects, despite its geological youth. This diversity is equivalent to the older tropical lands of south-east Asia, a much larger geographical area, from where most of the parent stocks came to the island. There may be fewer genera than in Asia but the species richness is unparalleled. It has been scientifically guessed that in Irian Jaya alone there are some 150,000 to 300,000 species of insects. But it is going to take a long time to find and catalogue them all. The basic reason for the high number comes from the fact that when insect species invaded a young New Guinea, recently raised from the seas, there were many new, unoccupied habitats, especially in the mountains, which led to rapid speciation.
Add to this the typical plant diversity found in the tropics and the result is lots of insects. This plethora is also due to the fact that in the tropics the reproductive cycle does not need to take time out for the cold to pass, thus there are more generations each year. More generations mean more possibilities for speciation. In the tropics, we also have more ecological niches due to more types of vegetation. This also leads to insects adaptation, thus speciation.
It has been estimated that when we include all the flora and fauna of New Guinea, only 10 per cent is of Australian origins, with 30 per cent coming from Asia and the remaining 60 per cent being endemic. We have already seen that the main reason for the low input from Australia comes from the fact that the transition zone to New Guinea was hostile to tropics-adapted life found in most of southern New Guinea. Thus much of the Australian-origin fauna is restricted to the relatively dry savannah areas in the south-east, around Port Moresby and in the south-center of the island, to the east of Merauke. For example, butterflies are generally poor travelers, with desiccation the greatest danger they face. They have serious problems moving across ecological barriers different from their home grounds. Some groups, even if strong fliers like the Ornithoptera, are restricted by differences in the ecology of the transition zones. There are some butterfly species which do move across these barriers, but only passively, by strong winds generated during long storms. Other species, even some of the smaller ones, cover great distances in flight and find new homes thanks to their adaptability to different larval and food plants.
Aside from the tropics-induced creation of new species in the lowlands, conditions in the mountains also led to considerable speciation. As the mountains rose in the center of New Guinea, trees adapted to this new cooler, moist-temperate climate, producing new species: most of the highland angiosperms are endemic. As the trees evolved, so did the insects living and feeding on these trees. Thus the lowland, tropical archipelago of the Tertiary Period, which eventually coalesced to form New Guinea, started the process of high numbers of local endemics, with this speciation given a strong boost by the ecology of the rising mountain ranges. In spite of its geologically recent formation, it seems that the island’s insect diversity equals the much older (thus more time to evolve) tropical Southeast Asia (Gressit 1982). As with other life forms, this applies to species diversity, but not to higher taxonomic orders such as genera and family. New genera take much longer to evolve.
While there is some general knowledge about insects, much of it is assumed. Most groups have not been blessed with sustained studies. Except for butterflies, and to a lesser extent beetles, most insect studies are not very sexy: no Nobel prizes, no public acclaim, no groupies for discovering and naming anonther damn flea. It just happens that fleas are one of the better known groups in New Guinea: pure decication and no limelight. Of the 31 orders that divide the insects, only three are unknown in the island: Megaloptera (alderflies, dobsonflies), Raphidioptera (snake-flies) and Mecoptera (scorpion-flies). Many are but poorly known or have but scattered references in the literature. Some of these orders do not even have a common name, and if they do, it’s unfamiliar to the non-specialist public. In the poorly or very poorly known categories we have the orders Collembola (springtails), Ptotura, Diplura, Archaeognatha (bristletails), Thysanura (silverfish), Ephemeroptera (mayflies), Plecoptera (stoneflies), Psocoptera (booklice), Phthiraptera (lice), Thysanoptera (thrips), and, within the beetle group, the poorly know include the Scarabaeidae (scarabs) and the Curculionidae (weevils). On the next level, we have the orders which have received ‘scattered literature’: Blattoidea (cockroaches), Isoptera (termites), Dermaptera (earwigs), Orthoptera (grasshoppers, locusts, katydids, crickets), and Phasmatodea (stick-insects). In the relatively well known group, we have the Odonata (dragonflies and damselflies) thanks to a chap named Lieftinck; Embioptera (web spinners) with thanks to Ross; Hemiptera (including Heteroptera and Hompotera: bugs, leafhoppers, cicadas, aphids, scale insects and more); Neuroptera (lacewings and others) with thanks to a bloke named T. R. New, Siphonaptera (fleas) due to a monograph by Holland, may he bask in his 15 minutes of fame, but no kiss from Madonna; Diptera (flies) with some subgroups well known, such as the Culicidae (mosquites) to very poorly known: it’s obvious that there there are many more flies than the common, bothersome, houseflies, irksome and disease-spreading buggers; Trichoptera (caddis-flies) faint praise for Neboiss, as he left out many taxa; Hymnoptera (wasps, bees, ants and sawflies), a most diverse group with from the relatively well known ants to the many and very poorly known but crucial parastic wasps which contol a host of insect pests by killing them and laying their eggs on the decomposing bodies so the little ones can eat their fill. This leaves us with the two best known orders, the Coleoptera (beetles: remember the bit about God being so fond of them that He made lots and lots and lots more of them) with some families well known, others much less so. And the Lepidoptera, the butterflies and moths. The butterflies of PNG now have been blessed with a huge and excellent (but very, very expensive) tome (Parsons, 1999) out of print two years after publication, which shows that butterfly fanatics are rich. However, moths are neglected, and even the larger ones, some of which can comptete with most butterflies for beauty, have no monograph. A damn shame, as one sees lots of these but tying to identify them is almost impossible. (adapted from Beehler, 1993, with irreverent comments by the semi-inebritated author)
For many years, the team of Dan A. Polhemus and J. T. Polhemus have studies three groups of aquatic insects as indicators of biodiversity and biogeographic regions, in both halves of New Guinea. The three goups are Odonata (dragonflies and damselflies), Coleoptera of the Gyrinidae family (whirligig beetles) and Hemiptera (aquatic bugs).
The world count for butterflies comes close to 20,000 species, and if we add moths, it’s a quarter of a million. For its size, New Guinea can boast of the most diverse butterfly fauna in the world: 820 species in PNG and 960 with Irian included. It is likely that further field work will push this total to over 1000. Some 55 per cent of the species are endemic. In comparison, Europe (six times New Guinea’s land area) has only 380 butterfly species and Australia (nine times larger) holds 383 species, with an endemicity of 46 per cent. In Australia, the endemics are almost exclusively found in the temperate lowlands, in the open grasslands while New Guinea’s endemics are tropical, found in the montane areas of moist forests. As far as absolute numbers (not endemics) of butterflies, only the Malaysian Peninsula, with 1,031 species can compare with New Guinea. There the ecosystems of the Asian mainland and the south-east island meet. And thanks to British collecting mania, amateur and professional butterfly seekers have been active for well over two centuries in Malaysia due to ease of access.
We have seen how the geological and climatological history of New Guinea affected its high endemicity for both plants and animals. In the case of butterflies, one area will help to illustrate this. The Arfak mountains in the Bird’s Head were first formed as an island. When incorporated into the leading edge of the Australian plate in the Late Oligocene, it was the first area to be colonized by biota from the rich tropical Malaysian and archipelagic area. But as the mountains rose, the higher elevations became isolated again, while giving the necessary habitat for speciation: today, there are 23 endemic species of butterflies there.
The 440 endemic species found on the island of New Guinea account for almost half of the total number of butterflies. As with other animal groups, the total number of endemic genera is low but the species numbers are high. Of the 169 genera found on the island, only some 20 per cent are endemic while for species it’s well over half. Except for the lowland genera Perpheres and Hyantis, most of the endemic genera are found in the mountains. Of the montane endemic genera, we have sartyrines of the genus Neonypha, with gray or brown wings and eyespots on their wings. The highest diversification on the island is by the pierid butterflies, family Pieridae, which are small or medium sized white or yellow in color with dark markings. A genus of this family, Delias, very popular with collectors, holds 165 species (so far), of which some two thirds are endemic. Most live in restricted ranges above 1000 meters. Many have their habitat above 2400 meters, with a few up to 3600 meters. (Parsons 1999). There is a very good reason for this. The species depends on mistletoes as their food plants. As the mountains rose, the speciation of mistletoes encouraged the parallel speciation of the Delias, a process still on-going. In contrast, the genus Ornithoptera, with only ten species in New Guinea, is restricted to the lowlands where they depend on a few species of Parasistolochia as their foodplants. These plants have not evolved into nearly as many species as have the mistletoes. In a different evolutionary strategy, the genus Philiris has become a generalist in its food-plant choice. Given the possibility of feeding on a wide range of plants, the genus has been undergone considerable speciation in New Guinea.
There are five butterfly families in New Guinea, with greatly varying numbers of species in each one.
The Family Hesperiidae has 18 per cent of New Guinea’s butterflies. These are commonly called skippers, due to their rapid and darting flight. The size varies from small to medium, with a usual brown base color but some species have bright colors, especially orange. There are no visible differences between the sexes. With a head as broad as the thorax, some species appear like moths although no single factor can distinguish between these insects.
Family Papilionidae. Only four per cent of the butterfly fauna on the island fits into this family, but these are the biggest and most spectacular ones around. They are the most prized by collectors due to their size, beauty, colors and extreme differences between sexes of the same species. They are commonly called swallowtails due to a hindwing extension which can be either pointed or like a spatula. But several species lack tails and do not have this extension or only featured by the males. The family is represented in New Guinea by four genera, including the well known Ornithoptera, the huge birdwings, much sought for sale. They are now illegal to export, unless raised on a butterfly farm. One of the subfamilies, Troidini, and especially the genus Troides, feeds on a diversity of vines of the genus Aristolochia (total of some 500 species world-wide, a part of the birthwort family) during the larval stage. The plant and the butterfly genera are of great antiquity and evolved together. The vine is known for its many toxic substances which are absorbed and stored by the larva for protection. The larvae are aposematically colored, meaning in a way to warn predators: bright red, orange, yellow and white patches highlighted on a dark background. You can’t miss them, but you better not eat them.
The Family Pieridae’s butterflies, evolved from the same line as Papilionidae, make up 15 per cent of the New Guinea butterfly fauna. They are usually white, yellow or butter colored, this latter coloration leading to the common name for this portion of the Order Lepidoptera (the other insects of this order are the moths). The family includes the genus Delias, with 165 species world-wide of which 116 species are from New Guinea (63 in PNG plus 53 from Irian). The genus is either centered on New Guinea, with most species above 1000 meters and to 3600 meters. They are rare and very localized with restricted ranges, but common in these small areas. The flights of many of the pierids are stimulated by sunlight and Delias settles as soon as clouds darken the sky. They often fly above the trees of very specific ridges and summits.
Family Lyaenidae makes up 40 per cent of the butterflies in New Guinea. They are usually called blues, with the names coppers (for those of metallic-orange coloration) and hairstreaks also used along with many other common names. The species are quite diverse morphologically, with many tailed and non-tailed ones. The family often shows upperside wings of delicate purple and blue, with black tips and margins. The body size is often small, but with bright colors and much variety. Two genera, Philiris and Hypochrysops have greatly speciated in New Guinea.
An intimate association with ants is an unusual and fascinating characteristic of this family. The larvae often stay in ant nests, occasionally eating their hosts’ larvae and pupae (sometimes as their principal or only food), along with aphids, scale insects and leaf hoppers. Perhaps the carnivorous habit resulted from the larvae’s close association with ants. Some species of the butterflies’ larvae spend their days inside the protection of ant nests, coming out only to feed at night, sometimes accompanied by ants who guard them. In a few cases the ants actually to feed larvae in their nests. A pretty amazing feat for a parasite. The lycaenid larvae have evolved a shape which is compact and protective, with retracted head and legs and a very tough skin. In addition, the larvae produce three types of secretions. These are used to pacify or bribe the ants, nectar-like fluids which the ants drink. The larvae can also produce an alarm secretion which can alert the ants to gather and scare away an animal trying to make a prey out of the butterfly larvae. This very unusual form of protection, plus the ability to eat a bewildering range of plants have allowed the great speciation of this family of butterflies.
The Family Nyphalidae takes its name from a poetically inspired Linnaeus as it means ‘adorned nymphs’. It makes of 23 per cent of the New Guinea butterfly species. Some of the common names are demains, browns and nymphs. This is the most diverse family, with close to the same number of species as the Lyaenidae. They are extremely varied in color and wing pattern, some species showing seasonal variations not only in color but also in wing shape, more than enough to frustrate any weekend collectors trying to identify his catch. And as an added complication, the hindwing tails can be absent, or if present, vary greatly in number and length. Some species blend in with the bark or foliage where they live, while others are aposematic, meaning brightly colored, to warn potential attackers of their poisonous bodies. The subfamilies of the Morphinae and the numerous Satyrinae are especially distinctive due to their large number and variety of eye spots on the wings. This is especially true for the genera Parantica, Euploea, Morphosis, Taenaris and the Hypocysta. The satyrine butterflies, especially on the endemic genera Altiapa and Platypthima, both often found in the mountains, probably have many species waiting to be discovered.
A recent breakdown of some butterfly groups in Irian (Van Mastricht in Barrano, 2000) lists the following:
Papilionidae: 27 species, 5 genera; 23 species in the lowlands, 6 in the montane area and four in the highlands. There is a high degree of endemism in this family. The members in the Ornithopera genus are as follows: Ornithoptera priamus, O. goliath, O. rothchildii, O. meridionalis, O. paradisea, O. chimera and O. tithonus. In the genus Papilio we have Papilio ulysses, P. demoleus, P. euchenor, P. ambrax, P. fuscus, P. albinius, P. aegeus and P. laglaizie. For the genus Graphium, the list covers Graphium codrus, G. agamemnon, G. aristeus, G. eurypyhis, G. macfarlenei, G. sarepedon, G. thule, G. weiskei and G. wallacei. Add to this Troides oblongimaculatus and Pachliopta polydorus.
Other families, numbers and distribution are given as follows:
Pieridae, over 110 species in less than 10 genera; lowlands, 10 species, midmontane, 20 species, highlands, 80 species.
Danaidae, 40 species in 6 genera; lowlands, 35 species, none midmontane, and five in the highlands.
Nymphalidae, 80 species in less than 40 genera; lowlands 50 species, midmontane, 10 species and highlands, 20 species.
Satyridae, with 50 species in 7 (or more?) genera; lowlands, 35 species, midmontane 10 species, highlands, 5 species.
Amathusiidae, with 30 species in 5 genera; lowlands, 25 species, midmontane, none, highlands 5 species.
Lyberthidae, 10 species in 2 to 3 genera; all ten species in the lowlands.
Lycaenidae with 250 species in over 100 genera; over 50 species in the lowlands, over 50 species in the midmontane area and over 150 species in the highlands, with a high degree of endemism.
Rhodinidae with 20 species in 3 to 5 genera; 5 species in the lowlands, none in the midmontane area and 15 species in the highlands.
Butterfly or moth?
Both butterflies and moths own a proboscis (an elephant has one too), usually in the form of a coiled tube. So how can they be differentiated?
The butterflies’ antennae are long, slender and always knobbed at the end. (No such luck for moths: plain antennae are their sad fate.) The way to really tell the members of the butterfly/moth family apart is essentially by wing venation. But forget it: most venation is obscured by scales, requiring bleaching to see properly. Stick to the wing patterns and colors. It may not be as accurate but it’s a hell of a lot more fun. My own take on all this is that butterflies are pretty, both at rest and when flying. Moths tend to be hairy, fly erratically and sometimes into you. But sometimes they display pretty and intricate wing patterns. The larvae of both are called caterpillars and have salivary glands modified into silk glands, but the butterfly pupae have the pretty name of chrysalids (one: chrysalis; plural: chrysalids) and no such luck for the moths; this is perhaps because moth pupae seem sculptured and sometimes sport bright colors while the moths’ offspring start as brownish and smooth. By the way, metamorphosis goes: egg > larva > pupa > adult. Don’t ask why: it’s too complicated.
Pretty or not, the larva of many butterflies and moths alike are awful pests of both cultivated plants as well as grain and flour.
Unfortunately, life is not so simple. The more scientists find out about these two groups of insects, the harder it becomes to tell them apart. The old accepted wisdom had moths flying at night, their antennae without clubs at the tips and with stout, hairy bodies. Butterflies were said to fly during the day, had club-tipped antennae and fairly slim bodies in comparison to wing-spread. Not so easy, although the general rules above still apply, but only to a degree. Many moths in New Guinea have become day-fliers, are decorated with bright colors and with behavior resembling butterflies. On the other hand, some of the butterflies, especially the hesperiids, closely resemble moths as they have stout bodies, with short legs and pointed, not clubbed, antennae. All other butterflies however do have antennae, thickened into clubs, at the end of smooth, filiform, usually erect stalks. Moth antennae are difficult to characterize as they are very diverse in shape and structure, but speaking very generally, they are tapered towards the ends, with a series of hair-like setae, making them look feathery. While resting, moths usually fold their antennae under the wings. The wings are in turn folded alongside the body, exposing the forewings. Most (but not all) butterflies fold their wings vertically over their backs to expose the underside of the hindwings. Summing it all up, there is no single factor to distinguish between them.
Aside from butterflies, beetles (and malarial mosquitoes) are the only group of insects to have received much attention from scientists. ‘God must have had an inordinate fondness for beetles because He made so many of them’. This famous phrase, usually attributed to the 19th century naturalist Thomas Huxley, certainly applies to New Guinea. The island hosts about one tenth of the world’s total of 250,000 species, close to one third of all insects on our planet. Beetles are divided into 100-odd families. Most of these families have representatives on our island. While superficially resembling the much more primitive cockroaches, beetles differ in their metamorphosis. Cockroaches undergo three stages, egg, nymph and larvae before becoming bothersome adults while beetles pass through a ‘complete’ set of changes from egg to larva to pupa to adult.
Beetles were one of the earliest groups of insects to evolve and those species which were found to be involved with palms are often members of primitive beetle families, in particular Curculionidae (weevils) and Nitidulidae (nitidulid beetles). The commonly eaten sago grub is known as a weevil, a term which applies to all the members of the Rhynchophora/Curculionidae group. Weevils are distinguished from all other beetles (whence the different name) by the head prolonged into a distinct snout or beak which is curved downwards with the jaws at the tip. The antennae are clubbed and elbowed. Most of the weevils (rhymes with evils) are awful pests, especially in the larval stage, to nuts, fruits and grain of living plants.
Beetles are similar to many other insects in have three pairs of legs and a pair of antennae. But they are different in the protection offered by a pair of fore-wings called elytra. This appendage is hardened to form a rigid armor which covers the membraneous hind-wings used for flying as well as the lower part of the thorax and the abdomen. Thus beetles have a harder exoskeleton than most insects. The eggs may be either naked or enclosed in a sheath which can be glue-like, waxy or papery. The larvae usually develop in a protected environment, such as under bark or inside a tree, so in comparison with other insects, they do not proportionally form as an important food component for birds and other predators.
Predators on adult beetles include mammals, lizards (especially skinks), frogs and toads as well as birds and sometimes even humans. Other bothersome creatures to beetles include parasitic wasp or fly larvae, along with lower animals such as some protozoans and nematode worms. Some beetles are predators themselves. This is especially true of a group called the carabids, including tiger beetles, most water beetles, most staphylinids. They keep down the numbers of insects and some vertebrates such as land snails. The lady-bird beetles very effective in controlling crop pests among aphids, white-flies and scale insects. Plants are the main food source for other beetles, especially the chrysomelid, weevil and scarabaeid groups. These may consume leaves, bark, heartwood, seeds or roots. The alimentary canal is quite short in the predatory beetles and longer in the plant-eaters.
Another group, the scavenger beetles, are useful in breaking down dead plant material, thus forming humus and soil. Boring beetles (cerambycids, weevils, bark beetles) feed off decaying wood. There are also dung feeders and carrion feeders. Several species live in termite nests or ants’ nests. They produce food for their hosts from specialized glands.
Some ground beetles can emit a fluid which produces a small explosion with brief but intense local heat which can burn and stain human skin. Aside from these, there are beetles producing excretions resulting in blisters on humans. Some beetles produce stridulation, a special sound to frighten enemies by rubbing two of their body structures together. Other special adaptations include nurturing new plant growth on their backs for camouflage. Some feign death, folding their appendages so as to resemble seeds or pebbles.
While many of the more conspicuous elements of New Guinea biota, mammals and birds, arrived from Australia, the majority of plants and insects, adept at crossing relatively narrow sea passages, arrived from the west. They found the climate to their liking while the Australian plant and insect species are mostly limited to the environment similar to their place of origin: the open savannah which in New Guinea is restricted to some sections of the southern portion of the island. The New Guinea plants and insects which spread to Australia also sought a similar environment to their origins and found this only in the north Queensland rain forest.
Beetles are found from the tidal zones next to the seas to some of the highest elevations, as the top of Mt. Wilhelm. As with plants, beetles thrive in the lowlands with many different species but fewer individuals hanging out together while at high elevations there are fewer species but individuals of one particular species are more abundant. The lowland species are widely distributed while at altitude their range is more limited and there are more endemics: one particular species may well be restricted to a single mountain area or highland valley, within a fairly narrow altitude range.
The plethora of beetles in New Guinea makes identifications difficult to say the least. Non-entomologists can only consider the combination of body proportions, size, shape, contours, types of antennae and tarsi (small segments which articulate with the tibia, the major leg segment). Our beetles vary in size from tiny to 125 mm. (world-wide, their size range extends from a few millimeters to 200 mm.) Some of the most conspicuous external physical features include the horns of the rhinoceros beetles, the very long jaws of the male stag beetles and the long jaw-equipped snout of the weevils. At night, the fireflies (a misnomer, as these are beetles) can put on spectacular displays of light, twinkling either in unison or each to his own beat.
The beetle families
While just about 100 beetle families live and love in New Guinea, we will look at only the most conspicuous and better known ones. While the list of beetles on the island is already an impressive one, many more species awaiting discovery.
The beetles are divided into two suborders, the adephaga and the polyphaga. In the first one, we have four well-known families. The Carabidae family, are commonly called ground beetles, but not all conform to type in New Guinea: one third of the species live in the foliage, on tree trunks, among the mosses and epiphytes, or under bark. Their legs are long, thus these beetles are fast moving. They are predaceous, hunting and feeding on other insects, worms and larvae, thus presumably control other insect populations. Most are dull or shiny black, others, especially those living in trees, are of shining green, bronze and coppery colors. The Cicindelinae family are the tiger beetles, so called because a pair of fearsome downward directed mandibles can deliver a painful nip to any human with a careless handling technique. These beetles carry a dull black background but adorned with intricate designs of white and yellow as lines or spots.
The Dyriscidae are diving, carnivorous water beetles. They feed on almost anything small enough, dead or alive. Their prey includes even fish! The larvae (called water tigers) have large sickle-like jaws and suck the body contents of the prey through channels in the jaws. Adults are oval or boat-shaped, they are usually black, often smooth and convex and streamlined. Their size ranges from a few millimeters to over 30 millimeters. In the Sepik River area, they are caught with small nets and valued as food. These beetles are rapid swimmers with specialized paddle-like hind legs, surfacing for air but able to stay long periods underwater thanks to a bubble stored between elytra and abdomen.
The Gyrinidae are the whirligig beetles, taking their common name from the family’s typical gyrations in groups on water. Their fore-legs are particularly long and extend in front of body. They differs from nearly all other beetles by having two pairs of eyes: one set for looking out for enemy and prey above the water and the other pair for below the water surface. They are predaceous. Some adults, when handled and stressed, give off a smell like pineapples.
The other beetles in New Guinea belong to polyphaga (eclectic feeders: eat anything) suborder. The Lucanidae family groups the stag-horned beetles, with some very large and handsome males with their impressive mandibles. The females are much smaller and their mandibles are nothing to brag about. In the impressive-beetles category, we also have the longicorns of the Cerambycidae family. This group includes some of the largest and most striking beetles found anywhere, with sizes ranging from three to over 100 millimeters. These long-horned insects are generally elongated and slender, with the males’ characteristic antennae two to three times as long as the body. Just as spectacular as the two previous families, we have the rhinoceros beetles of the Dynasinae family. The horn vary a great deal between species and even individuals of the same species. But unusual and eye-catching as their single ‘horn’ might be, many are agricultural pests. Other unwanted beetles include a species called Cylas formicarius, of the Apionidae family. These are specially deleterious in New Guinea as they feed on the sweet potato, the Papuan highlanders’ staple. While many beetles are anathema to human agriculturists, one family is highly appreciated by farmers. These are the ladybird beetles of the Coccinellidae family. Many species live in New Guinea, with the majority uniformly colored dark brown or back. Some have conspicuous yellow and black or red and black patterns, much like the ladybirds in temperate climes. Both larvae and adults play a role in controlling aphids and scale insects pests, which they consume large numbers.
The scarab beetles, family Scarabaeidae, are generally stout bodied and among the largest insects in the order in world. The terminal segments of antennae are specialized to form a club of three to seven moveable plates or lamellae. The legs often specialized for digging, with widening of some segments, and extension of the claws which may carry an elaborate group of bristles and hairs. No insect can compete in any beauty contest with the Bupresidae family, the aptly-named jewel beetles. These wood-borers can justly boast of beautiful markings of metallic blue, green, gold or copper colors, with sometimes the entire body thus clad.
Two other families are most unusual, one for its sound, the other for its lights. The click or snap beetles of the Elateridae family produce their typical sound through the muscular articulation between the prothorax and the mesothorax. The sound is made both to escape as well as to upright themselves when helpless on their backs. The mis-named fireflies, the beetles of the Lamprydae family, produce a sex-attracting light thanks to low-temperature oxidation triggered by special enzymes. They have the unique ability to flash their lights on and off: other luminescent insects glow continuously. For the technically minded, the light in these beetles is produced by low temperature oxidation brought on by special enzymes. Some of their night-time displays create a magic fairyland as trees are set alight with hundreds of twinkling or synchronous tiny points of light. Near the south coast, these beetles often do their number on the trees Avicennia officinalis and Hibiscus tiliaceous, with no season for the performances.
The beetles of the Chrysomelidae family belong to one of the largest families in the world, ranked number two or three in species numbers. In New Guinea some 5000 have been identified so far, but only around 1000 have been named. They are leaf-eaters, at least when reaching the adult stage. But if there are lots of chrysomelids, there are even more members of the Curculionidae family. This is the largest family of animals in the world, the infamous weevils. But some are also considered absolute beauties, especially those belonging to the genus Eupholus, sporting brilliant metallic scales. All are restricted to at least 900 meters’ elevation.
Weevils are always associated with plants, mostly woody ones. They feed on nearly any and all parts of the plants, some wood-borers, some root-feeders, especially in the larval stage. Larvae are usually white or pale creamy, with a brown head and usually lacking legs; they are a major agricultural pests in New Guinea. The worse from a human point of view are the Rhychophorus and related genera. They attack cacao, peanuts, vegetables, palms, coffee plants, bamboos, grasses, and in particular monocots such as bananas. Not only that: they can seriously damage stored crops, especially grains, timber (including Araucaria) and other plant products. As to be expected, these are the hardiest of insects, tough to kill thanks to their compact, heavily protected bodies (sclerotized). The adult body forms vary greatly, some being long and slender, others almost spherical. The family is characterized by a long snout (rostrum) or elongated front portion of the head, tipped with the mandibles. But, just to keep a perspective again too broad generalizations, others, called short-nosed weevils, sport a snout as long as broad. Papuans in many areas of coastal New Guinea purposely cut down the sago palm tree, which provides their staple food, to make a convenient home for sago grubs. These are a much appreciate source of protein, consumed alive or roasted, as a gastronomic delicacy.
VII. Fresh water fishes
There are 445 families of fishes in the world, of which 55 are found in New Guinea fresh waters. All of them are bony fishes (except for a part-time shark) called Osteichthyes and belong to an order called Perciform which embraces most marine reef fishes as well as many of the freshwater forms. The total fish count for New Guinea waters runs to around 2500 but most of these are marine. If a generous definition is given for freshwater, we can count 375 species. About one third of this total have a marine larval stage, thus making them wide-spread. The ‘true’ freshwater ones, with no marine involvement, only number some 200. A recent WWF publication pegs Irian’s freshwater population at 227 genera grouped into 44 families. The richest zone is the Southern New Guinea lowland rainforest, with 22 families. (Barrano, 2002).
As with other animals groups, the number of fish species found in New Guinea increased each time a qualified researcher enters a new area - in this case, Dr. Jerry Allen, the freshwater expert for the whole island has added an almost incredible number of 75 new fish species to the scientific literature. The breakdown is as follows: 35 species of rainbowfishes (including one new genus), 9 species of blue-eyes, 14 species of gudgeons, 9 species of gobies, plus 8 species in various other families.
Of the 329 species listed by Dr. Allen, he considers 15 to be non-indigenous, or introduced. A fair number of fishes, 102 to be precise, are estuarine, able to live in waters of relatively high salinity. Of the 217 strictly fresh water species, 149 or 70 per cent are endemic. Dr. Allen estimates that the final tally for the island will be around 400 species, twice what has been found in Australia. But this still leaves New Guinea well behind the numbers game. The fish species in Kalimantan’s Kapuas River number some 300 while about 2000 species live in the Amazon Basin.
While there are only 33 species shared with northern Australia, the two most interesting families, the Melanotaenidae (Rainbowfishes) and the closely related Pseudomugilidae (Blue-eyes) are unique to Australia and New Guinea. Between the two families, there are 83 species, including 56 on the island.
There are some 40 fish families in New Guinea, or, 56 if we include introduced and occasional freshwater ones. The numbers are dominated by eight families accounting for two thirds of the species. The family groups called the arherinoids (rainbowfishes, blue-eyes and hardyheads), plotosids (eel-tailed catfishes), ariids (fork-tailed catfishes), teraponids (grunters) and goboids (gobies and gudgeons). All of these families are derived from marine ancestors and they make up about two thirds of the island’s fresh water fish species. The recent nature of the fresh fish fauna in New Guinea is underlined by the fact that all naturally occurring fish species are either diadromous (migrating between fresh and salt water) or direct descendants of marine families. The only exception, according to Dr. Allen, is ‘the Bony Tongue, Sclerophages, which belongs to an ancient group at apparently evolved in the fresh waters of Gondwanaland.’ (personal communication) Not enough time has passed for the evolution of many new fresh water species in New Guinea. Nearly all are descendants from marine ancestors in recent geological times.
Up to some 6000 to 8000 years ago, the river systems of southern New Guinea and northern Australia were joined into the low-lying area which is now the bottom of the Arafura Sea. Whereas in Africa of S. America, fresh water species evolved entirely in fresh water, in New Guinea we have mainly ‘secondary’ fresh water form. Many of these are relatively tolerant of saline waters, compared to the primary ones which have lost this tolerance and normally can’t even cross narrow marine barriers. Only two purely freshwater species, a rainbowfish and a gudgeon have managed to ‘cross’ the central mountains as they are found both on the northern as well as the southern drainages. Thus the island presents two different but closely fish faunas.
No native fishes are found above 1800 meters in New Guinea. This is mostly due to the area’s violent geological past with simultaneous volcanism and glaciation, not very propitious for fish evolution. The current altitude record of 1750 meters is held by a fellow named Oxyeleotris wisselensis. Two trout species have been introduced to higher areas, the Rainbow trout, Oncorhynchus mykiss, and Brown trout, Salmo trutta. In the lowlands, the most common of the non-indigenous species, the tilapia Oreochromis massambicus, had become a plague in some areas as it is voracious and out-competes local species, possibly to extinction. In the Sepik-Ramu basin of PNG, this species already accounts for over half of the catches by the Papuans.
Dr. Allen divides New Guinea into several major ecosystems to better delineate the freshwater species in each. Blackwater streams (so called because of their coloration due to the tannins leached from decomposing vegetation) commonly hold ariid catfishes, rainbowfishes, garfishes, gudgeons and gobies. These rivers are generally richer in fish fauna than the large, muddy rivers, so one often sees fishing villages next to them. In the lowland rivers, with turbid waters and silty or muddy bottoms, the aquatic vegetation is poor, thus less fish life. Here we can find ariid catfishes, which are common, along with marine visitors such as croakers, silver biddies, ponyfishes and juvenile trevally.
The floodplain lakes, swamps and backwaters cover huge areas with good quality water rich in aquatic plants providing ample hiding places for juveniles. Common here are rainbow fishes, gobies, gudgeons and the ubiquitous ariid catfishes. In the upland tributaries, with very clear water rapidly changing level and a general lack of aquatic plants, Dr. Allen points out eel-tailed catfishes, rainbowfishes, hardyheads, mouth almighties, grunters, gudgeons (especially the genera Oxyeleotris and Mogurnda), along with gobies, with many of the genus Glossogobius. In the upland lakes, the highest one to hold fishes, Lake Tage in central Irian has but one native species, a gudgeon, Oxyeleotris wisselensis. Carp have recently been introduces there. Of the 13 species in highland lakes, 11 are endemics.
If we look at the location within the water column, about half of the fishes in New Guinea live near the bottom. The gobies and gudgeons spend most of their time directly on the bottom while the catfishes actively swim just over it, finding meals with their sensitive feelers. The other half of the fishes swim or hover well above the bottom. These include predators like barramundi and grunters, hovering gudgeons and the more active herrings, rainbowfishes, hardyheads. The halfbeaks stay close to the surface.
While not unique to New Guinea, the bull shark can be found long distances inland from its usual marine habitat. The species, Carcharhynus leucas, is a heavy-bodied animal with a short snout. It has been held responsible for a fair number of human deaths elsewhere but none recorded in New Guinea. In the Atlantic, this shark has been spotted 3700 kilometers up the Amazon. In New Guinea there are records of the shark in the Sepik and Ramu Rivers as well as (formerly) in Lake Yamur. In the Kamoro area of the south-central coast, this shark used to be a frequent visitor in rivers dozens of kilometers from the sea but the use of nets has now kept them out of this territory for the past two decades. The sawfishes of the Pristidae family met the same fate. These are shark-like, especially in the shape of their fins, but are physiologically much closer to rays as seen by their ventral gills. One New Guinea species, Pristis macrodon, attained lengths of over 4.5 meters and were found in turbid channels or large rivers with soft mud bottoms. Large individuals were formerly reported from the Lake Sentani area where they received some protection from the indigenous religion. But Christianity and nets have wiped them out there.
The forked-tailed catfishes of the Ariidae family have 80 species world-wide, of which Australia and New Guinea hold over half, at 43. The eggs, few in number, are incubated in the mouth of the male who cares for the young also in its mouth. They are among the most frequently caught fishes by the Kamoro on the south coast, the fatty fishes making a perfect combination with the starchy sago staple. The largest species of ariids here, just being scientifically described, measures over 1.2 meters. The eel-tailed catfishes, of the Plotosidae family, are usually found in brackish or estuarine waters. However, in both Australia and New Guinea numerous fresh-water species have evolved. The most common genus in this family, Neosilurus, has 11 species, including four from Australia, five from New Guinea and two shared species.
Some cardinalfishes and mouth almighties also are mouth-brooders, like the ariids, but one family, the Kurtidae, employs a different body part for the same purpose. The males feature a prominent bump on their foreheads’ occipital bone, sprouting a curved hook-like protuberance. This appendage is used to carry the grape-like cluster of eggs until hatching time. The Kurtus gulliveri is found in south-central New Guinea as well as in the northern Australian mangroves, brackish estuaries and slow-flowing, turbid rivers.
The most prized fish of them all, the barramundi, also called many other names or, more precisely, Lates calcarifer, belong to the Centropomidae family of giant perches. These fishes, along with the freshwater eels, hold to a catadramous life-cycle, meaning they live in freshwater as adults and go out to the shallow sea (two to three meters) to form spawning aggregations at specific locations from October to February. Some males undergo a natural sex change to become the largest females which can reach 1.8 meters and weigh some 60 kg. In New Guinea, the species is confined to the south-central coastal and inland areas.
The rainbowfishes, of the Melanotaeniidae family, form a group of seven genera split into 68 species. There are four genera in Australia and five in New Guinea. The Melanotaenia and Iratherina genera are shared by the two regions. Three of the southern New Guinea species are shared with Australia. These schooling fishes are found in most watery habitats below 1500 meters, shoaling in large groups near the surface. The various species are distinguished by their bright patterns which flash when in a sexy mood. (This characteristic is shared by the related Blue-eyes.) Aquarists favor rainbowfishes for their placid nature and easy of breeding in captivity.
The most prized aquarium fish, the arowana, belongs to the Osteoglossidae family, called Bony Tongues, which are an ancient group of primarily freshwater fishes. In western Indonesia, the main species sought is Osteoglossum bicirrhosum, with different colors, with the golden ones thought by the Chinese to bring good luck and fetching prices of over $500. In Irian we have a species commonly called saratoga, Scleropages jardinii, enjoying theoretical legal protection. The fish inhabits relatively still waters of streams and swamps around Merauke and has been (unreliably) reported from the Lorentz National Park. In Australia, the adult of the species is respected by anglers for their fighting ability and caught for the tasty flesh.
Two other fishes merit mention: the archerfish which aims a very accurate get of water onto insects up to three meters away, devoured as it hits the water. There are six species of these, of which two are relatively wide-spread. There are also ‘walking’ gobies of the genus Periophthalmus which can spend long periods out of the water and even climb up trees a short way in search of insects. There are 12 species, widely distributed in the Indo-Pacific, found on mudflats and mangrove swamps. While they quickly scamper into the water when a boat approaches, as soon as they feel safe they come out again offering a fun mini-spectacle of males raising their dorsal fins to attract females and to compete with other males trying for the same sex objects.
VIII. Frogs and toads: the amphibians
Frogs and reptiles are sometimes classified together under the term herpetofauna, from the Greek root word meaning ‘crawling’. Curiously enough, the Indonesian words for these animals, ‘binatang melata’, means ‘crawling animals’, but only snakes and a few lizards qualifying as true slitherers. Some zoologists are none too happy about the term herpetofauna, as no has tried to group fishes and amphibians into a single word (icthybians?). The lumping of the two classes might stem from the fact that reptiles evolved from early amphibians and both groups are ectothermic (cold-blooded).
Herptiles are united by several common features: their body temperatures depend on that of their environment and some can change color by altering the shape of their color pigment cells. This feature serves to signal mood, readiness for sex, the need to blend into the background and perhaps a reaction to temperature. Compared to amphibians, most reptiles are much less dependent on water. Their skin scales minimize water loss and do not play as important role in respiration, as with most amphibians.
The ancestors of most groups of New Guinea reptiles and amphibians came from the west. A few arrived from Australia, across a land bridge which become the Arafura Sea. In this second group we have the frog families Hylidae and Myobatrichidae (formerly Leptodactylidae) and the turtle family Chelidae. Many have become New Guinea endemics. These three families also have close relatives in South America, pointing out their common origins in Gondwanaland.
As with most other animal groups, the herpetofauna of Irian is poorly known. Until recently, there were only 329 species listed, as compared to 505 for PNG. Many areas in the western half of the island remain completely unknown. These include the Foja, Van Rees and the Fakfak mountains, along with the Wandamen Peninsula. Some very recent surveys are helping to fill this gap, but there have been no recent publication that synthesize the current state of knowledge of Irian’s herpetofauna. We are still dependent on three then-comprehensive but now much outdated works published under the auspices of the Amsterdam Museum: de Rooij’s 1915 and 1917 treatment of reptiles and van Kampen’s 1923 work on amphibians.
The crucial step in evolution: water to land
Amphibians evolved, thanks to lungs and limbs, starting some 360 million years ago, to become the first vertebrates to colonize land. Their ancestor was a fleshy- or lobe-finned bony fish called a sarcopterygian. The fish belonged to a group with limb-like bones and primitive lungs supplemented their gills, allowing breathing out of water as well as under the surface. These ancient fishes have a relative still alive today, the Coelacanth, which some thought were the direct ancestors of all four-limbed creatures. However, this belief is erroneous. But these recently re-discovered fishes, thought to have become extinct well over 60 million years ago, have lobed fins which are similar to the ones which in the sarcopterygians, evolved to become the four appendages of all land animals, collectively called tetrapods.
The coelacanth was first promoted as a ‘missing link’ between fishes and land animals. But the link is more with a former grouping called crossopterygians, lobe-finned or tassel-finned fishes. There were three major divisions within this group: one contained primitive orders of fishes such as the coelacanths, an extinct group called rhizodontids and the the rhipidistians, a specialized subgroup which includes forms having a strong pectoral fin with bones similar to those found in tetrapods: the humerus, the ulna and the radius. More recent classifications now place the coelacanths in the Order Ceolacanthiformes, which, along with two lungfish orders made up the subclass Sarcopterygii. Be that as it may, the primitive fishes’ fins which evolved into arms and legs already had the same bone pattern found in all land animals. And the swim bladders of the rhipidistians evolved into air-breathing lungs. The evolution from finned, gill-breathing fishes to air-breathing, land-walking animals was the most important step in vertebrate evolution. Amphibians were the first step in this process. Then, within a relatively short time after the first amphibians began to diversity, and the first proto-reptiles appeared, in the Early Carboniferous. The rest of vertebrate evolution is simple by comparison, being merely a tale of what lineages stemmed from the basic reptilian pattern.
The evolution of the hard-shelled egg and amniote egg which contains an embryonic sac called the amnion, was the greatest single advancement in the evolution of vertebrates from fish to human. The fluid in this sac provides the necessary liquid environment so that animals can reproduce on land: all of the early (and very long) evolution of life took place in water and all land animals still require this milieu for their embryo. The amniotic egg enabled the early tetrapods to venture away from the seas, rivers and lakes, and to seek new inland habitats. After the embryo stage, water remains the largest component by far in animals’ bodies.
By end of Triassic, about 200 million years ago, nearly all of the large (up to six meters!) ancestral amphibians were extinct. Today’s amphibians as well as the amniote tetrapods (birds, reptiles and mammals) originated from different early amphibians. The subclass Lissamphibia, the modern tailed amphibians (plus their direct ancestors), appeared during the Triassic period and this is the only amphibian group that has survived to the present. The fossil record unfortunately has been insufficient for a proper understating of the ancestry of the modern amphibians. But it has been established that the frogs (Order Anura) and the caecilians (worm-like amphibians of the Order Gymnophiona) both date back to the early Jurassic, some 190 million years ago. The salamanders (Order Caudata) first appeared later, in the middle Jurassic, between 170 and 150 million years ago. These three groups have outlived the early world-dominant amphibians, several periods of reptile dominance as well as mammalian extinctions.
With the recent discovery of many new frog species, there are now more described amphibians than mammals. The latest current amphibian count hovers around 5000 but it is likely that there are still several hundred species of frogs waiting to be added to the list. Amphibians range from the saline environment of the mangrove swamps to almost deserts and to the summits of 4000-meter high peaks. Over 80 per cent of the species are found in the tropics, with almost half (44 per cent) in the tropical zone of the Americas. Because amphibian eggs lack a water-resistant shell, the greatest diversity of reproductive modes occurs in the humid tropics where the eggs can survive long periods in the permanently moist terrestrial environment.
Amphibians are divided into three major groups but here we cover only Anurans (frogs and toads), as the other groups do not exist in New Guinea. Species of the Order Caudata, the newts and salamanders, occur no further east than the Malaysian Peninsula and the worm-like burrowing amphibians of the Order Gymnophiona (or, Apoda) extend eastward only to Borneo and Java.
The word toad must be used with caution around frog experts: it is not a precise term. Most laymen mean frogs with warty skins when using the word toad but most experts restrict the usage of the term to the (very warty) Family Bufonidae, which is not native to our area, having been introduced in the 1930s in a misguided attempt to control insect pests. Plenty of other frogs have warty skins but better not refer to them as toads if there is a herpetologist within earshot as you might be in for a scientific scolding.
The Order Anura is made up of some 4200-odd species of frogs and toads. Four of the five diverse frog families, the Hylidae, Ranidae, Bufonidae and Microhylidae are found across several continents attesting to their successful dispersal. The most diverse family of all, the Leptodactylidae, with 22 per cent of the living frogs, is found only in South and Central America. Of this family, the genus Eleutherodactylus, is the most diverse vertebrate genus on earth, with more than 550 species. One of the South American frogs, Epipedobates tricolor, is covered with skin containing aptly named epibatidine, a chemical which blocks pain 200 times more effectively than morphine. Another species, Phyllobates terribilis, owns toxic skin compounds with enough punch to kill several adult humans. This asset is put to good use by being smeared on blowgun dart used by the Choco Indians. In our area, a new family, the Myobatrachidae, has recently been accepted to hold the Australian and New Guinea species of the family Leptodactylidae.
What is special about frogs
Frogs differ from other terrestrial vertebrates in their wide range of life histories and modes of reproduction. Female frogs lay large numbers of eggs, but then put in only a small investment in each. With the high number of eggs per clutch, the population can increase very fast when conditions are right. Evolution has led to an anuran trend toward removal of eggs and larvae from the aquatic environment. And frogs that need to breed outside water have evolved a startling array of reproductive adaptations, the widest range of any tetrapod: aquatic eggs and larvae, terrestrial eggs and truly viviparous (bearing live young) species where mom provides nutrition in addition to the yolk during development. Fertilization is external, and the eggs are covered by thick gelatinous capsules. (Reptile eggs are much better protected by a hard shell. This is the main factor which allowed them to out-compete amphibians and rule the earth during the long Age of Reptiles.)
Anurans are short-bodied, without tails, looking on the world with large, bulging eyes. They are characterized by well developed hind legs designed for hopping. Large eyes for feeding and keen ears for territorial claims and potential sex are their most important sense organs. Most of the males use vocal sacs with species-specific sounds, signal their presence and to attract mates. This vocalization also announce their status to other males. Each species has specific calls, with variations in the dominant frequencies, pulse rate and duration usually reflecting body size as well as location. Females respond only to the specific calls of the males of their own species.
The anuran life cycle requires an aquatic stage for many species, with the larval tadpoles metamorphosing into adult frogs. This process involves numerous body changes, gills becoming lungs, resorption of the tail and the sprouting of limbs. Tadpoles lack limbs on hatching. Some spend up to 3 years as larvae, but usually much less. Tadpoles are microphagous (eating tiny bits) herbivores, feeding on algae and small parts of higher plants. Most also feed on animal bits and pieces, when available: scavenging dead animals in water and preying on amphibian eggs. Adults are almost entirely carnivorous, gobbling down anything living small enough to fit into their mouths, usually a wide variety of insects. Prey is has to be swallowed whole as they lack teeth. Frogs are either sit-and-wait predators, relying on vision or active foragers, using olfaction for prey location. Photoreceptors of several types, probably allow at least limited color vision.
Most amphibians’ skins are not water resistant, thus they require moist conditions to prevent desiccation. Gas exchange takes place across moist skin as well as in the lungs. Frogs are ectotherms, relying on external source of body heat. All aquatic forms and many terrestrial ones also poikilotherms with body temperature the same as the environment. Basking to raise body temperature is limited by the need to conserve water. Anurans as a group can tolerate wide range of temp and water availability, ranging to all but highest altitudes and driest deserts.
All modern amphibians have complex glandular skins and most lack scales. Their skins are kept moist by secretions from mucus glands, whereas granular glands produce a variety of toxins to deter predators and perhaps microbial infections as well. Frogs can alter shape of their skin pigment cells, thus rapidly change color. Frog hearts typically hold three chambers: two atria receiving blood from body and lungs and one ventricle to pump blood to the lungs and the rest of the body.
New Guinea frogs
The only comprehensive work on frogs in this island was by P.N. van Kampen who in 1910 spent several months in northern New Guinea. In 1923 he published the Amphibia of the Indo-Australian Archipelago, the only publication that has dealt comprehensively with the frogs of the region. However, the work is outdated, and retains very limited use now for species and even generic identifications. In 1976, J. I. Menzies published the Handbook of Common New Guinea Frogs, focusing on the eastern part of the island and covering about one fourth of the 200-odd species known at the time. For identification purposes, Menzies recommended memorizing the calls of the different species, as many New Guinea frogs are easier to hear than to see. Furthermore, many closely related species can only be distinguished by their voices. Unfortunately, the calls of very few Irian species are known, so this technique is of limited use. Menzies also underlines that New Guinea is a major center of frog evolution, especially for the arboreal hylids and mycrohylids, many of which are hard to distinguish from each other.
In general, we know that some two thirds of the frogs in New Guinea are descendants of ancestors from south-east Asia, with the remaining from Australia. One species, the cane toad, Bufo marinus from the Family Bufonidae, was introduced from the Americas to Australia in 1935, and then to New Guinea in 1937 along with the rest of the Pacific in a misguided attempt to control the sugar cane weevil and other agricultural pests. The vaunted Bufo was no better than native frogs at pest control. And it now thrives in New Guinea, a particularly nasty customer, given its voracious appetite. This toad is also one very large amphibian, with adult females reaching a whopping 200 mm. It has no natural enemies in New Guinea: as with all toads, it has poison glands in the skin. The reproductive rate is so high that Menzies writes that ‘the density of population has to be seen to be believed’. Fortunately, the beast is confined to the PNG side where it feeds on insects but also on the young and adults of various vertebrates. It has been accused of drastically reducing the numbers of some grassland snakes in areas where it thrives. There is now a second species of this awful genus, Bufo malanosticus, which has been introduced into New Guinea, and is now common in Manokwari on the north-west coast of Irian Jaya.
In areas of high humidity, such as New Guinea, many frogs lay their eggs out of the water, so there is no tadpole stage in the life cycle. There are four frog families indigenous to New Guinea: the myobactrachids and the hylids, which do have tadpole stages, the microhylids which do not and the ranids, some of which do (Rana spp.) and some which don’t (Platymantis spp.). The hylids and the myobactrachids are from Australia, the Gondwanaland component of New Guinea Anura. The ranids and microhylids are from Asia, having island-hopped over to New Guinea, probably on floating vegetation.
Well, that’s the general picture, but local frog realities are not so simple. While it is accepted that the ranids did originate from south-east Asia, some do and some don’t have tadpoles. Also the microhylids in Asia do have a tadpole stage. The groups in New Guinea have lost the tadpole stage, whether their ancestors came from Asia or Australia. At any rate, many frogs from south-east Asia traveled beyond New Guinea, and there is a diverse group of ranids that have evolved in the Solomons. Very few were able to establish themselves in Australia as the shores near New Guinea did not offer the proper ecological setting (too dry) for them to survive and thrive.
Let’s take a quick overview of New Guinean frogs. A recent (1997) count came up with 98 species (out of a current total of 329 amphibians and reptiles) for Irian while in PNG the frog count is now over 200 (and 510 total herpetofauna). Irian has much fewer endemic frog species than PNG, 30 per cent versus 60 per cent. Irian has no endemic genera, while PNG can boast of four. Museum specimen from PNG outnumber those from Irian by at least 15 to one (Allison and Dwiyahreni, 1997). This is due to the paucity of collections in Irian. While many have been carried out in PNG, relatively few major collections have been made on the western side of the border. Perhaps the most significant of these were the ones by Lorentz (1907 and 1913), the British Ornithological Union (1909/1910), Wollaston (1912/1913) and the third Archbold Expedition of 1938/1939. Just how little the amphibian fauna has been studied in Irian can be gleaned from a recent rapid survey in the Wapoga area where Steve Richards and Djoko Iskandar increased the known number of Irian’s frog species by 30 per cent(Richards at al., 2000). They wrote that undoubtedly many more endemic species are waiting to be found in the mountains of Irian.
A fascinating topic for future research would be an ecological analysis of Irian’s frog fauna in comparison with Australia’s. For some still not well understood reason, perhaps a chytrid fungus (Batrachochytridium dendrobatoides), several species of Australian frogs have completely disappeared since the late 1970s and early 1980s. We know that frogs are a most useful tool as monitors of the health of the environment. The highland and stream-dwelling frogs of Irian and Australia are ecologically and phylogenetically related. The few populations that have been examined in Irian are healthy and vigorous. Have they remained isolated from whatever is causing the population declines in Australia?
A look at the frog families in New Guinea shows that the hylids (2 genera, 39 species in Irian) are mostly tree frogs. Almost all are blessed with expanded suction pads on their fingers and toes, making them efficient climbers. The hylids vary greatly in shape and preferred habitat. The ranids (3 genera, 13 species in Irian) are considered the ‘true frogs’, very abundant almost everywhere, except in Australia. There are three genera in New Guinea (Rana, Platymantis and Limnonectes) with several species, including the introduced Rana cancrivora, a crab-eating mangrove frog. The microhylids (12 genera, 39 species in Irian) live and love mostly in tropical eco-systems. All New Guinea species lay eggs out of water and hatch into fully formed frogs, with no aquatic tadpole or larval stage. In some species, the hatched young are carried on the back of a parent for some time for protection.
Microhylids reach their greatest development and diversity in New Guinea. Of the two endemic sub-families, the Asterophryinae are only found in New Guinea and the Moluccas while the Genyophryninae range from the southern Philippines to Australia, with the most diversity found in New Guinea. Both of these sub-families, along with the ranid genus Platymantis, show a very non-frog-like reproductive strategy: no tadpole stage needed, with the direct development of the little frogs within the egg until ready to hatch and face the world. The fourth and last family found naturally in New Guinea, the Myobatrachidae (3 genera, 5 species in Irian) are only found in New Guinea and Australia. This last group, along with the hylids, are of Gondwanaland origins and dominate the Aussie frog fauna.
The microhylids are a large group, found in tropical and warm to temperate climates in other parts of the world. The New Guinea species make up the most diverse family of frogs on the island with a fascinating range of life-styles. Some burrow and some live in trees, while others live on the forest floor or in streams. They make up just under half of the species (about 90 out of just over 200) in New Guinea, split among 13 genera in Irian (out of a total of 18 for this family and 28 for all frogs on the island). This group is not closely related to the hylids as the name implies and are not necessarily small as the prefix micro suggests. There are two subfamilies, the Asterophryinae (34 species) and the Sphenophryninae (50+ species) both of which reach their greatest diversity in this island. The family Microhylidae shows considerably morphological variation and live in a wide variety of habitats ranging from underground to the tops of trees and from the lowland rainforest to alpine grasslands. Some species appear to be quite restricted in their range, and previously unknown ones are being discovered as new areas are explored by frog specialists. The group presents difficulties in identification as complexes of closely related ones can only be separated by their particular calls, and here the differences are so slight as to make it a tough task to define separate species.
This frog family can not be considered amphibious in the literal sense of the term as, thanks to their method of reproduction, it has freed itself completely from the water milieu. The eggs, laid on moist land, enclose an embryo which develops directly into a miniature frog, skipping the tadpole stage. But this freedom has a price. It requires that females lay large, yolk rich eggs, so few can be laid at any one time, unlike frogs breeding in water. The eggs are usually guarded by the male and in some species parental care goes further: froglets cling to the back of the parent for quite a long period after hatching. Living on land means that swimming aids are no longer required, although webbing can help in climbing and leaping. By that as it may, none of the mycrohylids have webbed fingers and only a few have vestigial toe webbing.
The croaking of microhylids overwhelms other sounds in some forest areas but it takes well-trained and tuned ears to pick out the species. Field classification based on morphology is even more difficult because many species can be identified only by the variations in their muscles and skeletons. This is true even at the genus level. Family members range in size from about 10 to 100 mm. Knowing the habitats of the various genera and species can be of great help in trying to find these beasts. New Guinea microhylids ignore the normal aquatic frog habitat, occupying a broad range of ecosystems. They can be grouped into four main life-styles:
1. Burrowing (technically called fossorial habitat) is not just a way to shelter but a way of life for some of the Asterophryinae. Their bodies are well adapted to this, with obese bodies propelled by very short limbs, a small, pointed head with projecting snout. These animals are tough to find and little is known about them.
2. Surface dwellers hide in the forest floor litter during the day, not a bad idea, with lots of predators around. It’s a lot safer to come out only at night to feed or to seek sex. Their bodies are quite fat, like their fossorial relatives, with a broad head (blunt or pointed), large eyes, short to medium sized limbs, tipped by fingers and toes which sometimes end in disks. Two species stand out: Oreophryne brevicrus likes to live high, up in the alpine grassland to over 3800 meters, not your usual frog habitat. Asterophrys turpicola is a frightful looking customer: according to Menzies this bizarre critter ‘once seen is unlikely forgotten’. The body is fairly large and long for a microhylid at 65 mm. The head is very broad, fronting a rounded body with short limbs and warts on the flanks. Our beast features several prominent spikes on its upper eyelids and two more below the chin, weird enough to induce nightmares if large enough in your dreams.
3. Climbing frogs (sometimes called scansorial, meaning climbing, but not too high) wisely spend the daylight hours out of sight under leaves or low vegetation, coming out on the low vegetation (one to three meters high) at night for their various activities. Their large eyes enhance their nocturnal vision, while fingers and toes end in large disks for climbing.
4. Arboreal frogs are similarly built to the climbing ones, even if they do go higher. They seldom come down to earth, preferring to stay in the crowns of the high forest, thus frustrating terrestrial predators as well as biologists. Not so incidentally, they specialize in gobbling the insects living in the upper parts of trees. One of them, Oreophryne anthonyi, lives and breeds in water-holding epiphytes, as well as in the high leaves of the pandanus plants. These are safe, moist environments to lay eggs. There are probably plenty of new species to be discovered in New Guinea in this high tree dwelling category for zoologists able to climb trees. The genus is widespread, from the Philippines to New Guinea and New Britain. It reaches its greatest diversity on mainland NG and nearby islands, with 14 species. A newly discovered species, Oreophryne minuta has tiny males reaching only 11.5 mm and lacking expanded terminal disks on their fingers and toes.
This group of frogs are the most abundant in the world, except in Australia. The family traces its ancestors to the west of New Guinea. On the main island, there are three genera: Rana, Platymantis, and Limnonectes. Compared to the microhylids, this family show much less diversity in habitat use. Most feature narrow head, pointed snouts and eyes directed to the sides. The majority of the genus Platymantis genus are terrestrial, and all are independent of aquatic habitats. They show two of the same evolutionary adaptations as the microhylids: direct embryonic development, the key to their success in spreading to the ample new terrestrial habitats across salt water. But for some reason, species did not proliferate in New Guinea, as did the microhylids. The ranid genus Platymantis lack of toe webbing and are primarily terrestrial. They are found from the Philippines to New Guinea and the Solomon Islands and Fiji, but their center of diversity is the Philippines. None made it to Australia and the genus on mainland New Guinea contains 19 species, with over half of these identified since 1965. (Beehler, 1993)
The other genus, Rana, is also found outside the Australian-Papuan region. It has some 20 species in New Guinea where they proliferate in the lowland aquatic zones, with ‘normal’ aquatic eggs and the tadpole stage of the normal prototype of ‘normal’ self-respecting frogs world-wide. All of them descend from ancestors in the west, are long-legged, with bodies ranging in length from 24 to over 160 mm. The owners of the longest bodies are the giant Arfak river frogs, Rana arfaki. This is the largest species on New Guinea, seldom seen but much sought after for meals. It lives along river banks to 1000 meters altitude and feeds on crabs and prawns. Other species live even higher, some not found below 1400 meters. In this western part of the island, there are three genera and 13 species. The family is virtually absent from Australia, with only one species, Rana daemeli, found there and in New Guinea, a recent colonizer of the Cape York Peninsula. There are at least 14 species of the Ranidae family in New Guinea.(Beehler, 1993)
With only two closely related genera (Nyctimystes and Litoria) but over 70 species in the NG region, the hylids are a close second to the microhylids in species diversity. They are poor at getting across stretches of sea water, but once they made it to New Guinea, this mostly arboreal family speciated extensively. Some species are long-limbed with only slightly expanded pads and these are terrestrial. However, many more are blessed with large finder and toe pads. These critters like climbing trees, but they need water for laying their eggs and for the tadpole stage. The genus Nyctimystes as well as a few Litoria have adapted to swiftly flowing mountain streams, while most Litoria breed in still or slow-moving waters. While most Nytimystes and mountain stream Litoria call to their potential breeding partners from low trees or shrubs along streams or rivers, they often wander away from running water. All our hylids feed on a variety of insects and both New Guinea genera are also found in Australia. New Guinea has at least 16 endemic species.
This genus Litoria, with 59 species in New Guinea (with 34 in Irian; Australia is home to 62 species of which 9 are shared with New Guinea), has representatives with many different life-styles: some are terrestrial, some arboreal (living high in trees) and some scansorial (spending lots of time on low vegetation). The species on the island include some of the smallest as well as the largest family members. Bodies which can be quite large but slender, along with long limbs tipped with suctorial disks are evolutionary responses to the climbing and arboreal life-style. Australia has a somewhat less species than New Guinea, with at least nine shared between the island’s south and the continent’s north. The genus reaches its greatest diversity on mainland New Guinea.
The Litoria bicolor group includes species found in the open, grassy swamps of both north and south coasts. About the only way to differentiate them, aside from drastic surgery, is to listen to their individual mating calls. With a body length of 20 to 30 cm., these are among the smallest hylids but quite obvious in their open country habitat: bright green backs and pure white bellies. When the thighs open, they reveal bright orange or red colors. They are also characterized by a conspicuous white stripe running from below the eye and ending at the groin.
The species Litoria infrafrenata also shows beautiful bright green color. The individuals are among the largest tree frogs in the world, reaching 135 mm. Menzies writes that ‘they sit under lights to catch insects and are not disturbed by passing people, even allowing themselves to be picked up without panicking. Our friendly frog shows a conspicuous white stripe on the lower lip, extending back to the ear region. The mating call is a dog-like bark. The species is most common in the southern New Guinea lowlands, but also in the north as well as some adjacent islands.
Members of the genus Nyctimystes are tree frogs, some green, some brown, of varying size, with N. humeralis reaching 100 mm. Their habitat is mostly montane with only one small group living at low altitudes. Some species sport vivid white camouflage spots resembling mold. Some of the green hylids of both genera reflect near-infrared. The genus Litoria occurs at all altitudes, being exceptionally abundant in the lowlands. The genus includes two terrestrial species here, not keen on climbing trees. Others in this genus include quite a variety in size, coloration and habitat: small green tree frogs, large green tree frogs, small and medium brown tree frogs and torrent-breeding ones. This genus has 25 currently (1997) recognized species, with three restricted to the forests of north-east Australia and the rest endemic to New Guinea. So far, only five species, including two endemics, have been found in Irian.
This family, which is restricted to the Papuan-Australian area, includes five genera and only seven species in New Guinea (five in Irian, six in PNG), but shows plenty of morphological, ecological and life-cycle diversity. The finger and toe disks are small or absent so none are primarily arboreal. The toes are never more than partially webbed. These frogs are confined to the ground (some burrow) or swamps. Some species favor a habitat near waterfalls or swiftly flowing creeks and streams. Egg and larval development range from fully aquatic to completely land-based. The species of the genera Limnodynastes and Lechriodus lay their eggs in a foam ‘nest’ that floats on water. The other genera, Crinia, Uperoleia and Mixophyes have no use for this type of nests. The ground-favoring life-style is confirmed by their unwebbed fingers and little if any toe webbing. Although there are few myobactrachids in New Guinea, they represent many of the genera known from northern Australia. Only one species, Lechiriodus melanopyga, can be encountered fairly commonly. It lives in the woodlands and dry forests in a north-south band from the Lower Fly and Digul River plains north to the foothills of the central cordillera. They are quite inconspicuous, medium sized and dull brown. None too exciting of a critter. All the New Guinea myobatrachid genera and three of the species are also found in Australia which has a richer fauna in this family. (??? Cogger only has one Crinia remota and Limnodyastes convexiusculus as shared species...???) Two of the Australian genera show pretty unusual care for the young which develop in a groin brood pouch of the males of Assa genus and in the stomach of the Rheobatrachus group.
IX. Lizards, snakes, turtles and crocodiles: the reptiles
Reptiles evolved from a group of early and now extinct amphibians. They reached their glory some 120 million years ago, during the Mesozoic Period (the Age of Reptiles) when this group was at the peak of its diversity. At that time, reptiles dominated the land, the sea and the skies with an almost endless varieties of forms. Most of these have died out, including the famous dinosaurs, around 65 million years ago. The large dinosaurs might have been endothermic, with the ability to keep body temperature constant, as today’s mammals and birds. But the descendants of the smaller reptiles which survived the dinosaur extinction are all ectothermic. They have no physiological mechanism for producing the large amount of metabolic heat necessary to maintain a constant body temperature whence their reliance on the environment to heat their bodies. Less food is thus required but the price to pay is sluggish performance when the ambient temperature is low and basking in the sun is required to bring the body up to speed.
The ability to live and reproduce out of water made the reptiles the first group to successfully colonize exclusively land-based ecosystems. Reptiles also practice ‘safer sex’: internal fertilization, laying eggs with thick, leathery shells for protection. The young emerge as miniature adults, ready to take on the world with a healthy, inbred fear of predators, sometimes including their own fathers. Some reptiles are viviparous, bearing live young, with the motherly instinct present to protect the young.
Many reptiles have developed the ability to retain water, perhaps the most important physiological mechanism for land based life. The skin is fairly waterproof and plays no part in respiration, as in the amphibians. Nitric wastes are excreted as uric acid pellets or powder, retaining and re-absorbing the water content while the wastes are in the cloaca before excretion. This water conservation allows reptiles not only to live on land, but also to colonize dry, arid ecosystems. In their eating habits, reptiles run the whole gamut, from herbivorous, to omnivorous to exclusively carnivorous.
In the Class Reptilia, we have three orders: Squamata (snakes: suborder Serpentes and lizards, suborder Sauria), Testudinata (turtles) and Crocodylia (crocodiles). Snakes and lizards make up some 95% of the reptiles alive today. Lizards, unlike snakes, have well-developed eyelids and external ears.
All living reptile groups are found in New Guinea are found in New Guinea, except for the Order Rhynchocephala, with a single surviving species, the tuatara (Sphenodon punctatus) now living only on some small islands of the Cook Strait in New Zealand. The other species of this group became extinct some 100 million years ago.
For just the PNG side of the island, Beehler (1993) lists 13 species of turtles, 195 lizards and 98 snakes, along with two crocodiles, to which one will very probably be added as the southern fresh water animal seems different from its northern cousin.
While most snakes and lizards are easy enough to tell apart, there are two families which have limbless, snake-like bodies. A few skinks are limbless but it is the Family Pygopodidae, the lizard-snakes which can confuse the uninitiated. While closely related to geckos, the lizard-snakes, with two species in New Guinea, resemble snakes. That is if you ever see one, which is highly unlikely. Should you ever find one, take a look to see if it has a small ear opening just behind the eye: if it does, it’s a lizard as snakes lack this feature. In fact this is what makes a lizard a lizard, along with limbs and a tail as long (or longer) than the snout-to-vent length. And moveable eyelids. In snakes, the tail is only a fraction of the body length, but then again, how can you tell where the body ends and the tail starts? Only dissection can provide a sure answer. Other lizard-snake differences include moveable eyelids in lizards, absent in snakes, the lizards’ rigid jaw with the mandibles fused at the chin versus a flexible, unfused and articulated jaw (which allow snakes to swallow huge prey), the lizards’ unique capability of voluntary tail loss and regeneration, the fact that very few lizards are poisonous while lots of snakes have this charming defense mechanism.
Lizards in New Guinea are the least known of the four major order of reptiles. While there have been studies of various groups of lizards, no one has bothered to bring it all together for scientist or layman. In fact, the only general work which includes Irian was written in 1915 (and reprinted in 1970), Nelly De Rooij’s Reptiles of the Indo-Australian Archipelago. While many new species and even genera have been re-named and added, the work retains much of its original value - as there is nothing else. Monitor or varanid lizards, thanks to their large size and limited number of species, are covered in several books which deals with the single-genus family on a world-wide basis. For the other main lizard families found in New Guinea, the geckos, the skinks and the agamids we have only scattered scientific literature with very little in the way of pictorial identification aids. And while these families are well covered in Australian literature, including excellent illustrated works, many of the species are different from those found on our island.
Lizards are reptiles (Class Reptilia) and, along with snakes, grouped into the Order Squamata. The reason for the lumping is the close relation between snakes and lizards and the meaning of the name squamata is based on their most obvious common characteristic: scaly bodies. Thus both groups are ‘scaly reptiles’. There are about 300 species of lizards in the world, characterized by moveable eyelids. They have adapted to a wide range of habitats and methods of locomotion which include gliding, swimming, running, climbing, creeping and burrowing.
Today’s lizard fauna of New Guinea and nearby islands includes six families, all descendants of migrants from the west and all moving on to Australia as well via New Guinea. These families are the Agamidae, Dibamidae, Gekkonidae, Pygopodidae, Scincidae and Varunidae. The lizards on the island are split into 33 genera with just over 200 species with very probable additions likely after more field research. Our lizard fauna closely resembles that of Australia, with skinks dominating both geographical entities: 54% of the Australian and 71% of the New Guinea species. The main difference comes from the far greater number of wide-spread and Asian lizards in New Guinea. Australia can boast of a far greater percentage of endemic species: 93% of its lizard population, versus only about 60% for New Guinea. (By comparison, snakes species are only 33 per cent endemic to New Guinea.) On the genus level, both areas have about the same percentage of endemics. Some of the island’s lizards are quite recent arrivals to the east and south, as for example the agamid genus Hypsilurus which has but two endemics in Australia but 15 in New Guinea and the islands running west to the Wallace Line. Gondwana lizard groups are also relatively recent arrivals to New Guinea.
The New Guinea agamids are grouped into six genera, split into 24 species (13 in Irian) with all genera also present in Australia but hardly any of the species. The family Gekkonidae are represented on the island by eight genera and 32 species (23 in Irian). The Pygopodidae, a snake-like lizard family related to geckos, has but one genus and two species. The largest family on the island, the Scincidae are grouped into at least 18 genera (14 in Irian) with 137 species. In Irian, these skinks make up 87 of the total of 132 lizard species so far reported from the western half of the island. In all of New Guinea, two skink genera predominate: the Emoia and the Sphenomorphus. These are morphologically quite diverse and are due for a split into better defined genera as soon as some qualified scientist obtains the finances, permits and the time to perform the job. Eight species of varanid or monitor lizards have been recorded for the eastern half island, with seven in the west.
In New Guinea, the lizards do not follow birds and plants in increased endemic species richness in relation to higher altitude. Lizard species decline with altitude due to fewer habitats to exploit. This is due to the fact that lizards as a group have evolved for adaptation to warm weather. Only a few have specialized in higher altitudes and latitudes. But while there is gradual decline in tree lizards from the lowland to midmontane forests, we find an increase higher up. Here most lizards are live-bearers, due to the fact that the ground is too cold for egg development.
Several lizards merit special mention. These include the Varanus salvatorii which reaches four meters in length, making it the longest lizard in the world. (Not quite so long, the Komodo dragon, Varanus komodoensis, has a much bulkier body.) New Guinea has the only lizard, in fact the only anmiote, with green blood pigments: genus Prasinohaema. A lizard of the genius Tribolanotus, a small terrestrial skink, sports bony projections, creating an uncanny resemblance to crocodiles. water lizard with ‘sail’ - an Agamid with erectile crest???
These legless lizards, related to the geckos, are grouped into eight genera and some 30 species in Australia but one genus and two species have so far been found in New Guinea. And one of these species is shared with Australia while the other is endemic. The pygopodids are tough to study as they are secretive and not a very exciting group. Their eyes are lidless, like snakes, and not all have an external ear opening, the usual way to distinguish lizards. There are probably more species in New Guinea, but dedicated (and financed) biologists are needed to make possible additions to the very short list. This is the only reptile family endemic to the Australian region. Australia shares one of its widely distributed species with New Guinea, Lialis burtonis (Burton’s Snake-lizard). Another species, Lialis jicari is found only in New Guinea.
The geckos are the most familiar group of lizards, with several genera having members living in close proximity to humans: on wall or on ceilings throughout tropical and warm-temperate regions. They have well developed pentadactyl (five digits) limbs. But how they can keep a grip on the smoothest of surfaces required high magnification which showed flattened fingers and toes with dense mats of hair ending in hooks, like velcro. This is enough to allow a firm grip on even the tiniest irregularities. Some geckos also draw attention by making repeated loud calls. The name gecko comes from an onomatopoeic (a word sounding like the object it describes) sound. The arboreal tokay (Gecko gecko) reaches 35 cm. with a loud call, to-kay, to-kay, projecting to over 100 meters. Not all the species live in trees or in houses: many are terrestrial. All feed on insects and some of the larger ones gobble small lizards. Gecko eyelids are immobile, snake-like, a transparent cover of scales that is shed with the skin. It is kept clean with the lizard’s fleshy tongue. The body’s cover of minute scales feel velvety-smooth to the touch. As snakes and unlike most lizards, gecko eyes are covered with a transparent protector and the eyelids can not be moved. The eyelids are licked clean and shed at the same time as the skin. Geckos have no problems in re-growing a new tail, sometimes lost to get away from a predator. Geckos are both arboreal and terrestrial. Geckos feed on all sorts of insects, especially arthropods. The larger geckos eat small lizards. The arboreal geckos are good dispersers, having arrived early to New Guinea from the west. New Guinea has eight genera and 23 species of geckos. Five of the genera and three species are also found in Australia. Nothing special about the New Guinea geckos as they are related to those found elsewhere in the Indo-Pacific.
Information on gecko species is sadly lacking for New Guinea, except for some regional lists given in the second section of this book. From similarities with Australia, we are able to list some, but definitely not all the ones found on our island. The genus Crytodactylus, numerous and very wide spread but we only have the C. lousiadensis, in New Guinea. This is a spectacularly banded gecko with broad, purplish transverse bands. For the genus Gehrya, another speciose one covering the area from Madagascar to the bulk of the Indonesian archipelago, we have G. baliola, found in New Guinea as well as on the tip of the Cape York Peninsula. All members of this genus have great pads on their digits which are all with claws except for the inner ones. The genus Lepidocactylus is well represented in New Guinea, with a range running from East Asia to the islands of the Pacific Ocean. The genus Nactus has at least one member, N. pelagicus, in New Guinea with the species also found in the Pacific. The genus Pseudothecadactylus had two species identified way back in 1936, both large and with a semi-prehensile tail.
There are some 600 species of skinks, making this family the commonest in the world. They are also the most cosmopolitan, varying very much in body size, form and habits. The top of the head is almost always covered with large, symmetrical shield-like scales. Skinks show a snake-like trend to limb reduction and body-elongation, resulting from convergent evolution due to similar life-styles. Some species have no visible limbs. The skink tongue, used for eating and drinking, is flesh like in toads and frogs. These include the blue-tongued skink, Tiliqua scincoides. Skinks have large scales on the tops of their heads. Some lay eggs while others bear live young. Skink diet reflects size and hunting ability: the larger one are omnivorous, the smaller one stick to insects. Most skinks are active during the daytime hours but a fair number are nocturnal. Limbs are usually present, but now always. Reproduction varies from egg-laying to live-bearing.
Skinks are by far the largest family on New Guinea, as they are in Australia. They can be recognized easily enough by their shiny bodies and short legs, absent in a few species. Most species are active in daytime, with many other either crepuscular or nocturnal. Reproductive strategies are either eggs or live births. Most skinks live on a diet of insects but some are omnivorous. These lizards live in a wide variety of New Guinea’s eco-systems, ranging from the sea to above the tree line. The montane lizards, living above 1800 meters, fall into few species, but these are all endemic and wide-spread.
While there is some genus and species overlap with Australia, most stick to their own side of the Arafura Sea. Out of some 26 Australian genera, only 8 are also found in New Guinea. On the next level, the shared species are far fewer. These are Carlia Storri, Cryptoblepharus litoralis, Ctnotus spaldingi, Egernia frerei, Emoia atracoatata, E. longicauda, Eugongylus albofaciolatus, E. rufescens, Glaphyromorphus cracens, G. nigricaudis. The Tiliqua scincoides might be the same or a subspecies.
While there are few endemic genera, the skinks are the only family with many endemic species, showing extensive radiation on the island. The genus Emoia, with 43 widely distributed Indo-Pacific species, shows its greatest diversity in New Guinea with 20 species. Less wide-spread, the genus Eugongylus ranges from the Moluccas to New Guinea and on to Cape York and the Solomon Islands with three widely distributed species. Genera with a high proportion of endemic species are Lobulia (5), Prasinohaema (5) and Tribolonutus (8). In Irian, 87 of the 132 species of lizards identified so far are skinks, making up 66 per cent of the total. There are 14 genera in this western part of the island, with the numerically most important ones being Emoia (27 species out of a world total of 72) and Sphenomorphus (33 species).
The genus Carlia, with some 30 species, is the only Australian group to have spread extensively into tropical areas outside the continent: north and east Australia has 20 species, some of which are shared with New Guinea. The rest are endemic to the New Guinea-Moluccas area. All the lizards of this genus are small, terrestrial, diurnal and with well-developed limbs ending with four digits on the forelimbs and five on the backlimbs.
The genus Ctenotus attained only the south coast of New Guinea from Australia, with two species. Tiliquia, with 8 Aussie species, has but one species in New Guinea: the Tiliquia gigas, not found in Australia. This lizard extends west all the way to Sulawesi and Sumatra, its’ wide range explained by the fact that it is a live-bearer. It is irrationally feared everywhere as it is considered (erroneously) to be highly poisonous. Called ‘ular kaki empat” (four-legged snake) in Indonesian, many believe that there is no antidote for its venom.
The world-wide total of 300 agamid species, are found in the warm areas of Africa, Asia, Australia (species, mostly in the arid regions) and southern Europe. Many have a highly developed ability to change body coloration. Some have loose folds of skin along their sides, spread to glide between branches. Agamids in general are mostly terrestrial, with a few arboreal species. They are characterized by juxtaposed body scales, often with greatly enlarged tubercles and spines, long legs and tails, with many species sporting a remarkable erectable high crest along the back, more pronounced in territorial males. The body scales often feature large tubercles and spines, creating a fearsome appearance. Females usually bury their eggs. Agamids are active in the daylight hours, feeding mostly on insects, with the larger species preying on nesting birds, other reptiles and occasionally small mammals. The diet is rounded out with flowers and fruit. The analysis of the stomach contents of some New Guinea agamids showed the diet to consist of 70% arthropods (with grasshoppers making up almost 30%, beetles 12%, ants 10%), and fruits 30%.
Agamids show the most radiation in the drier parts of Australia. In New Guinea, agamids fall into six genera (with a total of 13 species in Irian), of which five are monospecific and none endemic. Chlamydosuarus kingi, Diporiphora bilineata (Two-lined Dragon), Lophognathus temporalis are found only on the south coast but area widespread in northern Australia. While agamids are quite diverse in south-east Asia, many are puzzlingly absent from New Guinea. This is especially true of the genus Draco, a gliding lizard, which reaches Timor but not New Guinea. All the genera, except for Hydrosaurus, are shared with Australia.
The genus Hypsilurus (formerly Gonocephalus) shows 30 species with distribution throughout Indonesia. At least eight endemic species (seven in Irian) call New Guinea their home. All are arboreal, living in both primary and secondary rain forest. Some reach 1.5 meters in length. They bear an uncanny resemblance to the New World tropics’ Iguana iguana. The members of this genus are a relatively recent migrant stock to New Guinea. They have heavy, angular heads, large and well exposed tympanum (ears) and tails at least twice as long as the head and body lengths combined. Only two species made it to Australia, neither of which is found in New Guinea.
The word for this family and its single species originates from the Latinized version of the Arabic word ‘waran’ which means to monitor. In Egypt, this word was applied to the Nile Monitor in the belief that this lizard warned humans of the presence of crocodiles. All 30 to 50-odd species of varanids are relatively large, ponderous, with strong fore and back limbs ending in thick, long and sharp claws. As snakes, south-east Asian monitors are forked-tongued which helps greatly with their most important sense of smell. Forked tongues are characteristic of the south-east Asian species. All varanids lay eggs. They are active only in daytime, after the sun warms them up.
The monitor lizards have advanced anatomical and physiological characteristics, bringing them closer to birds and mammals than any other group of reptiles. The are the most intelligent of all lizards, when tested in behavioral studies. They have had plenty of time to evolve, some 100 million years, since diverging from a parent group of marine lizards. While the varanids lack the variety of body forms characteristic of most other lizard families, they vary tremendously in size: by five orders of magnitude. Translated, this means that if the smallest monitor were to be mouse-sized, the largest would have the bulk of an elephant. This huge size variation is unmatched by any other terrestrial animal.
These lizards have prodigious appetites and stomach capacities which enable them to wolf down over three quarters of their body weight in a single meal. All are exclusively and omnivorously carnivorous, except for one which is partial to fruit. While other lizards tend to specialize in their diet, monitors are adaptable generalists, with cannibalism not excluded. Much of the smaller varanids concentrate on eating insects, with beetles providing the most calories per bug, but grasshoppers, moths and butterflies also sought.
Many cultures consider the monitor bite to be fatal and this is definitely true of some, not from any venom but due to bacterial infections. In both Australia and New Guinea, large lizards play prominent roles in the mythology. But this does not prevent the animals from being actively hunted both for their flesh and their skins. Tanned and dyed monitor skins are an important export item from Indonesia, much in demand for exclusive watch straps, purses and shoes. But there is little monitor skin exports from Irian. Some of the coastal groups use monitor skins as playing surface for their drums. Aside from reduced habitat from logging, humans are the greatest threat to monitors. In the eastern part of the island, the introduced cane toad, Bufo marinus, regularly eats small monitors.
Varanids include the largest lizard (over 200 kg on a very full stomach) in the world, Varanus komodoensis, as well as the longest (perhaps up to 3.5 to 4 meters), the New Guinea endemic, V. salvadorii, the Papuan Monitor.
World-wide, there are some 45 species of monitor lizards, but with many taxonomic revisions on the way, especially concerning the ones New Guinea. Current subspecies could become ‘new’ species and some current species could be lumped together. Collecting varanids in New Guinea is no easy task, while trying to observe them in the wild is even tougher.
According current research and taxonomy, there are eight monitor species on the mainland of New Guinea, with several more found only on nearby islands. Out of these, three are endemic, with a possible fourth.
The large varanids found in New Guinea come from the west, the south or are endemic. The Australian species, Varanus gouldii and V. scalaris, are recent arrivals and restricted to the island’s south coast. (All Australian varanids are called ‘goanas’, a corruption of the world iguana, a New World lizard.) From the west, we have the V. indicus a very wide-spread, semi-aquatic species. Endemic species include the V. jobiensis (alias V. karlschmidti), V. salvadorii, V, doreanus and V. prasinus. [some sources suggest as many as seven endemic varanids here]
The very aquatic varanid, V.
salvator (not to be confused with the longest lizard of them all, the V.
salvadorii) does not reach New Guinea from the west. Instead, we have the
While the V. salvator provides one million skins for export from Indonesia on a yearly basis, our V. indicus is mostly eaten by local Papuans also who use its nicely patterned skin as the playing surface of their drums. For some unknown but highly appreciated reason, the Mangrove Monitor’s skin does not figure in the international trade. While the V. salvator will eat anything, even the pest toad Bufo marinus, which poisons any other animal trying to swallow it, our V. indicus has been seen, quite dead, with this toad in its mouth. The Mangrove Monitor has a large range, from Lombok to the Solomons, including northern Australia. Its many subspecies very greatly in size, body pattern and scalation.
Arguments as to the length of the V. salvadorii have not been resolved. Anecdotal figures run as high as five meters, but no controlled measurement comes close to this. The longest confirmed figure does not reach three meters. Two-thirds of body length comes from an extremely long tail, which is usually kept curled up and used for defense. One of the leading authors on varanids, Daniel Bennett, suggests that the longer body might belong to a species as yet unknown to science as he feels that there are probably many undescribed monitors in New Guinea. Be that as it may, he calls this monitor ‘one of the world’s greatest ecological enigmas’. About all we know is that it lives in trees. The range of the animal is also known: the south coast of New Guinea, up to but not including the Bird’s Head. One of this lizard’s common name, Crocodile Monitor, is based on its great size, along with a large, bulbous nose and particularly long teeth.
The Emerald or Green Monitor, V. prasinus, has several subspecies, All range in color from an intense green to black (or, with a black band pattern on the back), depending on the rainforest surroundings. It is well adapted to its arboreal existence, with the tail used an additional very dexterous limb as well as for defense. The soles of the feet show enlarged scales to facilitate climbing. This New Guinea endemic is almost as much of an ecological mystery as the V. salvadorii. It is only known that it eats insects and spiders and live in the rainforest, palm forests, mangroves and cocoa plantations.
The Varanus jobiensis, commonly called the Peach-throated Monitor, also goes by the scientific name of V. karlschmidti. It looks like the V. indicus but has smaller scales, especially on its neck and the sides of the head. Its tongue is a bright red with a black or light-colored tip, while the V. indicus has a black tongue. The common name comes from throat which turns to a lighter color when the is bothered. It grows to about 120 cm. and often shows dark bands across the back.
The Varanus doreanus also resembles the V. indicus but it is smaller, with more numerous scales on the back, a bright underside a white tongue and a striped tail. The tail’s color is the reason for the common name: Blue-tailed Monitor. It is widely distributed in New Guinea. The holotype for the original name by Meyer in 1874 was lost to a World War II bomb, but the original very precise description led to its ‘rediscovery’ in 1994.
Varanus gouldii, alias V. panoptes, needs to have its taxonomy sorted out. It is poorly known, even if it lives in north and west Australia, along with the grasslands of southern New Guinea. The animal is usually found in dry country and often stands on its hind legs for a good look around. The common name is Gould’s Goanna and there are three accepted subspecies. While there are lots of variation in color, pattern and size, the one common feature seems to be a well-defined temporal stripe. The last few centimeters of the tail are of a very light, contrasting color. The nostrils are lateral (on the sides) and located much nearer to the tip of the snout than the eyes.
Taxonomic problems come to the fore again with the last New Guinea species, currently going under the name of Varanus scalaris, the Banded Tree Goanna. It was originally described as a subspecies of V. timorensis, then became V. similis before settling to its current name. But as there is great variation in color and pattern, the animal could turn out to be a complex of several species. As its name implies, this monitor is arboreal and has been observed hunting large insects. It also eats other lizards, sometimes its own size which reaches 60 cm. The varanid is found mostly in northern Australia, with a small patch of habitat in the dry area around Merauke and the Fly River Delta.
Snakes are distinguished from lizards by two very obvious physical characteristics: they have no legs and their ligament-connected jaws are made so that they can move apart to swallow prey several times larger in diameter than themselves. But even the limbless state of snakes has to be qualified in that some ‘primitive’ snakes, such as pythons and boas, have vestigial hind legs. And within the lizard grouping, we have the a family called Pygopodidae, the snake-lizards, whose forelimbs are completely absent. For crawling, snakes rely on smooth, overlapping scales, with a series of transverse, enlarged plates on the stomach. While most lizards have moveable eyelids, snakes eyelids are fused into a transparent membrane. Combined with a lack of eyeball mobility, this leads to the snakes’ stare, considered to be ‘hypnotizing’ by some people. Snakes lack the appendages found in some lizards: spines, tubercles, horns and crests. Most snakes have an excellent sense of smell thanks to their forked tongue connected to pits called Jacobson’s organs located at the roof of the mouth and with direct connections to the brain.
The world’s snakes (about 2600 species at the last count) are divided up into 13 families, with the island of New Guinea hosting members of seven (or eight) of these families. Compared to frogs and lizards, the island is poor in snake fauna. All but one are also found in Australia. The well-documented PNG side of the island lays claim to 98 species (terrestrial, freshwater and marine) with a further dozen to be added from the Irian side of the border. The total for the western half of the island is 78 species, but there are very likely other species out there, waiting to be found and counted. Of New Guinea’ eight snake families, only the boas of the Boidae, wide-spread elsewhere, did not reach Australia. At least that is the case in a recent re-classifications where boas as separated from pythons. Formerly, pythons and boas were lumped together into the same family, Boidae. Now, only boas made up the eponymous family, Boidae, but many reference books still follow the older system. Here, Pythonidae do not qualify as a separate family.
There is a secretive burrowing snake, family Typhlophidae, commonly called blind-snakes, which are found around the world in the tropics. Very little is known about them (due to their secretive life-style), except that they are shiny-scaled, oviparous, with hardly any eyes and a small jaw with only upper teeth. Non-poisonous, they can emit a strong, stinking odor from well-developed anal glands. Their diet is almost exclusively soft-bodied invertebrates, mostly termites and ants. There are three genera and at least 10 species on the island, with six in Irian.
The true seasnakes are grouped in the Hydrophiidae family, with 12 genera and some 21 species found around the island’s coastline. Their main adaptation to a watery habitat are a paddle-shaped tail for swimming and a capacity to draw some oxygen from the water while passing out carbon dioxide. This latter feat enables them to spend up to two hours underwater and dive to 100 meters. Due to their marine habitat, many are wide-spread, with some species ranging from Persian Gulf to the Pacific. A few are restricted to the Arafura Sea and nearby. Most of the species are viviparous, giving birth at sea. These snakes are close relatives of the Elapidae family, nasty customers.
The true sea snakes are related to the Elapidae family which also has some marine species. These include two species of banded sea kraits of the Laticauda genus. They are marine snakes, poisonous and viviparous, with paddle-like tails. Unlike the true sea snakes however, these kraits handle themselves quite well on land and, also unlike true sea snakes, lay their eggs on land. They are highly poisonous but reluctant to bite humans as they have a very small mouth. They come on to land to lay their eggs. Due to their marine habitat, the sea snakes are not found as endemics in New Guinea. In Irian, there is but one genus, Laticauda, with two species: L. colubrina and L. laticauda.
All the other species are terrestrial. Members of the two families have short, fixed fangs at the front of the upper jaw. The terrestrial elapids are generally called front groove-fanged venomous land snakes. They include such nasty customers are cobras, kraits, taipans, coral snakes and mambas. These are the most dangerous venomous snakes in the world. The family is the most diverse one in the Asian-Australian region, forming the dominant element of the Australian snake group.
Australia’s Elapidae family, of Asian origins, is the dominant element of the snake fauna. In New Guinea, the family members include four genera of mildly venomous snakes and three genera of highly poisonous ones. Three genera are endemic to the island. Irian has seven genera with a total of 11 species. Among the latter, we find the genus Acanthophis, New Guinea Death Adders in ecological niches occupied elsewhere by vipers which are absent from the entire region. The genus is characterized by a broad, somewhat triangular head, short and stout body with a thin, rat-like tail ending in a soft, curved spine. This tail tip is twitched to attract prey, luring it to within striking distance. The snakes of this genus are usually nocturnal and secretive, with cryptic coloration to escape detection by large varanids and the biggest birds of prey. They spend the daylight hours under brush or shrubs or at the base of a tree. Their large fangs inject very toxic venom, making them among the most dangerous snakes in the world. We know of several Papuans living in south coast villages which have been killed by one of the members of this genus, Acanthophis antarcticus, the Common Death Adder.
There is worse in the elapid family: one the planet’s nastiest of customers, the Oxyuruanus scutellatus, the Papuan Taipan. This beast, reaching over three meters in length and with a hefty body to match, has acute senses and tries to avoid humans. But if there is a close encounter, the taipan delivers a series of rapid strikes, injecting an enormous dose of venom. This snake will pursue a fleeing prey or even a human, adding to its nasty, aggressive reputation. Fortunately, it only lives in the south-east corner of Irian but are more wide-spread in PNG. Dr. Carelton Gajdusek, a Nobel prize winner, told me of one of this porters who cut off his own hand after being stung by a taipan, knowing he would quickly die otherwise. Fortunately, Dr. Gajdusek was close by and could staunch the flow of blood, saving the man’s life. With good reason these taipans, along with their Australian relatives, are considered to be the most venomous land snakes in the world. All the elapids inject their venom through their hollow front fangs connected to sacs containing a strong neurotoxin.
Pythons and boas make up the Boidae family, the largest living snakes. There is a relative plethora of pythons in New Guinea with 8 species, beaten only by Australia’s 15 and Indonesia’s 13, on much larger land areas. All of Africa has only four species and for the Asian mainland it’s down to two. Pythons are blessed with heat-sensitive, thermoreceptor pits on their lips to sense the heat given off by mammals even on dark, moonless, spooky nights when they do their hunting. Boas and pythons also feed on birds and some other reptiles. The pythons lay clutches of leathery eggs incubated within the female’s coils.
There is some confusion as to the scientific names of some of the genera of pythons between the names Chondropython, Morelia, Leiopython and Liasis. We have followed the most recent reference book at our disposal (O’Shea) but not all snake experts agree with the designations used below. Older text show the genus Chondropython as monotypic. Since 1993 it has been folded within the genus Morelia. Whatever the name, these are nocturnal and arboreal snakes, reaching 2 meters (but usually a more manageable 1.2 meters). The genus Morelia is characterized by its head which is covered by small, irregular broken shield-scales or large symmetrical ones. All the members of this genus are found only in New Guinea and Australia.
The New Guinea pythons are both arboreal and terrestrial. Some are stunningly beautiful, such as the Green Tree Python, Morelia (ex-Chondrophython) viridis whose juvenile bright yellow body coloration metamorphoses in six to eight months to an emerald green in adults while keeping intricate patterns. Other pythons include the wide-spread Morelia amethisiana, commonly named the Amethystine Python for its coloration. It is iridescent olive-yellow or olive brown on its back. The rest of the body shows many irregular, broken dark brown or black transverse bands, connected on the lower sides to one or more longitudinal lower stripes. The animal can reach a hefty eight meters. It lives in a wide variety of habitats, ranging from rain forest to open savanna to monsoon forest, regrowth and scrub vegetation.
There are also two rare, endemic pythons. The iridescent D’Albertis or White-lipped Python, Leiopython (ex-Liasis) albertsii, restricted to the monsoon forests, secondary regrowth and wet southern lowlands and coastal plain of south-central of New Guinea and the Torres Strait. Even rarer, Morelia (ex-Liasis) boenleni, Boelen’s Python, is found only in scattered highland habitats of Irian Jaya. Two more species round out the python population of six in Irian: the Apodora caninata and Liasis fuscus, the Brown Water Python found around Merauke.
Boas are differently from pythons in that they bear live young and have some skull differences. Most boas are found in the Americas. The three boas of New Guinea, all of the genus Candoia, are closely related to the Caribbean species, having probably rafted across the Pacific and between the American prior to the joining of the continents. O’Shea writes that the ‘Pacific boas are and extremely diverse group containing both stout-bodied, short-tailed terrestrial specimens and slender, long-bodied arboreal specimens, even within the same species.’. New Guinea boas include the Candoia carinata, the Pacific Boa found on the island as well as the Moluccas and the Solomon Islands, and the C. aspera, the New Guinea Ground Boa, living only on the island and some of its offshore islands. This single genus is endemic to the Indo-Pacific region. Only two species are found on the island. Boas are absent from Australia.
The filesnakes of the Acrochoridae family have none of the beauty (to some) of the pythons. The filesnakes’ alternate common name, wart snakes, describes them well: rough, baggy skin. The family is a small one and has only recently been grouped into this separate taxon. These snakes are fully aquatic as the lack of stomach plates prevents efficient crawling. The habitat ranges from fresh water to marine. They feed exclusively on fish. One genus with two species are found in Irian: Tropidonophis and Dendrelaphis.
Another species, Arochordus granulatus, the Little File Snake, found in PNG also ranges throughout Indonesia to Australia.
The 2000 plus species of colubrid snakes (Family Colubridae) make up some two thirds of the world’s total number of snakes. These snakes are dominant in all parts of the world, except for Australia. They are quite similar to vipers, with coloration as the most obvious distinguishing feature. But for positive identification, a closer look is needed: colubrid snakes have only three large scales between the eyes. Vipers are not found in New Guinea and colubrids are poorly represented. There are 13 species of keelbacks, and six species of non-venomous tree snakes. The subfamily Hamalopsinae is characterized by mildly poisonous rear fangs, used to paralyze the prey before swallowing. In New Guinea we have six species of these rear-fanged snakes living in the mangroves or other muddy, watery habitats. The largest genus on the island, Tropidonophis, holds 13 species here. Other genera include Dendralaphis, slender and agile tree snakes; the mildly venomous Endydris, the Fordonia which has but one species, the F. leucobalia, the White-bellied Mangrove Snake, the genus Stegonotus, dark colored, with both terrestrial and arboreal habits. The totals for Irian colubrids are 11 genera and 29 species.
World wide, there are some 270 species in this order. Common names vary from country to country. The most usual terms are tortoises those of the land habitat and turtles for marine species. The word ‘terrapin’ can be used for those at home in fresh water and land. In the USA, all are called turtles, although strictly terrestrial ones should be called tortoises. In the USA terrapin was a term used by early settlers for a variety of edible saltwater and brackish water chelonians. The turtle population had 24 families, half of which are not extinct, half still living. The turtles’ upper shell is called a carapace and the lower shell the plastron. Both form polygonal dermal plates, similar in composition to birds’ beaks. The body armor has evolved from modified vertebral and rib bones. For some species, reaching 150 years of age is not exceptional.
Turtles in New Guinea are represented by five families. The Family Cheloniidae group most of the marine turtles, the Chelidae are aquatic or semi-aquatic (these are called tortoises in Australia), the Trionychidae are the long-necked turtles and the Family Carettochelydae, monotypic with but a single species. The leatherback marine turtle belongs to the Family Dermochelydae. New Guinea turtles include six marine species and seven living mostly in fresh water. In Irian Jaya there are three families of non-marine turtles. New revisions have added some species to the list. The Trionychidae family has now two species, Pelochelys cantorii endemic to the south coast, the other, Pelochelys bibroni in the north of the island and found all the way to China. In the Chelidae family, there are now six species in Irian, with the earlier Elseya novaeguinea having split off a southern species, E. siderbrocki. Irian’s current non-marine count is now eight species, grouped into five genera in three families.
Family Dermochelydae. The huge leatherback, Dermochelys coriacea, is the only species in a family of its own: Dermochelydae. It differs from the other turtles in the thinness of its carapace which is not fused to the underlying skeleton but has a heavy skin covering with a leathery appearance, the basis of the turtle’s common name. The carapace is somewhat heart-shaped, made up of dermal bones. It is not fused to the vertebrae or ribs but made up of small, polygonal dermal bones, called osteoderms, which form a sort of embedded mozaic in the skin. Some enlarged osteoderms form a very visible feature of the leatherbacks, showing a series of several rows or high keels running from head to tail, along both the plastron and the carapace. The heavy, paddle-shaped limbs show no ankle joints or webbed, clawed feet. These turtles can reach close to two meters in length and weigh some 400 kg. There is an important nesting place for these turtles on the north coast of the Bird’s Head, at Jamursba Medi, now a nesting beach reserve. The species wanders the furthest from the tropics, into the higher latitudes of the temperate sea zones to pursue its meals of jellyfishes. These include the long, dreaded stinging Portuguese Man ‘War, Physalia utriculus.
Family Cheloniidae. These are all marine turtles, with all limbs modified into efficient swimming flippers but without webbed or clawed feet. All but one of the large sea turtles, the leatherback, are included in this family. It is likely that all the species visit New Guinea waters. The two most frequently encountered species are the hawksbill, Eretmochelys imbricata and the green, Chelonia mydas. The former has been over-hunted for the fine, overlapping scutes on its carapace, the material of ‘tortoise-shell’ commerce. The common name comes from the distinctively hooked, parrot-like upper jaws, used to crush its diet of shelled marine animals. The edges of its carapace shows distinct serrations, similar but somewhat less pronounced in the green turtle. The two species can be distinguished by the fact that the green has two prefrontal scales on the top of its head while the hawksbill shows a pair of these. While the green turtle’s shell is not so valuable, it is also over-hunted, mostly to furnish the thriving (and mostly illegal) turtle consumption on Bali. The Lepidochelys olivacea shows six or more costal shields on each side while the hawksbill has only four. The Natator depressus is endemic to the Australasian region. The members of this family breed only in the tropics and most lay several clutches per season. However, every third year or so, no eggs are laid.
Family Chelidae: these aquatic or semi-aquatic turtles are mostly found in Australia, with a very few species in New Guinea and South America. The limbs are not paddle-shaped but jointed and tipped by four or five claws. These turtles are pleurodirous, meaning that the head and neck can be tucked under the front edge of the carapace thanks to one or more horizontal skin folds. Both the front and back limbs are jointed, not shaped like paddles, with quite distinct ankle-joints. The feet are webbed with four or five claws. The New Guinea Snapping Turtle is an endemic but very wide-spread, especially in rivers and swamps along the coast. The family has five species on the island, with four found only in the south, mostly in still waters. Elseya novaeguineae and Chelodina siebenrocki are endemic to New Guinea, and Chelodina parkeri endemic to the Fly River basin and coastal areas. The more wide-spread Chelodina novaeguinea carries a markedly convex carapace, oval in shape. The coloration runs to a spotted brown-black on the carapace, with the plastron being white. The animal lives in swamps, oxbow lakes and billagongs, an Australian term meaning slow-moving river.
The genus Chelodina sport exceptionally long necks, whence their common names of Long or Snake-necked Turtles. Hunters attest to a foul-smelling, viscous liquid secreted when the animals feels danger. This is produced by musk glands. The species is carnivorous, living on a diet of fish, mollusks and crustaceans. The genus is characterized by five claws, along with a gular shields which meet in front of the intergular. The carapace, with no upturned edges, takes forms varying between subcircular to heart-shaped. There are four costal shields. Other identifying features are an absence of a hooked beak and a series of enlarged scales on the upper eyelid.
The other genera of this family, Emydura and Elseya, also have front limbs tipped with five claws but the gular shield is clearly separated from the intergular. In addition, the sutures connecting the costals are distinct from the Chelodina and the neck is shorter in
the Emydura. All the Emydura species have smooth skin at the temporal area, sometimes broken up into regular, flat scales or tubercles. The nuchal shield is usually present, not the case with the genus Elseya, although the two genera are closely related. This Elseya’s temporal region is covered with distinctive skin, featuring prominent, low, rounded scales or tubercles, raised on the head surface. The genus can also (sometimes) be differentiated from Emydura by a horny head casque. The members of the Elseya genus are omnivorous, feeding on pandanus, various fruits, mollusks, crustaceans and fish.
Emydura subglobosa can easily be identified by a bright yellow stripe running from the corner of the mouth to the ear, with, often, another similar stripe along the upper jaw. Their limbs are sometimes spotted bright red with the plastron and lower edge of the shields usually showing distinct red blotches.
Family Trionychidae. The turtles of this family have soft and leathery shells, fully webbed feet and an exceptionally long neck tipped by a tubular snout. They often bury themselves in mud or soft substrates with only the head poking about to catch unsuspecting passing fishes, crustaceans or frogs. They are active at night. The animals are bad tempered, having bitten many a finger. The Asian Giant Softshell Turtle, Pelochely bibroni, has wide distribution and found from India and China as far east as New Guinea. This has resulted from its adaptability: the range of habitats include fresh water streams and deep waters far inland to the estuarine and even the sea. The animals is also close to omnivorous, feeding on fish, crabs, mollusks and even aquatic plants. The flat, rounded adult shell can reach well over a meter.
Family Carettochelydidae. The Pig-nosed Turtle (also: Pitted-shell Turtle), Carettochelys insulpta, the sole surviving member of this family was long thought to be a south-central New Guinea endemic. But in the 1970s some were found in north Australia. The turtle is closely related to the soft-shelled turtles of the Family Trionychidae, wide-spread and found in Africa, Asia and North America. But the pig-nosed differs in having no dermal (skin) scutes (eternal bony or horny plates) in the shell. Instead, soft, pitted skin covers the carapace. The paddle-shaped fore-limbs, like those of sea turtles, are tipped by two claws. The common name comes from the very prominent, fleshy proboscis holding the nostrils.
The word crocodile come from the ancient Greek word for lizard, while the more general scientific term souchian, as in Archosuchians (archo, a prefix meaning old) comes from a Greek distortion of Sobek, the Egyptian crocodile deity. Sobek was adored as a manifestation of the sun-god Ra with the town of Crocodilopolis as its center of worship.
Crocodiles are the last survivors from the dominant fauna of the Age of Reptiles, descendants of the thecodontians (referring to tooth arrangement, see below) in an evolutionary span that has lasted 200 million years. Their ancestors were part of a group called Archosauria which included the pterosaurs (flying reptiles) and the dinosaurs as well as the thecodontians. Crocodile ancestors included tiny meter-long fellows along with one of the most fearsome animals invented by nature, an 11 meter, six ton killing machine named Deinosuchus, meaning ‘the terror crocodile’. Today’s crocodiles are the only living representatives of the most successful group of land-dwelling vertebrates ever known, the Archosauria or ruling reptiles which dominated animal communities from 245 to 65 million years ago. One obvious shared feature between archosaurs is the difference in the length between the fore and hind limbs.
Other, less obvious shared features with a section of one of the groups of Archosaurs include the teeth attachment and position. The Archosaur group called thecodonts take their name from the way their teeth are attached in the jaw as well as the position their teeth which are set in sockets rather than fused to the top of the jaw. This is different from other reptiles which are acrodonts (teeth fused to the top of the jaw) or fused to the side of the jaw, as with the pleurodonts.
Archosaurs and contemporary crocodiles also have diapsid (two-arched) skulls. This means that the temporal (side) area of the skull has two opening, allowing for the expansion of the jaw muscles. Two large openings, called temporal fenestra are found behind each eye socket in the cheek region, outlined by bony arches. This diapsid feature distinguishes them from humans, with only one opening (synapsid) for the expansion of the jaw muscles and the turtles with a solid cheek region without openings (anapsid). Two openings are better than one in allowing large and strong muscles which needs to expand when contracting in powerful bites. Needless to say, powerful jaws and large teeth combine to make them fearsome predators, with no natural enemies except for parasites and man.
There have been two crucial features in the physical development of crocodiles. While the basic body plan has remained the same over 200 million years (as with sharks and turtles), these improvements were essential to successful survival. The ability of crocodiles to allow the mouth to remain open underwater while still breathing was make possible by the gradual enclosure of the secondary bony plate in the mouth, with the back of the tongue keeping the water out as well. Like mammals, crocodiles have this well-developed secondary plate, made up the maxillary, palatine and pteroid bones meeting at the roof of the mouth. The nasal passages are above this secondary plate, in the back of the throat and in back of the fleshy fold of the tongue which separates water from the inhaled air. The second adaptation, the gradual evolution of ball and socket (proceolous) joints liking the vertebrae has increased both the strength and the flexibility of the spine. Furthermore, the back is covered with bony plates which are neither fused nor joined to the skeleton, allowing surprising speed in these bulky creatures.
These and other helpful evolutionary features, in place by 80 million years ago, came in the nick of time. A mere 15 million years later, a great extinction wiped out the dinosaurs and many other groups of animals. This marked the end of the Mesozoic Era and the Cretaceous Period while signaling the beginning of the Cenozoic Era, the Tertiary Period and the Paleocene Epoch, A landmark on the history of the earth, the equivalent of the beginnings of multicellular life. The survival of crocodiles at this time allows for some clues as to the background for this period so disastrous to animal life. Living crocodiles can’t survive in the cold, so there could not have been a major climatic deterioration. Crocodiles made it through, even at high latitudes. Freshwater vertebrates (including fishes, amphibians, turtles as well as crocodiles) survived the crisis much better than terrestrial or marine communities, probably due to the negligible effect on the food chain in that ecosystem.
The contemporary crocodile family is the most advanced one among the reptiles today: tough survivors with many features evolved millions years ago and still useful and deadly efficient today. Most of the advanced features are internal (such as the heart, diaphragm, the cerebral cortex) while their primitive external morphology has changed very little and reflects their primarily water habitat. Thus with just the low-lying snout of the water, crocodiles can breathe while staying almost completely submerged and concealed from prey and foe.
A four-chambered heart allows for excellent blood circulation and spongy lungs are best for the essential oxygen-carbon dioxide gas exchange. Unlike other living reptilians, a four-chambered heart enhances efficiency of blood circulation by separating oxygenated from non-oxygenated blood. During a dive, the brain and the heart continue to receive the good, oxygenated air while deoxygenated blood goes to less vital organs, such the as stomach, liver and intestines. Another mammalian counterpart, the diaphragm makes for more efficient lung ventilation.
Crocodile skin forms a thick dermal layer covered with non-overlapping ossified (bony) epidermal (skin) scales called scutes. Osteoderms (bony buttons or plates (literally meaning bony skins) are embedded in the skin to form a protective dorsal armor. The first few rows scutes of this dorsal armor, those just in back of skull, are reduced in size or completely deleted to allow the flexibility needed to toss the head back to get mouth out of water when swallowing prey. The most modern reduction of scutes in the nape and neck, are seen in the American and Indopacific crocodiles, the two salt-tolerant ones with oceanic distributions.
While crocodile skin is a marvelous blend of protection and flexibility, its thickness presents some problems for the owner. Heat exchange takes longer, as compared with thin-skinned animals such as frogs. Crocodiles are poikilothermic, needing solar radiation and the conduction of water to regulate their body temperatures. However, large crocodiles are only slightly influenced by ambient air temperatures. The Indopacific Crocodile, Crocodylus porosus, surface in the water early morning briefly, then submerge for most of the day. To aid in cooling, they move to land at night. When cold, crocodiles submerge and survive with only their nostrils out, even if surface freezes. Core temperatures can drop as low as 5º C, with full recovery later. Large crocodiles survive by capitalizing on the thermal inertia inherent in their large body masses. The crocodiles’ thick skin prevents the loss of fluids, thus the kidneys concentrate nitrogenous wastes into uric acid.
Some crocodiles have kept an ancestral feature developed before there was much fresh water on earth. Crocodiles and other reptiles are cursed with inefficient kidneys, incapable of excreting much salt without freshwater to flush it through their systems. Crocodiles, turtles, sea snakes and other marine reptiles are equipped with salt glands that can excrete very concentrated salt solutions with minimum water loss. Too much salt in the blood is not tolerated, so excess must be released through salt-extrusion mechanism. Mangrove plants have developed this, as did ancient crocodiles. Today, while no crocodile is marine (living almost exclusively in the sea), there are estuarine specialists, living in tidal areas with waters too high in salt for their own good. Thus, for example, the Indopacific crocodile has special salt glands on its tongue to excrete excess salt. Ability to tolerate salt water is related to their thick skins and low rate of water loss (as compared to the rate of other aquatic reptiles) and low rate of sodium uptake. Other mechanisms include the ability to excrete excess sodium and ability to osmoregulate (regulate the composition of body fluids by osmosis) behaviorally by not drinking salt water after feeding in saline areas. The large amounts of energy needed to catch food and excrete salt have prevented other crocodiles from competing successfully with the Indopacific species in saltwater habitat.
In summary, crocodile anatomy is an intriguing combination of reptilian and mammalian or avian characteristics. Among living vertebrates, crocodiles are most closely related to birds rather than lizards: both birds and crocodiles are blessed with elongate outer-ear canal, a muscular gizzard, and complete separation of the ventricles of the heart. Both build nests and show a degree of parental care. Crocodiles also own a complex bird-like brain, an advanced hard upper mouth palate, a four-chambered heart, an efficient respiratory system but no bladder and a relatively unmodified digestive system. The fact that the body structure has changed relatively little in the past 200 million years attests to the success of the basic design.
Crocodile behavior and environment
All of the various species of crocodiles are superbly adapted to their watery environment, swimming with back-and-forth undulations of their powerful tails. The feet are usually folded alongside the body, but show greater ancestral use in water by the five front toes and the four back ones connected by webbing. But if the feet are not much used in the water, they are quite efficient on land. With no pressing matters at hand, crocodiles move on land by scuttling forward on their bellies. When urgent matters require speed, the legs are brought almost completely under the body, thus raising it, as with fast, efficient mammals. When conditions become matters of emergency, crocodiles can gallop in short bursts of up to 17 kilometers an hour, speedier than most humans. (Top athletes run the 100-meter dash in the equivalent of about 30 kilometers an hour.)
Crocodiles kill their prey by a combination of a slow, stealthy stalk followed by a quick, ferocious, crippling charge. Even large crocodiles are capable of vaulting almost vertically out of water as high as 1.5 meters to snap at birds or animals on riverbanks above them. Their enlarged canine teeth with cutting edges are well adapted for seizing, puncturing and gripping prey, but not good at all for chewing. (Tooth replacement takes place is ‘waves’ with alternate, neighboring rows of teeth replaced at the same time.) Huge bites are swallowed whole by throwing the head back and letting the chunk slide down the throat. The a two-part digestive system takes over. First, a bird-like muscular gizzard grinds up the food, followed by a bath in gastric juices strong enough to dissolve bone. While crocodiles will attack an kill must about any animal (except for adult elephants and hippopotamus), their elongated snout attest to fish as their evolutionary staple. All but the largest fish are also easy to swallow, once it has been maneuvered into to head first position. Problems arise when dealing with a freshly-killed, thick-skinned animal. Just about all kills are made in the water. Once the animal is dead, the crocodile tries to grab a limb and twist it off by spinning in the water. But generally the noise of the prey’s struggles alert other crocodiles that there’s a meal handy and social, cooperative feeding takes place. Some hold, others rip, taking turns. This is quite similar to the cooperative feeding sometimes seen with Komodo dragons, the largest surviving lizard. It is an erroneous belief that crocodiles prefer rotting meat and hide their large kills until putrescent and easy to tear apart.
While voracious eaters, adult crocodiles probably eat no more than 50 full means a year. A one ton crocodile can probably last two years without food. This is due to their super-efficient metabolism. They extract more from their food than most other animals. This is due to the thoroughness of digestion. Their stomachs are the most acidic of any vertebrate, digesting bones, horns, hoofs and everything in between. Some 60 per cent of the energy from food stored as fat in tail and elsewhere. And crocodiles do not need to expand lots of energy to maintain body temperature at a constant level as they are ‘cold-blooded’. When needed, there is lots of energy available but only for a little while and with a very high level of lactic acid build-up. The levels of lactic acid tolerated by crocodiles astonish researchers with levels that would kill most other animals. However, this means that they become easily exhausted and take long time to recover from exercise of any kind.
Crocodiles have good hearing, an excellent sense of smell and keen eyesight, especially at night when their can see with the visual acuity of an owl. This is thanks to a reflective layer (the tapetum lucidum) lying behind retina. These cells contain guanine crystals which form a mirror-like layer reflecting most of the incoming light back through the light-receptor cells, produces the characteristic yellow-orange-red eyeshine familiar to nighttime crocodile observers and hunters.
After their first year of life, on reaching about one meter in length, crocodiles have little to fear except from larger adult males and humans. They are the masters of their universe. However, the mortality rate during the first year of life reaches about 90 per cent.
Unlike most birds with relatively small clutches of eggs, but two or three broods in each breeding season, crocodiles lay large number of eggs but only once a year: 20 to 80 for most species. Incubation takes longer than with birds, 35 days for smaller species, 90 to 100 for larger ones. Lots can spoil the eggs: dryness, heavy rainfall (oxygen needs to diffuse through porous eggshells); turtles laying their own eggs in crocodile nests can damage existing ones; mammals and birds eat crocodile eggs. But the greatest predator of crocodile eggs are the various species of monitor lizards. Birth defects can happen if fish is the predominant diet of the mother as fish is deficient in fat-soluble vitamins as E and trace minerals like selenium. Juvenile crocodiles have plenty of predators as well, starting with their own species, and including birds, lizards and humans.
All members of the crocodile family are oviparous, laying eggs near water in nests of vegetation whose heat of decomposition encourages the hatching process. Many crocodiles in northern New Guinea make nest on mats of floating grass which are effected by flooding or over-heating. Unlike birds and mammals, the sex of the crocodile embryo is not determined at moment of fertilization but the nest temperature during in first few weeks of incubation as with many turtles and some lizards. In all species, much more females hatch at lower temperatures as well as higher ones. Males thrive at intermediate temperatures. For every species, one half to one degree Centigrade can make all the difference in the sex ratio. In many crocodile nests, all siblings are the same sex, in wild skewered for females.
Crocodile behavior is surprisingly complex and sophisticated. Communications start before birth among the embryo still inside the eggs, helping to synchronize the hatching.
These animals can make a variety of sound with air pushed through, continuously or in pulses, the larynx. Sounds range from very low volume, barely audible coughs and hisses, to high volume roars and bellows. Juvenile distress call alerts its peers of impeding danger and may prompt adult attack. Social feeding can be common and crocodiles often tolerate the presence of smaller individuals of the same species, by for the large breeding males in the rutting season. For example, the Indopacific Crocodile defends its territory year-round, although this territory may vary in size with seasonal changes of habitat and seasonal reproduction. Adult males fight in various ways, including head ramming. This is a particularly brutal display of strength: with bodies parallel, facing in the same direction, heads are swung to one side for momentum then are bashed with loud thud. This can go on for an hour but there is little permanent damage, with the loser slinking off, only slightly worse for the wear, when he has had enough.
The two greatest threats to today’s crocodile populations come from environmental restriction and degradation, along with illegal hunting. With ever-increasing forest clearing to cut timber and for human settlements, there is a price to pay in soil erosion. This results in the soil’s inability to hold nutrients, resulting in nitrates and phosphates being washed away into lakes and streams where then algae multiply ad infinitum. With algal blooms, oxygen levels drop, decreasing the survival chances of all species of aquatic like, including fishes and crocodiles.
Any ecosystem has its keystone species and crocodiles are the ones for many riverine and estuarine communities. The keystone species determine the structure of a community and if the keystone species dies out, a drop in species diversity is the usual result. Food chain is dependent on a major predator as the source of nutrients for primary production in this electrolyte-poor habitat. The greater and more varied the animal life, the more stable the community seems to be. Local fishermen in many areas prefer to fish where the crocodiles live, perhaps because their nutrient recycling is of benefit to the whole system.
Crocodiles and humans
Worshipped and defiled, the crocodiles’ relations with humans covers a wide range. The high point for crocodiles was in ancient Egypt where they were worshipped under the name Sobek, centered in a city named after them, Crocodilopolis. While in Egypt the crocodile was associated with wisdom, in Europe the emphasis shifted to their savagery and treachery. In China, the crocodile had its own written character well over a millenia before Christ, and there too it was considered evil and violent, aside from unlucky. It might also have served as the model for their cosmic dragon. In parts of black Africa, the crocodile was worshipped as the recipient of ancestral spirits while in south-east Asia as the reincarnation of the departed ruler. There are references of the Princes of Kupang, in West Timor, making offering of beautiful maidens to serve as wives to their ancestors. In Kalimantan, crocodiles could become someone’s powerful blood relation, driving evil away. Rock art in Australia shows crocodiles going back 30,000 years, including a famous one showing one giving birth to a human in Dreamtime, when all things were created. In Cape York Peninsula, only certain elders were allowed to eat crocodile eggs, and ancient form of conservation. In PNG, among the Iatumul of the Middle Sepik, the Indopacific Crocodile was considered the creator of everything and its skull in the men’s house received regular offerings of betel nuts. The crocodile is often featured in the traditional carvings of the Sepik as well as among the Asmat and the Kamoro of the south coast of Irian Jaya. In Etna Bay, I have recently seen crocodile skulls set in rock niches a few meters above the water, with offerings of betel nut and food in porcelain plates.
Deifying and worshipping crocodiles and making offerings to them is perhaps one way humans try for some protection from the animal. Before large-scale hunting and near extinctions in many parts of the world starting in the 1950s, many human lives were lost to these efficient killing machines. A missionary on the north coast of Irian Jaya reported 62 villagers killed or maimed by a rogue crocodile in the 1960s. On the south coast, a similar beast was held responsible for 55 human deaths before its long career was ended in 1970. These were undoubtedly Indopacific crocodiles, as those responsible for a huge massacre of Japanese soldiers in 1945, described by the Australian Bruce Wright: ‘...scattered rifle shots in the pitch black swamp punctured by the screams of wounded men crushed in the jaws of huge reptiles, and the blurred worrying sound of spinning crocodiles made a cacophony of hell that has rarely been duplicated on earth. At dawn the vultures arrived to clean up what the crocodiles had left...Of about one thousand Japanese soldiers that entered the swamp of Ramree [Burma], only about twenty were found alive.’
Extinctions and future hope
While in former times various part of the crocodile were used for magic, religious purposes, medicine and food, a balance was kept and the animals were not endangered. The fad for crocodile skin products started after the American Civil War, for shoes, boots, saddle bags and belts. Not all crocodiles wear skin ideal for these and other products, but the belly skin of many species can be used with proper processing if top quality is not paramount. While the back of any crocodile is useless due to the bony plates embedded in the skin, the belly does not have this protection and thus suitable for tanning into leather. Of the 22 crocodile species in existence, at least 15 are currently exploited for their skins. The common caiman now accounts for 60 per cent of the trade in terms of numbers, but not nearly so much in monetary value due to its low quality. The highest prices are fetched by four species: the American Alligator, the Nile Crocodile and the two species found in our island, the Indopacific and the New Guinea Crocodile. Perhaps up to 40 per cent of the legal, ‘classic’ hides come from the last mentioned species. They receive a measure of protection in that legal skin size is restricted to the 18 to 51 cm. (seven to twenty inches) range for the belly width. This measure puts off limits the large breeding males and females, along with the juveniles. (In the wild, it takes eight to fifteen years for adults to reach sexual maturity at 1.8 to 2.7 meters, surpassing the 51 cm. belly width.) For leather goods and shoes, best species are the Indopacific, Siamese, and Nile crocodiles (the latter from Tanzania and Madagascar) since these are medium or small-scaled and have no osteoderms in the belly and the flanks. The classic belly hides either lack bony osteoderm buttons or have buttons which can easily be decalcified and removed during tanning so that scales can be burnished to high glaze required for haute-couture leather accessories.
Historically, the crocodile skin tanneries were concentrated in France and Italy, with lesser centers in the United States and Spain. Now, Japan also processes its own skins in large quantities for the luxury market. PNG’s traditional markets were France and Japan, recently expanded to Germany, Italy, Korea, Taiwan and the United States. Late 1980s prices for top-quality handbags ran from $1500 to $3000, shoes from $600 to $800 and belts in the $300 range. In early 2001, luxury stores in Shanghai were selling branded French ladies’ crocodile skin handbags for $5000 to $20,000. A fairly recent development in crocodile products has been the use of their gonads for musk and urine used for manufacturing perfume. Crocodile meat, long sought by men of Asia, has now become a valued product in Australian restaurants as well.
If crocodiles are not to be wiped out from earth for their skins, conservation must be practiced for the endangered species, along with commercial farming and ranching.
The raising of crocodiles in captivity is a tricky business on either farms (captive bred) or ranching (raising from eggs or juveniles gathered in the wild). The help of zoologists and experience has enabled commercial production to meet a large percentage of the market demand for the skins. The most successful crocodile farms are in the US (where in Louisiana Cajun music is piped in to the animals to decrease stress trauma from disturbances such as pen-cleaning), Australia and Papua New Guinea. The Northern Territory Management Plan allows the raising of 4000 Indopacific Crocodiles from two river systems, and up to 2000 of the endemic Johnson’s per ranch each year. On the various farms and ranches in Australia, we can find a total of some 16,000 Indopacific Crocodiles (data from late 1980s), a significant portion of the country’s wild population, thus a positive contribution to conservation. In PNG, a company called Mainland Holdings shipped all of its stock by air to its ranch at Lai where a measure of success was achieved thanks to very exact temperature control, to within half a degree Centigrade, thus controlling the sex ratio. In the late 1980s, there were some 28,400 crocodiles at this ranch, its success depending on feed from the business’ nearby poultry operations.
During the 1950s, the hides of some five to ten million crocodile hides, along with six to eight million caimans were used in commerce. By the 1980s, this overkill calmed down to between 1.5 to 2 million skins a year, of which over one million comes from the Common Caiman, mostly by illegal poaching in South America. While poaching has been brought under much better control in the past, largely thanks to quotas, import checks and restrictions, the main threat to many crocodile species is habitat destruction. This is certainly the case for the Indopacific Crocodile, now rarely found in India where it used to thrive.
The Crocodylidae family consists of three sub-families with 8 genera and 23 species:
1. Gavialinae, a monogeneric, monospecific family, characterized by a long and extremely slender snout, found only in India. Common name: gharial.
2. Alligatorinae, with four genera, each with two species, including the alligators and caimans.
3. Crocodylinae: these are the ‘true’ crocodiles as well as the ‘false’ gavials, with a total of some 14 species. These differ from the alligators in that the fourth tooth in the lower jaw projects when the jaws are closed, the ‘toothsome look’ of the fierce beats they are. The alligators’ fourth lower jaw tooth fits into a pit in the upper jaw, so they are not seen when the jaws are closed. Aside from crocodiles, this group includes a dwarf crocodile and a false gharial.
The Indopacific and the New Guinea crocodiles
Just how many species exist in New Guinea still needs some research. While the Indopacific (also called the Estuarine or Salt Water Crocodile), Crocodylus porosus is accepted by all herpetologists, there is problem with the fresh water species. For long it was thought that both the north and south coast animals were the same species, Crocodylus novaeguineae. But doubts have now been raised about this and the southern crocodile might be a different - and new - species.
There is no question that the Indopacific is the largest crocodile in the world, but just how large? An unconfirmed record has it at 10.1 meters, from a specimen caught in the Bay of Bengal in the 1930s. This certainly an exaggeration, but rational scientists say that an eight-meter length is possible, although verifiable, accurate records ‘only’ go to seven meters. Big enough, especially when weight is also taken into consideration. One six meter male weighed in at over one and a half tons. (By contrast, the next largest species, the Nile Crocodile, reaches a mere 6.5 meters and a top weight of ‘only’ one ton.)The species is the most marine of all crocodiles, sometimes seen far out at sea. Their swimming abilities are responsible for the wide dispersal of the species, from India to the Solomon Islands, making the species the most widely distributed one on earth.
In most of its range, the salt water crocodile has been greatly reduced if not eliminated due to over-hunting or loss of habitat. It has the best skin (on its belly) for processing into items like shoes and handbags. While its numbers have been drastically reduced world-wide, New Guinea and Australia are the two last refuges where the animals still thrive. This is especially true for Australia where the animals receive efficient protection. The species’ numbers were drastically reduced during the large-scale hunting phase which began in the 1950s in New Guinea and peaked during the 60s and 70s. At first, expat hunters did most of the killing, then Papuans took over in places where motorized canoes could not travel.
The Indopacific crocodile is easily aroused, a fierce and aggressive beast. Some of the larger ones prey on humans. The elements of its attack are always silence, speed and surprise. The final rush to the victim has been compared to a Polaris missile erupting from underwater. Like sharks, they are rarely seen before striking. The Indopacific’s ferocious appearance is further enhanced by the largest tooth on each lower jaw (the fourth) protruding outside the skin to fit into a notch in the top jaw. (This is the distinguishing mark separating crocodiles from alligators.) In the Asmat area, a large male was killed in 1970, having been held responsible for 55 human deaths according the area’s missionaries. These crocodiles are not much nicer to their own species. Except for a brief period in mum’s care, juveniles are on their own. Their growth is rapid, initially often over a meter a year. This fast growth last for at least ten years, then slows down, but with growth still evident after 30 to 40 years. Little crocs better grow up fast and stay out of the way of the dominant males or be killed and eaten. Juveniles live in fresh water areas but sub-adults have to look out or be forced out by the breeding males. If so, they move into nearby more marginal, saline areas or have to find another tidal river until big enough to challenge the large males to battle.
The coloration of the estuarine crocodile varies greatly with age. Juveniles tend to a pale yellow with very distinct black stripes on the tail and lower body. This persists for several years, gradually fading in color and the bands eventually disappearing. Mature animals are generally dark with some tan or gray areas. There might be some dark bands and stripes on the lower flanks but these do not continue to the stomach area. In some regions a small percentage are hypomelanistic, meaning much lighter in color.
The coloration is of very little help in distinguishing Crocodylus porosus from the similar-looking C. novaeguineae. The C. porosus has relatively small scutes and the scales are move oval than other species. The snout has nasal swellings, no hump but two ridges, all quite similar to the other species found in New Guinea. Aside from comparing skulls, the main external difference lies in the size and number of nuchal (neck) scales. The C. porosus has no post-occipital (behind the head) scales, or if so, there are only one to four small ones. The dorsal scales are usually continuous with the nuchals. These nuchals are enlarged and shield-like, arranged in two rows, separated from the parietal region by more than eight granular scales.
In the C. novaeguineae the dorsal scales are separated from the nuchals. In this species there are four to six post-occipital scales and four nuchal ones with two small lateral scales. This much smaller species grows only to a maximum of 3.5 meters in males and 3 meters in females. Its eyes show greenish irises. As its bigger cousin, the fresh water species shows dark banding on the lower body and tail, especially in juveniles. The snout is relatively narrower but the body is brownish to gray as the bigger species. All crocodiles in New Guinea are primarily nocturnal. The ranges overlap as the Indopacific or Estuarine Crocodile has been found as far as 1000 kilometers inland, in fast-flowing streams, although most are near the coast.
The vexing question of one or two freshwater species in New Guinea will not be resolved until the International Commission on Zoological Nomenclature in Geneva says so. Philip Hall has studied the differences and these are not yet overwhelming in justifying a new species status for the southern fresh water crocodile. In his 1989, article, Variations in Geographic Isolates of the New Guinea crocodile (Crocodylus novaeguineae, Schmidt) Compared with the Similar, Allopatric, Philippine Crocodile (C. mindorensis Schmidt), published in the scientific journal Copeia, he analyzes the differences: palatal structure, cervical squamation (scales) and reproductive biology. On the north coast the crocodile nests in the dry season while in the south nesting is during the wet season. In the north, the crocodiles have four occipital scales on the neck while in the south it’s four to six. In the north the clutches of eggs are larger and nests are usually made in mats of floating vegetation while in the south the nests are on land and the number of eggs per clutch is fewer but the eggs are significantly larger, by 5 centimeters. These differences have not been enough to warrant the designation of a different species.
Large-scale commercial hunting for all crocodile species in New Guinea started after World War II, peaking in the 1960s and officially restricted since the mid 1970s. According to regulations in both PNG and Irian, only belly widths of 18 to 51 cm. are allowed for the commercial exports of skins, corresponding to animal body lengths of 90 cm. to 2.1 meters. This leaves the mature adult populations undisturbed for the joys of breeding. For a while it was thought that crocodile farms were the answer to conserving the animals but the jury is still out on this one: in many areas the farms deplete the available wild stocks by capturing too many juveniles. And some UNDP studies show that there have been over-estimations on the availability of wild crocodiles.
X. The birds of New Guinea
New Guinea’s bird life is as spectacular as it gets. While the total number of species is not extraordinary, it is the variety and the uniqueness of the avifauna which is a justifiable source of Papuan pride. And it’s not only being home to the most spectacular species of them all, the birds of paradise: there are also huge crown pigeons, enormous cassowaries, large cockatoos, mound-nest building megapods and an almost endless variety of parrots and other colorful birds. The variety of birds rests on two factors. New Guinea retains the largest expanse of undisturbed tropical rain forest in the Old World where it is not unusual to find 150 species in a square kilometer. The other factor is elevation: new, steep, isolated mountains where endemics thrive in an unusual mix of vegetation. While the species richness may be low with rising altitude, the number of endemics increase. Some 190 species live above 500 meters.
Evolutionary scientists have no doubts that birds are descendants from reptile ancestors. The scales on bird legs are one of the proofs cited, along with a traceable evolution of reptilian body scales slowly transforming into the unique feature of birds: feathers. Birds also have wings (shared with bats) and beaks, making them the animal group easiest to identify and classify. There are some 9000 bird species in the world today, separated into 28 orders, based on anatomical similarities and differences. In the course of the evolution of animals with increasingly efficient body plans and organs, birds fall between the reptiles and the mammals.
The bats most closely resemble birds but wearing fur instead of feathers places them square into the category of mammals. Also bats have no beaks but are armed with teeth, absent in all living birds although some extinct ones had them. While bats came early in the course of New Guinea’s natural history, other mammal groups did not. As the island lacks placental mammals that live by foraging on the ground, some birds have filled this ecologically rich niche. In New Guinea we have three species of cassowaries, four genera of mound-nest magapods, three genera of huge and showy ground pigeons. a single hornbill but lots of smaller birds, all foraging on the forest floor for the main part of their diet.
In the strict numbers game, New Guinea can not compete with South America which can rightfully boast of an almost incredible number of 2671 species of breeding birds. This astounding number has its basis in geology, colonization and diversification. First of all, size counts: the South American land mass is much larger than New Guinea. And even before the closing of the gap with the North (and Central) American continent some three million years ago, the southern and northern land masses were close enough for extensive avian exchanges. For many bird species, the distances over water from Asia to New Guinea was just too far. Thus, isolation from a potential source of new genetic material, plus an unstable climatic history (forcing birds back to the lowlands in periods of glaciation) kept down the speciation of birds in New Guinea. Thus the fact that the original Gondwaland founder stocks of birds was limited (when compared to Laurasia), the geology, space, position and climate of South America allowed far more speciation than did Australia and New Guinea.
A recent count came up with 762 bird species on the island, with 652 (another one had 550) the number for Irian Jaya. Some are endemic to PNG and some to Irian. The western half of the island holds 65 species not found in the east. Out of these, 28 only live in off-shore islands. Of the 37 mainland species, most are confined to the mountains of the Bird’s Head or the central mountains. There are 76 families of birds on the island, all but three also found in Australia while 13 of the shared families are lacking in south-east Asia. There are at least 578 species of birds breeding in New Guinea and 40 sea birds offshore. Temporary visitors from the north number 56 while 34 species fly up from down under. New Guinea is the current center of bird distribution for several ancient Australian groups such as the cassowaries, the magapods, the fruit pigeons, lories and the fantails. The lack of several bird groups from Asia can be explained that birds are none too keen to travel overseas. While many are capable of sustained flight requited to cover the necessary distances, they are unwilling to do so over salt water.
Perhaps due to the lack of mammalian predators, there are many ground-feeding birds: three species of cassowaries, seven mound-nest building megapods, five large ground pigeons and a good number of forest rails. New Guinea is unusual in its many varieties of fruit and nectar-eating birds and there are more ground pigeons on the island than anywhere else. And, of course, there are the birds of paradise. The group is made up of a total of 43 species and ranges from the Moluccas through New Guinea and into Australia. But our island is the undisputed leader, with a whopping 33 species, including many endemics.
The leading attractions of the New Guinea avifauna have all radiated and evolved in isolation within the Australian-Papuan area. These include the families of the birds of paradise, the bowerbirds, the cassowaries and many a genera of pigeons, parrots, honeyeaters and kingfishers. While New Guinea birds evolved mostly in isolation from Asian tropical forest habitats, some groups have speciated enough to account for the (relative) richness of ground feeders, fruit-eaters and nectar-feeders while not doing so well as specialized insectivores. Thus while New Guinea birds are predominantly of Australian stock with local survivals of old groups which have become extinct or almost so on the larger land mass. The relatively recent speciation on New Guinea has already produced one of the largest and definitely the most unique avifauna of the tropics world-wide.
Habitat specialization is a definite factor in the recent speciation. For example, the MacGregor’s Bird of Paradise, found in only in the subalpine forest with the conifer Dacrycarpus compactus; the Greater Melampitta in limestone sinkholes and Mottled Pitohui in annually flooded alluvial forest; Anas waigiuensis in fast flowing clean rivers above 500 meters; alpine meadows are home territory for the Anurophasis monorthonyx and the Lonchura montana; bare rock slopes and cliffs for the Snow Mountain Robin, Petroica archboldi. The famous author (Guns, Germs and Steel, The Third Chimpanzee) Jarred Diamond is an ornithology specialist among his many talents. In 1981 he discovered the home of what had been called the ‘nearly mythical’ home of the Golden-fronted bowerbird in the very little explored Foja Mountains in the north-west part of the island.
Some birds are fussy eaters and specialize in a very particular diet. For example the fruit of the Chisocheton lasiocarpus and the Dysoxylum pettigrewianum (Maliaceae) trees are exclusively eaten by Birds of Paradise, and the fruit of Myristica sp. (Myristicaceae) eaten predominantly by this same group. Podocarpaceae seeds only germinate if passed through gut of cassowary. For example, the Casuarius bennetti is responsible for the germination of the submontane tree, Aglaia sp. whose range may much be reduced if cassowaries are not present. Other birds build or live in specialized nests. None come close to the elaborate and colorful spreads of the bowerbirds, but the Buff-faced Pygmy Parrot usually makes its home in cavities of termite nests. The Rufous Babbler builds domed, two-meter long nests hanging from the thorny Calamus rattans.
Most New Guinea endemic birds are found at higher elevations, with far fewer plant species, as these ecosystems are best suited than the tropical rain forest for dietary specialization and to isolate competitor species. While New Guinea has many endemic bird species, on the family level almost all are represented in Australia: of the 66 families of birds on the island, only four are not present in Australia. Of all the Aussie bird families, 27 per cent are endemic to the region, with this percentage increasing to 42 per cent for passerines. (Passerine birds, in the Order Passeriformes, make up more than half of all birds now living. The name comes from the Latin word for sparrow. The order is made up of small or medium-sized birds, mostly songbirds with grasping feet where the first toe is angled backwards.) The differences which exist between Australian and New Guinea birds is based on relatively recent evolution and speciation. A few birds in New Guinea are relict survivors of old Gondwanaland forms which have died out in Australia. But New Guinea woodland birds show lower species diversity than north Australia, at least partially due to the fact that the climate at low elevations in New Guinea during the last glaciation (some 15,000 years ago) was more arid than the land the corresponding section of north Australia which is now on the south side of the Torres Strait and the Arafura Sea.
Taking a more systematic look at what makes the assemblage of New Guinea birds quite unique, we have several outstanding major groups. The three species of cassowaries, all endemics, are characterized by a bony casque and grotesquely large, long wattle in adult males. The faces and necks are bare and show a gamut of colors: blue, red, orange and at times yellow. They feeds almost exclusively on fallen fruit. The birds can reach 1.7 meters in height and weight up to 60 kg. Their shiny black, coarse, shaggy plumage is used in many Papuan body ornaments.
Magapod birds, with 12 species in Australasia, specialize in building huge domed nests of vegetation, meant to generate heat when rotting, incubating the eggs inside. There are two groups of these megapods in New Guinea: the scrubfowls with two species and the bush turkeys represented by five species. The bowerbirds built smaller but much more colorful ground nests with tastefully arranged flowers, berries and plastic or anything else available. No one has accused them of being color-blind. The ordered displays remind one of carefully constructed, harmonious Japanese gardens. There are eleven species of these Australasian birds in New Guinea.
Parrots, lories and cockatoos boast of a grand total of 337 world-wide species, with their greatest evolution development in Australasia, especially in New Guinea. Their powerful flight muscles allow them to travel long foraging distances. Very short legs are specialized for scrambling around foliage. The large heads are equipped with strongly downcurved often massive beaks for chewing open tough seeds and excavating nest cavities in trees. They range in size from Pygmy parrots of 8.5 cm. to Palm Cockatoos at 64 cm. Cockatoos are the largest of the New Guinea parrots, with three species. All of them are crested. and are either completely white or black. Their vocalizations can most kindly be called raucous, powerful, loud screams with no musical qualities whatever.
The honeyeaters are the largest family in the New Guinea region, an Australo-Pacific group which even reaches Hawaii. There are a total of 173 species, of which 65 are found in New Guinea. they are extremely diverse in coloration, size and habits. The group includes the large, crow-like Helmeted Friarbird as well as the tiny Pygmy Honeyeater, one of the smallest songbirds anywhere.
Pigeons and Doves make up a worldwide family with 299 species. The greatest diversity in size, form and ecology is found in New Guinea with 45 species.
These include the huge crowned pigeons with spectacular fan-shaped crests. Unfortunately for them, their large bodies are quite fleshy. The birds’ coloration and habits make them easy to spot, thus facile prey for Papuan hunters.
While hornbills are split into 45 species, all in the Old World, there is but a single one in New Guinea. This Blyth’s Hornbill, a large 80 cm, black and white customer, with a typically huge conical bill. It feeds on fruit and flocks when not breeding. The nests in rainforest tree hollows where female sealed in during incubation and frequently fed by her faithful mate. In many areas of New Guinea, these are the easiest birds to spot, especially in the early morning and late afternoon when couples or small bands fly overhead with whooshing, steam-engine train sounds.
Birds of Paradise are just too colorful and different to enable easy characterization. The breeding males parade around, flipping and showing off on regular leks display courts high in the trees. Many shine with iridescent colors in exotic combinations. Long, modified, erect head or pectoral feathers sprout from odd parts of their anatomy. This is technically called dimorphous (different for each sex) nuptial plumage. The non-dimorphous species are monogamous and dull but both attend the nest and their young while the showy males stick around only for sex. (for a separate section on Birds of Paradise, see below)
As most of the scientific literature on New Guinea groups overviews of birds by eco-systems, we will follow this practice.
1. Mangroves. There are at least 27 breeding or migratory residents species in this ecosystem, with many visitors coming to feed from the seashore or the lower part of the tropical rain forest. Six of the resident species are found only in the mangroves: the Mangrove Kingfisher (Halcyon chloris), the Mangrove Warbler (Gerygone levigaster), the Rufous Fantail (Rhipidura rufifrons), the Broad-billed Monarch (Myagra ruficollis), the Mangrove Robin (Poecilodryas pulverulenta) and the Black-tailed Whistler (Pachycephala melanura). Unconfirmed but likely, we might add the Red-headed Honeyeater (Myzomela erythrocephala). Two of the seven New Guinea mangrove endemics also reside in the mangroves of Asia: the Mangrove Warbler and Mangrove Kingfisher. However, of the 27 resident species, far more are found in the north Australian mangroves: 24 have been confirmed.
2. Rivers, lakes and marshes. The birds in these habitats are completely Australian, both in genera as well as species. The Australian pelican is a regular winter visitor as well as making its way to New Guinea during periods of drought.
3. Rainforest. As the Australian continent drifted north from the temperate to the tropical area, the forest flora changed from temperate to hardwoods and desert plants. This took place during the early Tertiary Period as the Australian and New Guinea-to-be birds were evolving. The climatological and accompanying vegetation changes eventually produced the rainforests now found in Queensland and New Guinea. Speciation in the island’s rain forest has made New Guinea the center for several important bird groups:
cassowaries, magapods, fruit pigeons, lories, longrunners, fantails and birds of paradise along with several groups of honeyeaters and the berrypickers.
4. Grasslands. New Guinea has two main types of elevation-dependent grasslands: midmontane from 600 to 2000 meters and alpine, above 3000 meters. Fires set by man (for hunting, then agriculture) are at least partially responsible for these grasslands. The two types of grasslands support very different bird communities. In the alpine area we have only a few but very interesting species: the Nankeen Kestrel (Falco cenchroides), the Snow Mountain Quail (Anaurophasis monorthonyx), the Brown Quail (Wynoicus ypsilophorus), the New Guinea Pitpit (Anthus gutturalis), the Island Thrush (Turdus policephalus), the Tawny Grass Warbler (Megalurus timorenesis), the Snow Robin (Petroica archboldi), the Alpine Finch (Oreostrusthus fuliginosus), the Western Alpine Mannikin (Lonchura montana) and the Eastern Alpine Mannikin (L. monticola). These species are endemic, either as genera (the Snow Mountain Quail and finch), or species: pitpit, robin, two mannikins) or subspecies (the kestrel, the Brown Quail, thrush, and grass warbler). During the Pleistocene, starting some 600 million years ago, these grasslands at times covered a much area, thus more space in this habitat and a wider distribution of grassland bird species.
5. Lowland and hill forest birds. The composition of the birds in these eco-systems partially depends on the area’s geological history and current geography. There are three major tropical rainforest areas in New Guinea: on the south, from Etna Bay to the east, the Bird’s Head and in the north the contiguous Mamberamo, Sepik and Ramu basins. All of these were connected by coastal forests which disappeared during the Pleistocene when reduced rainfall replaced large chunks of rainforest with savannah vegetation.
The southern lowlands hold 12 endemic species, with four additional ones shared with the Bird’s Head. These 16 species include a cassowary, a scrub turkey (Talegalla sp.) a crowned pigeon (Goura sp.), a lory (Chalcospitta sp.), a pygmy parrot (Micropsitta sp.) a fig parrot (Psittaculuiristris sp.), a triller (Lalage sp.) and two birds of paradise.
The northern lowlands show 10 species absent from the other similar areas of the island, while sharing seven species with shared with the Bird’s Head. The westernmost part of New Guinea, the Bird’s Head peninsula shares four endemics with the southern forests and seven with the northern ones.
The best examples of lowland genera include fruit pigeons (Ducula and Ptiliopsus spp.), crowned pigeons (Goura spp.), lorries (Lorius and Chalcopsitta spp), the Palm Cockatoo (Probosciger aterrimus), the Electus Parrot (Electus roratus), along with kingfishers, pittas, cuckooshrikes, monarchs, starlings, mynas, manucodes and the King Bird of Paradise (Cincinurus regius). Most of the lowland species spread to the cooler lower montane elevations, to over 1000 meters.
The largest and smallest of New Guinea’s birds live in the lowlands: the
Double-wattled cassowary, Casuarius casuarius at 65 kilos, is by far the heaviest of any land animal on the island while the Pygmy Honeyeater weighs in at just 5 grams. Most of large fruit pigeons concentrated in lowlands. The largest and smallest parrots are the cockatoo Probosciger aterrimus 1125g and the pygmy parrot Microspitta pusio 13 g.
In general, high altitude, smaller body: smaller birds with higher surface-to-volume ratios would suffer more from cooler climates and higher altitudes. The Dwarf cassowary, Casuarius bennetti at one meter and 35 kg a notable exception to this trend, as it invades the forested habitats.
6. Montane birds. Some 190 species or about 33 per cent of New Guinea’s total of 570 resident species, are restricted to the montane environment, running from 500 to almost 5000 meters.
Tropical birds are unique in that the communities have many fruit-eaters as well as large numbers of nectar-feeders. In New Guinea, the fruit pigeon genera Ducula (11 species) and Ptilinopus (14 species) eat large fruit, commensurate with their size. Many lorries feed almost exclusively on nectar from flowers.
Classified according to their main food sources, New Guinea birds primarily insectivores represent the most important segment of all the communities, with a fixed 52 per cent. This is true even as the forest stature declines with altitude, along with insect availability and thus bird richness. Fruit-eating birds show a decline with altitude while seed-feeders, always the smallest proportion of the island’s avifauna, increase in species number in the highest zones as the alpine grasslands are an abundant source of seeds. With a rich assemblage of flower-bearing shrubs in the higher zones, the nectar-feeders increase in diversity as well. However, for all birds, competition for the same food source has a great effect on distribution.
While not nearly as spectacular as Birds of Paradise, the kingfishers merit special mention because New Guinea and adjacent islands hold the largest concentration of species: 26 out of the world total of 86. This plus the fact that an excellent book exists on these birds. (Knowles, 1995) Plus the fact that one particular species is much beloved by our Aussie friends.
Kingfishers do not much merit this name. Although it is true that some of them do fish, most don’t. But a few rainforest species have evolved from feeding on the forest floor to fishing in open freshwater. One species, Ceryle rudis, even goes out to sea several hundred meters, hovering prior to swooping down in its fish prey. The species does not live in New Guinea. Kingfishers range in size from 10 to 48 cm.
These birds are all in the family called Alcedinidae. They are thus part of the Order Coraciiformes which also includes bee-eaters, rollers, hornbills and marmots. The Alcedinidae family of kingfishers are subdivided into three subfamilies, of which two have representatives in New Guinea. The subfamily Alcedininae has five species in New Guinea, one the genus Ceyx and four in the genus Alcedo. The rest of the island’s species are all in the Dacelonidae subfamily. These include 55 medium to large (for kingfishers) birds, none dependent on water for their habitat. They feed on insects, grubs, lizards and small vertebrates, including an occasional snake. The genus Tanyspera, with six species in New Guinea and adjacent islands, is distinguished by the exceeding long tail, some 20 cm. with no apparent function, except perhaps to impress females. The only species in the genera Melidora and Clytoceyx live in New Guinea. The first one has a hooked bill, the second a shovel bill. Most of our species are in the genus Halcyon, with 10 out of the 35 species existing world-wide.
The genus Dacelo is justly famous for being host to the kookaburras, of which three out of the four species are Papuan. The D. tyro lives on the south coast and nearby islands, in the dry savanna habitat. It is entirely insectivorous. The D. leachii, of open woodland preference, is shared with the northernmost top of Australia’s Cape York Peninsula. Australia’s treasured bird, often heard on the radio, is the Laughing Kookaburra, Dacelo gigas, also known by various imaginative and humorous epithets like Laughing Jackass, the Alarmbird and the Breakfast Bird. Its’ long, wonderful call is most frequent at dawn and dusk with choruses often taking up an initial call. The singing of a duet or by family group appear as a means of strengthening social bonds; sudden outbursts of song happen when unusual event takes place: fledgling successful in leaving nest or the capture of large snake or other prize. While this bird has not graced New Guinea with its presence, we have a similar friend in the Rufous-bellied Kookaburra, Dacelo gaudichaud. No Aussies have made up fun names for the species. It is a woodland bird in canopy of deep forest, forest edges and bush of secondary growth, ranging from sea level to 1000 meters, but occasionally higher, to 1300 m. It is common at lower levels, but infrequent at higher elevations. The size ranges from 28 to 31 cm. The male displays a dark blue tail, female’s tail being rufous;. It feeds mainly insects, but also earthworms and small lizards. The species is very aggressive to other birds that invade its territory. It forages in pairs and keeps a very distinct territory. It is highly vocal, with a loud ‘chok’, often repeated, likened to the barking of a dog. The bird also calls with a fast series of tok-tok-tok”. Its repertoire also includes a loud, dry, descending laugh-like call, similar to D. leachii, often taken up by other birds in the vicinity and usually accompanied by cocking of tail. The species lives in chambers excavated in a tree or a termite mound. It nest up to 40 m. above ground laying two eggs and nesting from August to January. (Knowles, 1995) The tail feathers of this bird were used long ago by the Amung tribe as a decoration for a medium of exchange made from beeswax. Sometime after the turn of the 20th century, it was replaced by cowrie shells as money. These shells are still occasionally used in some bride price payments but have been almost entirely replaced by the Indonesian national currency, the rupiah for all transactions.
Birds of Paradise
In the annals of sexual display, no family has gone to such trouble to attract females. In the views of strict Puritan ethics, no family wastes so much valuable time in the pursuit of sex. Yet, ironically enough, this profligate family has been named after the ultimate aspiration of the dour, colorless God-fearing Christians, their ultimate reward after a lifetime of toil and trouble, of self-denial: paradise. In scientific parlance, this comes out as Paradisaeidae, the Birds of Paradise. In human terms, it is as if the class of wealthy playboy in their red Ferraris, mansion and orgies, never settling down and popping Viagra in his old age, were to be thus named. With no irony intended. There is plenty of irony however in the human female’s use of Bird of Paradise male plumage to attract human males from the 1880s to the 1920s when conservation measure put an end to the slaughter. The irony on top of that one is that the Birds of Paradise were never really endangered. Younger males without the sought-after nuptial plumes, are perfectly capable of reproduction, as much as human teenagers. It takes five to seven years to develop fully adult plumage and until that time they resemble females so much that they can not be told apart visually. But the female birds can tell and will mate with them if there are no magnificent males around.
But the animal world and its evolution is not governed by self-imposed (or God-imposed) human rules. The basic regulation here it that males and females do whatever it takes to transmit the maximum number of their genes into the next generation. The mantra ‘survival of the fittest’ has many ramifications. In this case, it means a set of showy plumes on males of several genera (but not all, by any means) of the Birds of Paradise, birds which have no survival value and are more of a hindrance than anything in escaping predators or seeking food.
The two scientists most closely associated with the nailing down the natural selection process, the mechanism for evolution, drew inspiration from the Birds of Paradise. Alfred Russell Wallace, who spent eight extremely productive years in what is now Indonesia (without having to renew his visa!). He hit upon the idea of natural selection while recovering from an attack of malaria and promptly wrote about it to Charles Darwin who had not published anything about evolution at the time. Wallace was low in the British pecking order and thus history remembers Darwin as the father of the theory of evolution. Be that as it may, Wallace was a field naturalist, among the very best, and his book The Malay Archipelago still stands among the cognoscenti as the best book written on Indonesia, considering both style and content. His observations of the leks (display locations for birds) of the Greater Bird of Paradise in the Aru archipelago created much interest among naturalists in Europe. Later, the now armchair naturalist Wallace (he had done his field exploration aboard the ship Beagle in his youth) drew on the important example of the Birds of Paradise in his treatise on sexual selection, the crucial keystone of evolution.
Birds of Paradise feathers and dried skins had been known in Europe since the Portuguese first sailed through New Guinea waters. Indeed, it was Linnaeus, the father of scientific nomenclature (naming) who baptized the relatively common Greater Bird of Paradise as Paradisaea apoda. The species name apoda, meaning without feet in Latin, was given because all skins sent to Europe had their feet cut off prior to shipment. It was thought that these birds never alighted on earth, whence the paradise designation for the family.
Of all the animals in New Guinea, birds have received the most attention and we can be reasonably certain that none have been missed in the various studies. There is no question that the Birds of Paradise are centered in New Guinea which holds 38 out of the 42 existing species. Outside of New Guinea and its satellite islands, only two species are endemic to the Moluccas, two riflebirds are found only in Australia, and two species are shared between New Guinea and Australia.
The Paradisaeidae is divided into two subfamilies, the Cnemophilinae and the Paradisaeinae. The first division includes the wide-gaped (gape means the mouth and fleshy corner of the bill) Birds of Paradise. They do not have dexterous feet, build domed nests, and they are almost exclusively frugivorous. The second subfamily encompasses the typical Birds of Paradise. A finer division is based on four clades or lines of evolutionary descent. These are the flagbirds, the riflebirds, the sicklebirds and the sticketail/Paradisaea cluster. All are well defined and differentiated by their plumage and body morphology. The flagbirds display erectile occipital (head) plumes. The riflebirds share very distinctive metallic breast-shields and static, upright displays. The sicklebirds are different due to their unusual curved bills and chest plumes framing the head during display. The last group is a bit more complicated and thus re-divided into two categories. The sickletails show a central pair of tail feathers modified into thin, curved wire-strands, iridescent green lower body plumage and a dorsal set of red feathers, along with bright blue legs. The Paradisea cluster, the typical Birds of Paradise, are united thanks to both filament-like flank feathers and tapered tail plumage. This last group is also knows for its powerful and dexterous feed, of great use in feeding.
Birds of Paradise vary greatly in size, from a tiny body length of 15 cm. and 50 g. weight to 45 cm. and 450 g. for the Curl-crested Manucode male. The Black Sicklebird measures over a meter if we include his magnificent tail feathers. The sicklebirds are among the best examples of the unusual degree of sexual dimorphism in the Birds of Paradise. The term means a marked difference between males and females in body size or some other physical features. This is most evident in our group in the males-only nuptial feathers. Plumes-wise, females are plain-Janes, although very desirable ones. Of the 42 species in the family, 33 are sexually dimorphic - and polygamous. Only the manucodes, forming a very distinct clade in the family, are monomorphic (the opposite of dimorphic) and monogamous. They are also the only known ones to extend biparental care to the eggs and hatchlings. The others, magnificent males, are great show-offs but useless as caring fathers. But the female can manage on her own, thank you very much. Unlike the more intelligent of the human females who tend to choose breeding partners (as opposed to safe-sex flings) on the basis of intuition as to follow-up commitment.
Magnificent nuptial plumes are the males’ prime enticement, although females also look for other factors before their final decision (see below). No other birds display such an array or coloration and feather modification, with the possible exception of the pheasants (remember the peacock). The shape and variety of these special feathers, as well as their points of origin, leaves only amazement in its wake. Some sprout far from the head, or the chest or are shaped like long, recurved wires with decorated tips. Thus the birds of the genus Parotia sprout six wire-feathers from the back of the head, each tipped with a ‘flag; in the shape of a plume. The Cicinnurus genus shows similar wire-feather, a pair, coming out of its tail, each coiled into a graceful curves. In addition, the Cicinnurus regius, the King Bird of Paradise, tips these tail wire-feathers with a brilliant emerald-green disk. And to cap the show, we have the four most outstanding species of the Paradisaea genus with wonderfully colored splay of long flank or tail feathers, white and yellow in the P. minor, the Lesser Bird of Paradise, yellow and a rich brown for the P. apoda, the Greater Bird of Paradise, a magnificent reddish-orange in the P. raggiana, the Raggiana Bird of Paradise, flame-red in the P. rubra, the Red Bird of Paradise and a glossy, iridescent blue in the P. rudolphi, the Blue Bird of Paradise. As if this were not enough, the head feathers are stunning as well, in contrasting colors.
And the colors of some of the other species in the family are no less remarkable, with a kaleidoscope in the range of shades and hues, combined with a brilliant iridescence enhanced by light refraction. Given this magnificence, it is hard to believe ornithologists who tell us that these fantastic birds are just elaborate crows. They base this deflating assessment on the fact that Birds of Paradise are crow-like in average size, shape, strength, demeanor, powerful beaks and feet. Males also make harsh, crow-like sounds (the females are silent). These distinctive, powerful but always unpleasant (except, perhaps, to hunters and ornithologists). In the manucodes, the far-reaching sounds are produced by a physical modification of the trachea which has become enormously elongated, a unique feature among passerines, the perching songbirds.
Magnificent plumes and powerful sounds tend to attract predators, so males have to be on their toes (claws?) to be extra-careful of dangers. These come in two varieties: snakes and birds of prey. The forest habitat has enough large arboreal snakes to cull out the careless males: several pythons (see under snakes, above) along with an assortment of hawks and eagles. The New Guinea Eagle, Harpyopsis novaeguineae, is most dangerous of these for our fine-feathered friends, along with the Brown Tree Snake, Boiga irregularis. Females are much better off: no colorful plumes or brash noises. Plus the fact that female plumage in this family resembles that of the Hooded or Variable Pitohui whose skin and feathers carry a highly toxic alkaloid which serves as a chemical defense against predators as well as parasites. Neither sex escapes the blood parasites, microfilia. These unwelcome guests influence male courtship display and vigor. While showy plumage is definitely a signal of heritable fitness in males, the females will recognize and reject those with heavy parasite loads which impair the production of bright plumage as well as sapping energy. (Frith, 1998).
Even taking the predators large and small into consideration, we still agree with Sir David Attenborough when he remarked that New Guinea was indeed a paradise - for birds. His reasons are two fold: competition and predators. On this island we have very few vegetarian or insect-eating placental mammals (well, aside from a fair number of rodents), with no monkeys to grab fruit or squirrels to gnaw on nuts (don’t forget the rodents). Thus, says Sir David, the female Birds of Paradise can collect fruits with ease and can rear her chicks unaided. He also points out that New Guinea holds no large mammalian carnivores, thus the male birds are not dangerously encumbered by their huge plumes. (quoted in Frith, 1998).
Birds of Paradise are mostly confined to the rain forests, with a number of species in the lowlands but most in the montane forests in the 1000 to 2000 meter altitude range. Most of the restricted-distribution species are in the mid-montane zone, defined here as between 1200 and 2500 meters. This altitude gradient holds nine resident species with additional vagrants. Thus the main ecological factor in the species distribution is the altitude-determined habitat selection. This offers closely related species the opportunity to avoid competition while establishing geographical sympatry, meaning occupying adjacent elevational zones without significant direct contact between populations. Elevation as the most important ecological sorting that permits adaptive radiation of the Birds of Paradise. The primarily lowlands genera include Manucodia, Ptiloris, Cicinnurrus, Selcucidis and Paradisaea. These genera include the most widely dispersed ones to nearby islands and Australia. The King Bird of Paradise, Cicinnurus regius, has the widest lowland distribution, found in most of the periphery of the island (except where hunted out) while the largest elevation range is attributed to the Curl-crested and Trumpet Manucodes (Manucodia comrii and M. keraudrenii) found from sea level to some 2200 meters. In the high cordillera, from 3200 to 3500 meters (but also up to 4000 meters) the most wide spread species, MacGregor’s Bird of Paradise (Macgregoria pulchra), found in the subalpine woodlands. While spread out over the entire length of this cordillera, a huge extension which crosses the body of New Guinea, the individuals are only very slightly differentiated in spite of the enormous east-west gap. This bird’s distribution is only limited by its favored tree, the gymnosperm Dacrycapus compactus, a conifer. (Frith, 1998)
The Birds of Paradise began their evolution after Gondwanaland split up and while Australia was drifting to the north, with much of New Guinea still attached. They are among the descendants of the old, endemic Australo-Papuan passerines, members of the corvid assemblage which includes monarchs, wood-swallows, whistlers along with the Birds of Paradise. (Coates, 2001). Our group is considered monophyletic, meaning that it comes from a single evolutionary lineage for the entire family, showing its cohesiveness. This is based on the cladistic principle of parsimony, meaning the simplest explanation possible which takes all the facts into account. The starlings and crows are the closest relatives, all descendants from the same stock. They all have erectile feathers above and behind each eye. Although the bowerbirds also hold to bizarre polygynous mating behavior, along with frugivory and shared locations, there is no relation as previously thought. Birds of Paradise, like crows, use their feet for feeding, probe for food with open bills and regurgitate food to their nestlings.
The Bird of Paradise family is one with the most restricted distribution of any in Australasian region. No other group with as many species in such a small geographical range. The group radiated in New Guinea, and never evolved any dry-habitat lineages. They speciated in wet uplands of central mountains over recent geological times and never to open woodland habitats, even during the driest climatic periods. (Frith, 1998) Thus as Australia drifted north and much of it became the desert it is today, the Birds of Paradise stuck to what was to become New Guinea, the wetter, forested section in the north. As tectonic forces pushed up the island’s mountains while the lowlands remained tropical even in the Ice Ages, New Guinea habitats became the milieu for the diversity and radiation of the various Bird of Paradise species.
The most important split in the family occurred some 18 to 20 million years ago when the Manucode and the Pardiseaea lineages each started to go its own evolutionary way. They still share a floppy, undulating flight, body morphology, strong legs, feet and claws. The basic lineages holding the Manucodes and the Macgregoria antedate the explosive radiation which split the Birds of Paradise into so many species. Unlike their much speciated cousins, these two groups are sexually monomorphic, pair-bonding, monogamous and refuse offers to hybridize. The genus divergence began some 4 to 4.5 million years ago, with the Cicinnurus going its way about 1.5 million years back. The fission of the rest, the sister species made up of some 25 species, took place less than 1.5 million years ago. Thus the Paradisaeinae subfamily are all from a recent, rapid and explosive radiation. (Frith, Frith, 1998). The proof is this is evident in the remarkable inter and intra-genetic hybrids which are most disconcerting to amateur bird watches (and sometimes professional ornithologists as well). Some of the offspring are spectacular by-products of this hybridization among the polygamous species. No other bird families have produced so many wild interspecific hybrid crosses. We thus end up with a single family of songbirds with extremes of monogamous and polygamous mating, sexual dimorphism, adaptive radiation in bill shape and size, courtship behavior, an incredibly high degree of subspeciation and hybridization. (Frith, 1998)
As in other animal groups, the dietary ecology shoves evolution by rewarding the efficiency of feeding abilities. This had led to a remarkable diversification of bill size and shape in the Birds of Paradise, indicating a range of diets and foraging methods. The group can be divided according to diet, which falls into three main categories: almost exclusively frugivorous, nearly completely insectivorous, or, more typically, a combination of these two sources of nourishment. Ornithologists have remarked on the close relationship between specialized frugivory and the evolution of the complex polygynous lek behavior and mating system of the Birds or Paradise.
Taken as family, the Birds of Paradise eat fruits of several hundred species, leaves, flowers and nectar along with insects, spiders and other arthropods, small frogs, and lizards. With no placental mammals such as monkeys competing for fruit and only the very recently evolved tree kangaroos up in the trees, birds have the rainforest fruit pretty much to themselves. Parrots are mostly seed-feeders as many pigeons. The essentially large, fruit-dependent pigeons (genera Ducula and Ptiliopus) are far less capable of manipulating fruit when compared to the dexterous-footed Birds of Paradise. Thus pigeons who have to take their time and loaf around the fruit-producing tree as less apt seed dispersers than our Birds of Paradise. Other animals good at seed dispersal are the cassowaries (fallen fruit only) and bats. But our family of Birds of Paradise are probably the most important seed dispersers in their habitats and the plants have rewarded them by producing highly nutritious fruit with protective structures that limit access to our fine-feathered friends. Indeed, the family has more species of seed-dispersing frugivores (34) than any other vertebrate group, with pigeons coming in a distant second (24) and not so efficient as they hang around too much and tend to drop the seed after digestion too close to the parent tree.
While trees need the Birds of Paradise for seed dispersal, our family never restricts itself to a single species. For example, the Macgregor Bird of Paradise specializes in the resin-rich, fleshy cones of the subalpine Dacrycarpus compactus, to the extent that this bird is not found in areas where the tree does not grow. But when the tree is not in producing, these birds have a range of other fruit for food. The most specialized food plants are the capsular species in which the bird must extract the edible ‘reward’ from its protective husk. Considerable dexterity is needed. Pandanus fruit is preferred by Twelve-wired Bird of Paradise while King of Saxony specialized in the fruits and false figs of the trees Timonius spp. of the Rubiaceae family. Some of the most popular tree with the Birds of Paradise include the nutmegs of the Meliaceae family, Myristica spp. along with Chisocheton spp. and Dysoxylom spp.; in the Araliaceae family: Gastonia spectabilis and various kinds of trees of the wide-spread Ficus and Schefflera families. (Frith, 1998)
In the main, frugivores tend to be more sociable, insectivores more territorial and solitary. Logical enough: there is plenty of fruit once a bearing tree is located but insects are far fewer in a single location. In most insect eaters both sexes attend and in many cases provide food to nestlings. It is assumed that arthropods provide the necessary calcium for bone formation, structural proteins which are critical constituents of tissues, organs and for feather production, along with the lipid energy necessary for growth. (Frith, 1998)
Display in the leks
There are still many inexplicable aspects to communal lek behavior. Why should so many males display together when only a very few will have the opportunity to pass their genes on in the process? On one instance cited (Frith, 1998) there were eight Lesser Birds of Paradise males all displaying in a lek, yet the alpha male performed 25 out of the 26 copulations. Were the rest voyeurs of prurient interest? How much frustration can a male take? Is it just practice and hope for better days ahead? Or is it that we tend to put an anthropomorphic slant on this particular aspect of bird behavior? The leks with the highest mating skew have the most males, as many or 40 or more. One rational explanation could be that females could be selecting not only for male nuptial plumage, but also for traits such as assertive and aggressive posturing and movements as a sign of health. Whatever the advantages, the lek mating system represents the most extreme form of polygynous mating system in the world. (Frith, 1998)
It seems that lek displays by the parotias have evolved in taking a ‘quantum leap’ from a simple ground clearing to one but decorated with specific items like natural chalk, brightly iridescent green elytra (wing case) of cetoniid beetles, sloughed snake skin, mammalian dung. It seems that females will carry these away during nesting season. Thus they thus take resources possibly of use to egg formation and nutrients. The better kinds of leks help the female assess the male’s fitness. Then the behavioral shift from court-based polygyny requires that males be ‘emancipated’ from duties at the nest. This requires reliance on a suite of food plants that produce nutritious fruit on a predictable schedule.
Not all Birds of Paradise perform their courting in leks. Indeed, out of the 42 species, only 13 favor communal courtship displays. Cooperative courtship is usually only in communally-displaying species. This typically involves two or more males performing synchronized communal display routine to a visiting female. However, the female will only mate with one of the performers. While male fights at leks are not uncommon, this is usually restricted to newly established sites. Older leks, with more males show less male aggression and more females visiting. Most species carry out courtship displays at traditionally (perennially used) sites. In polygynous species, adult males use traditional perches for at least some combination of advertisements, display and mating. Some males go to great lengths to show off, doing flips, leaps and all sorts of acrobatics. On the other hand, some adopt the communal static ‘flower pose’, hanging upside down, with lowed head. Thus the females have the opportunity to inspect and compare several males in the same static posture. These inverted males appear in an almost trance-like state, oblivious to distractions. Perhaps the female sees more in all this than the peeping-Tom ornithologists. It seems that many birds can perceive further into the ultraviolet band than humans, thus seeing colors we can not. So what seems already brilliant to us could be even more enhancing to the females birds. (Frith, 1998)
Prior to the displays, vocalization is of crucial importance for males to advertise their presence to potential mates. While harsh and definitely unmusical to human ears, there is a remarkable diversity of sound types in patters and qualities. There might also be a sexual attraction in the flight of some Birds of Paradise which produce conspicuous sounds. Some species perform dramatic display flights while controlling sound made by their wings.
One source states that the Birds of Paradise generally display in the dry season and nest at the beginning of the rainier one. This usually occurs from April to October, but there are many local climatological variations. Elsewhere, the same source states that
‘Generally breeding activity over New Guinea takes place during the seasonally heaviest rains, January to April, then picks up after rains recommence after driest period, October to April.’. (best to see all this: Ambua Lodge, Tari Basin, PNG??? Lorentz Park once I get things moving there???? ladders to get up to see leks???)
The must vulnerable time from predators for any bird occurs while still in the egg and just after hatching. Even with both parents fighting furiously, some predators are just too strong and will gobble the helpless chick embryos or hatchlings. With Birds of Paradise, it’s female-only nest care in most species, affording even less protection. Thus evolution in the family has led to a high egg to female body mass ratio and clutch sizes of only one or two eggs. The relatively large size of the egg shortens the nesting stage while clutches of one or two eggs are more quickly and easily replaced. Thus nest failure can result on several re-nesting during the breeding season. The birds spend some 60 to 80 per cent of their time incubating and watching over the egg(s). Once hatched, the chicks better grow up fast. The breeding season coincides with a period of abundance in both fruit and arthropods. In species depending on less nutritious but more abundant figs, both parents often feed the hatchling. If the fruit is rich in protein and lipids, or insects for an important part of the diet, one parent is enough. In the Raggiana Bird of Paradise, Paradisaea raggiana, the hatchling is ready to leave the nest at 20 days, having already attained three quarters of its mother’s size. In ten weeks it’s as big as mom.
XI. Mammals of New Guinea
Mammals are distinguished from all other animals by the presence of milk secreting glands and body hair which is present even in whales and other cetaceae, but only during early stages of their development. Their lower jaws are made of a single bone and which is articulated directly with the skull. They differ from birds and reptiles in having a diaphragm and non-nucleated red corpuscles; mammals resemble birds and differ from reptiles in being warm-blooded. They are set off from amphibians and fishes in the presence of amnion and allantois, along with the absence of gills. All mammals except the montremes give birth to live young. (Nowak, 1999)
The date of the earliest mammals have not yet been clearly defined: perhaps from the middle Jurassic, 165 million years ago; or from 225 million years ago. The monotremes fall into a single order, the marsupials into seven and the placentals in 20 orders. All mammals, including monotremes, marsupials and placentals, originated from a common ancestor, a small, nocturnal and insectivorous animal, which traces its own ancestry to the reptiles. The divergence of monotremes took place only some five to ten million years before the placentals and marsupials split off from each other, 120 million years ago. (Nowak, 1999)
There is no known reason for the divergence between the two major groups of mammals. Marsupials were once widespread in both the north and the south but now only one species lives in North America and in South America they are far outnumbered by placentals. It is only in New Guinea and Australia where they dominate today.
It was formerly held that marsupials developed in the northern hemisphere but then were restricted to a few southern regions due to the expansion of superior placentals. Current thinking does not accept the inferiority status of marsupials. Rather it states that in the south marsupials had far less room to evolve and thus had much more difficulty in achieving geographic distribution. While the marsupials have a smaller cranial cavity in relation to body size, their learning and problem-solving potential equals or exceeds that of some placentals. (Nowak, 1999) Marsupials have the advantage of investing much fewer physical resources during the very brief gestation, thus if the embryo is lost a second attempt at reproduction can be made more quickly and in better conditions than with placentals. The female marsupial’s commitment to her young comes after birth which follows a very brief period of gestation when compared to placentals who are unique among all animals in their extended gestation. The energy expanded by marsupials moms in rearing their young amounts to much more than for placentals, humans and elephants excepted. Gestation in mammals is measured in months rather than days as for marsupials. The placental young are born larger and the suckling period is much shorter than for marsupials. Contrary to popular belief, not all marsupials have pouches for their young. Small terrestrial marsupials do not have a pouch and in others this only develops during the reproductive season. (Nowak, 1999)
Base on body morphology, mammals are divided into some twenty eight major orders, 146 families and 4,809 species. (Nowak, 1999) Four kinds of mammals have members among the native animals of New Guinea: the monotremes, the marsupials, bats and rodents. And out of these two are really native to the Australia-New Guinea zone: the montremes and the marsupials. The bats, order Chiroptera, winged in from Asia during the early Tertiary Period, some 60 million years ago, soon after the evolution of this order. The rodents, order Rodentia rafted over from the west in the Pliocene Epoch, around 10 to 15 million years ago.
New Guinea hosts a unique fauna of mammals due in great part to its geological history. While Australia moved north in splendid isolation on its own tectonic plate, a group of mammals called marsupials evolved there. When New Guinea emerged from under the seas as Australia crunched up against the larger and tougher Pacific plate, it was colonized by these marsupials. Later, some 25 million years ago, cut off by rising seas, new species began evolving in New Guinea. When lower seas during the Ice Ages re-established a land connection to Australia, some mammals crossed this divide, but many did not, due to unfavorable ecological conditions in this intermediate zone. Very few mammals, and only those at or near the coasts, were identified and named during the first half of the 18th century. It was the Italian, Luigi D’Albertis who, in 1872, pioneered the zoological exploration of inland, montane, New Guinea, in the Arfak Mountains of the Bird’s Head Peninsula. The first systematic and comprehensive surveys began in the 1930s with a series of expeditions sponsored by the millionaire Richard Archbold (great name for an explorer!) for the Museum of Natural History in New York.
It is not easy to see any mammals in New Guinea: most are nocturnal (with the exception of day-active wallabies) and with a very healthy fear of man. There have never been any large native placental herbivores on the island and any large native mammal predator is conspicuous by its absence since the extinction of a relative of the Tasmanian wolf, Thylacinus (cynocephalus?) which died out perhaps some 30 to 40,000 years ago. The rugged interior terrain of the island, plus none too hospitable mangrove swamps, have long protected the indigenous mammals from scientific gaze. With modern communications and improving infrastructure, more and more animals are appearing on recent lists. But zoological investigations are still far from easy. The larger species have learned that survival means staying away from humans. The smaller ones live by remaining hidden. Finding and listing mammals usually requires considerable help from the local inhabitants.
The island as a whole was the last major geographical area on earth to be explored. Thus its animal life, including the mammals, were long unknown. Expeditions into the interior of the island only began in the latter part of the 19th century. Flannery (1995) makes an interesting chronological recount of New Guinea mammals: Otto Finsch came up with only 15 species in 1865, followed by Alfred Wallace’s 17 species in 1869. By 1906, the zoologist Jentink could list 40 bats, the same number of murids, 50 marsupials and monotremes along with two pigs. However, many of his species have turned out to be synonyms. Then between 1907 and 1990, 120 species were added. Flannery come up with 25 more between the first edition (1990) and the second one (1995) of his book on the mammals of New Guinea. Of course, the local inhabitants knew about these animals, but it took this tireless zoologist, who had excellent rapport with the tribesmen, to compile what is now the Bible of the mammalian fauna of the island. In the publication of his definitive second edition in 1995, he states that ‘many additional species will doubtless be recognized in the coming decade’. The 1995 list includes 212 indigenous species, 13 introduced and 15 extinct ones, with the living species only one fifth less than those found on the huge Australian land mass. But when Flannery compares area to species as ratios, he found that New Guinea was eight times more species rich than Australia but only half as rich as Thailand.
Just about all the new species were found and validated by Flannery himself. The totals include an equal number of rodents and marsupials, with about 60 in each grouping. But while the rodents are all of one family, rats and mice, the marsupial fauna is much more varied, with seven families and species ranging in size from mouse-like carnivores to the large, herbivorous kangaroos, Macropus agilis. Bat round out the numbers, with six different families on the island.
The last species of mammals to make the list was the Dingiso, a kind of tree kangaroo, eventually graced with a proper binomial name, Dentrolagus mbaiso. Flannery had seen a Papuan wear a headpiece made of a type of fur he had never seen. After inquiries he found the animal which enjoys a taboo protection from a part of the Moni tribe. This is probably the key to its survival as population pressures in the highlands have greatly intensified hunting. According to Flannery, at the latest count there were 212 indigenous mammals in New Guinea, 15 extinct species and 13 introduced ones. This total is only one fifth less than all of Australia and Tasmania combined. When indexed according to size, New Guinea is eight times as species rich as Australia while Thailand is twice New Guinea’s number. Well over half of the island’s mammals are endemics. (Flannery, 1995)
Flannery attributes the high mammal endemicity to the island arcs which were eventually absorbed into New Guinea. Separated be deep, open sea, the islands held their unique faunas. Parts of the Bird’s Head contains fauna evolved through 100 million years of isolation. The Australian land mass, along with much of what became New Guinea, has been isolated for the past 50 million years, after splitting off from Antarctica. The southern part of New Guinea was originally the leading edge of north Australia. It submerged, emerged, went down again to rise above to sea and re-connected to the continent. Then it was cut off once more with the connection restored intermittently over the past two million years. During the Ice Ages, there were 17 periods of heavy glaciation when a dry land connection existed. This was a broad plain of woodland and savannah, unlike the rainforests in northern Australia and southern New Guinea, making it difficult for many animal groups to cross over. Rain forest corridors, which would have made animal dispersal easy, were either very poor or non-existent. With the abrupt ending of the last Ice Age between 8000 and 10,000 years ago the land bridge was flooded with the Arafura Sea, a shallow body of water with a maximum depth of only 60 meters.
To sum up, the scattered islands which eventually became part of north New Guinea presented ideal places for species to develop and survive on such small land masses. This combined with an influx of mammals from mainland Australia. Then the rearing up of the high central mountain range added to the diversity of animals by creating new eco-systems requiring adaptation.
But what nature hath wrought was irreparably damaged by man. While humans might have arrived in the Australia-Papua area as long as 100,000 years ago, by 50,000 BC they were definitely settled. Australian mass animal extinctions date back to this time, with over 40 species of large monotremes and marsupials hunted out of existence. There was less damage in New Guinea, perhaps due to the rugged nature and the climate of the interior. But at least nine species of herbivores and one carnivore became extinct. Not a pretty picture, but at least New Guinea has the honor of having suffered less mammal extinction than any other area outside of Eurasian landmass.
While man can quickly and terminally hunt out various mammals, the greatest influence on the animals remains the general type of vegetation of their environment. Due to immigrants from Asia, New Guinea’s rain forest has but a few endemics. These include the forest wallabies of the genus Dorcopsis (terrestrial herbivores) with different species in the north, south-east and the south. Other endemics are cuscuses of genus Phalanger as well as the wide-spread spotted cuscus, Spilocuscus maculatus, with different subspecies in the north and south. There are also megachiropteran bats, aerial carnivores, and tree mice of the genus Pogonomys, arboreal herbivores. Add bandicoots of family Peramelidae (terrestrial omnivores) and striped possums of the genus Dactylopsila (arboreal carnivores). The majority of restricted indigenous rainforest species are non-Australian, reflecting the scarcity of this habitat further south and its abundance to the west. With the exception of fruit bats, the lowland jungles support surprisingly few mammal species. And fewer still are restricted to this habitat, with the exception species of Dorcopsis and possibly some Melomys, along with a few other rodents and some fruit bats.
The hill forest transition from lowlands to lower montane holds a few characteristic species such as the Black-spotted cuscus Spilocuscus rufoniger, the grey cuscus Phalanger permixtio and, on the South side of the island, the rare tree kangaroo Dendrolagus maschiei spadix. The grizzled tree kangaroo, Dendrolagus inustus and Spiny Bandicoot, Echympera clara are found in hill forests but only in the north-west while large echidna, Zaglossus bruijni spreads from hill forests anywhere to the alpine zone.
In the lower montane forest between 1000 and 2000 meters a different picture emerges. This is where the true montane fauna begins. In the foothills below 1000 meters Araucaria trees emerge above the canopy to attain 50 meters in height, followed by a zone of oak domination. Higher up Nothofagus, conifers, and the families Myrtaceae and Elaecarpaceae are common. Here plants of Gondwanaland origins are more abundant than at lower altitudes. And it is precisely here that this zone of the lower montane forest supports the most diverse mammal assemblages of New Guinea, along with the majority of species. Most lowland bandicoots are also found in the lower montane elevations, with Echympera rufescens and especially Echympera kalabu abundant just about everywhere. This ecosystem’s marsupials also include long-haired mountain cuscus, the larger ringtail possum, the Pygmy possum, the Mountain Striped Possum Dactylopsila palpator and the striped mountain bandicoots, Peroryctes longicauda and P. papuensis. Dorcopsis wallabies are not found away from lowlands, their place in mountains taken by much smaller Mountain Forest Wallaby, D. vanheurni. The common bush wallaby, Thylogale brunii, can be found anywhere from hill forest to the alpine zone, even above the tree line. Many montane species are widespread in the central mountains while a few restricted, as Pseudocheirus albertsi in the Bird’s Head and the northwest coastal ranges. Phalanger sericeus lives throughout the highland ranges, commonly called the High Mountain Cuscus.
Higher up, the moss forest holds fewer native mammal species than even the rainforest due to decreasing botanical diversity. Most species are arboreal. These include the tree kangaroos of genus Dendrolagus. Most notable are the distinct species of cuscus of genus Phalanger, the ring tails of genus Pseudocheirus, mosaic-tailed rats of the genus Melomys and hydromyline rodents, non-arboreal carnivores.
In the Alpine habitat, the vegetation is recent and is restricted mostly to scrub and grassland. Here we have the long-beaked echidna and Rattus richardsoni. Add two indigenous mammals, neither restricted to this zone: the long-tailed pygmy possum, Cercartetus caudatus (an arboreal omnivore) and the spiny rat Rattus rubber. Above 3300 meters, hunters and zoologists find that the bush wallaby Thylogale brunii may be very common, and, surprisingly, the Copper Ringtail Pseudocheirus cupreus has been seen often far from trees in alpine grasslands.
This alpine zone has seen great changes of vegetation during the recent past. During the last glaciation, the tree line dropped to around 2100 meters, then working its way to today’s 3900 meters, greatly expanding potential mammalian habitat. But thanks to the introduction of the sweet potato, which can grow to almost 3000 meters, Papuans have opened gardens in the upper montane forest and have greatly intensified their hunting in this zone.
Among the strangest beasts on our planet, monotremes or echidnas are egg-laying, but then suckle their young to qualify as mammals. To be a mammal, you must also have hair at some stage and be to maintain relatively constant high body temperature. Monotremes are warm-blooded but body temperatures are lower than other mammals, at 30 to 32 degrees Centigrade. Some readers might remember the duck-billed platypus from biology class. (But they don’t live in New Guinea, unfortunately.) These egg-laying mammals have extraordinarily large and complex brains with relatively high intelligence, unexpected in the world’s most reptile-like mammals. Monotremes are unknown from anywhere else in the world outside of Australia and New Guinea, even in fossil form. Their origins go back to at least the Jurassic era, some 160 million years ago. The montremes evolved exclusively in the southern portion of Gondwanaland. It is possible that they are derived from a stock of mammal-like reptiles which are different from the ones which led to both the marsupials and the placentals. They resemble reptiles in the structure of the eyes and some cranial bones. As in reptiles, the cloaca serves as a common chamber at the end of the reproductive and excretory systems, with a single opening to the outside.
There are only three species of montremes surviving today. The Duck-billed Platypus (Ornithorhynchus anatinus) is endemic only to Australia. There are two species of echidna, also called spiny anteaters. The Porcupine or Spiny Anteater (Tachyglossus aculeatus) is shared by Australia and New Guinea while the Long-Beaked Echidna (Zaglossus bruijni) - also an anteater - is a New Guinea endemic found only at high elevations. (Flannery, 1995) These are the only two montremes found outside Australia. The echidnas’ fur is intermixed with barbless spines. Their metabolism allows survival for a month with no food. As with the marsupials, monotremes lack a multifunctional bridge of nervous tissue called the corpus callosum which connects the two hemisphere of the brain in placentals. (Nowak, 1999)
Aside from the egg-laying monotremes, the world’s other mammals fall into two major categories, depending on the mother’s strategy of holding the embryo. In placental mammals, which make up the vast majority of this class, the embryo(s) are brought to term within the mother, inside her placenta. In marsupials, the fertilized eggs hatch in the oviducts and are retained for a brief period in the uterus. Then the tiny embryos emerge from the vagina and climb the mother’s fur into her pouch. Once there, they fasten on to one of her teats and hang on for dear life. But the embryos have no power to suck so the mother squirts milk into her offspring’s’ mouth by muscular action. The young are retained in the pouch until ready to face the world - with the option, for a while at least, to climb back into the pouch if danger threatens or for a nourishing drink. That is, until the pouch is already occupied by a new brood.
Marsupials began their existence about the same time as the ancestors of the much more numerous placentals: dogs, cats, deer, bats, humans and their ilk. No one has yet figured out (to our satisfaction) why placentals should be so widespread. Today, there is but a single marsupial species in North America, the Common or Virginian Opossum (Didelphis marsupialis) belonging to the family Didelphidae, the American opossums. While the same family has numerous species in South America, none are bigger than rats and they by no means dominate the mammalian fauna. There are no other marsupial families in the Americas and no marsupials anywhere else in the world. Except for Australia and New Guinea where the marsupials filled all ecological niches and have never lost their dominant role, in spite of the introduction of more ‘advanced’ placentals. With such a diversity it would seem that marsupials evolved in this area of Gondwanaland with a few members making it to South America before it drifted too far off to the east.
Montremes, marsupials, rodents and bats make up New Guinea’s indigenous mammals. Marsupials are soft, furry, cuddly (when young) and with the strangest of names. Only our Australian readers will be familiar with the common English names for most of the marsupials: quolls and dasyurids, bandicoots and wallabies. Readers from eastern Indonesia will know the cuscus. For Americans, only the possum will be familiar.
While there are nine marsupial families (and 60-odd species) in New Guinea according to at least some recent taxonomies, they can be more conveniently divided into four main groups: the possums (which include the relatively well known cuscus), the bandicoots, the dasyurids, with the tree kangaroos and wallabies making up the last general common classification.
Dasyurids have no good common group name in English, or any Western language. The name used comes directly from the scientific name of the family, Dasyuridae. This sound like a strange name to many, so laymen have tried to rectify by called them marsupial mice (or rats) and marsupial cats. Scientists throw up their hands in disgust and try to explain that these animals are completely different. Besides, they don’t even look like mice and even less than cats. But frames of reference are essential to humans. If you ever can get a close look at a dasyurid, notice that they have pointed snouts and lots of teeth (and they bite too!). All their toes are free, which might seem usual enough, except when compared to other marsupials: bandicoots, possums and wallabies have their second and third toes bound together, with only the claws separated. Dasyurids are ferocious fighters, picking at times on prey larger than themselves. But they mostly feed on insects, along with vertebrates such as frogs, lizards, small rodents and birds. The dasyurids are small to medium-sized marsupials, with the smallest at 95 mm. and weighing 5 grams to something over a half kilo. The now-extinct Tasmanian Devil weighed in at up to ten kilos. Males tend to die off in large numbers at the end of their first and only breeding season. This results from stress which inhibits their immune responses. Most dasyurids are terrestrial, with some arboreal species. They are usually active only at night. Many are endemic to New Guinea.
The dasyurids often superficially look like rodents, all with pointed snouts and a mouth filled with many teeth. Although they might resemble the placental rats, they are physiologically quite different. Their toes are all free while the other marsupials, the bandicoots, possums and wallabies’ second and third toes are bound together, with only the claws separated. The dasyurids fill the niches occupied by the placental shrews, weasels and the mongoose elsewhere. These carnivorous group are ferocious, taking on prey considerably larger than themselves. While all feed largely on insects, they also will tackle vertebrates such as frogs, lizards, rodents and birds. The genus Antechinus has yet to find a clever zoologist to give it an appropriate common name. The most common one, Antechinus melanurus nests below the crowns of various species of pandanus and feeds largely on spiders and beetles. In turn, owls are their chief predators. The Murexia genus feeds on moths and butterflies. The Aussies named some of these dasyurids of the genus Dasyurus as ‘quolls’ (these are the so-called marsupial cats) and they can’t be mistaken for other species due to their distinctive white-spotted coasts. In New Guinea, one species of quolls is restricted to the woodland savanna country between the Fly and the Digul Rivers, in the south-central part of the island. Another species can be found up to 3500 meters (Nowak, 1999)
Another group of mammals, the bandicoots (Family Peroryctidae) are unfamiliar to the rest of the world. Some may think that the name sounds familiar: it might be for readers of English novels set in India: there, bandicoot is a kind of large rodent, nothing to do with our marsupials. This is the so-called pig rat, Bandicota indica. Early Aussies (they were all Pommies back then) probably introduced the word, which caught on to such an extent that the Indian original has now to be qualified as the ‘bandicoot rat’. The name stuck to the Peroryctidae as the English colonists in Australia had no zoologists to scold them. It is now part of the Queen’s English. C’est la vie.
Our bandicoots thoughtfully show features which help humans distinguish them: two bound together inner clawed toes to distinguish them from the dasyurids and long, pointed snouts to prevent confusion with possums. The marsupial bandicoots of Australia and New Guinea are large as rats, with one, Mycroperoryctes murina weighing as much as five kilos. All the members of this group have the inner two toes of the hind foot bound together, thus distinguishing them from the dasyurids. Their long, pointed snouts set them apart from the possums. They are nocturnal, territorial and omnivorous. Insects, vertebrates and fruit are all included in their diet. The most widespread species, Peroryctes raffrayanus, becomes Raffray’s bandicoot to non-scientists. The spiny bandicoots include Echympera clara and E. kalabu, E. rufescens, and E. echinisita. It is tough to tell these four species apart as they are similar in size and appearance. The E. kelabu lives up to 1500 meters along with the E. rufescens in grasslands, woodlands and secondary bush as well as the rainforest.
The Order Diprotodontia groups the rest of our marsupials: the cuscuses, the various possums, pandemelons, wallabies and kangaroos. Many are found in eastern Indonesia and spread to the west as far as the Solomon Islands. This the largest and most diverse of marsupial orders, with extensive variation in size and shape. The two middle incisor teeth of the lower jaw are greatly enlarged and project forward. A second major unifier: 2nd and 3rd digits of the hind foot are joined by integumen - no other marsupial order is both diprotodont and syndactylous. They have a large neocortex and a superficial thymus gland. The order is predominantly herbivorous although some members may consume invertebrates and even small vertebrates. Smallest species weigh less than 15 grams, while the largest, Macropus rufus can reach 100 kg. The Diprotodon optatum, of the size and general appearance of a hippopotamus, has been extinct only 10,000 years. (Nowak, 1999)
The family Phalangeridae groups both cuscus genera found in New Guinea: Spilocuscus and Phalanger. All four limbs have five digits and all the digits except the first toe and the hind foot have strong claws; the first toe is clawless but opposable and provides for a firm grip on branches. The second and third digits of the hind foot are partly syndactylous, being united by skin at the top of the joint, but the nails are divided and serve as hair combs. The well-developed masupium opens to the front and there are 2 to 4 mammae. The entire plantar surface of the hind foot is covered by a large striated pad. The largest of them all, not found in New Guinea, is the Celebes Cuscus, Ailurops ursinus, 610 mm and to 10 kg. (Nowak, 1999)
The Phalanger and Spilocuscus genera of cuscus are the most wide-spread of Australasian marsupials, covering a zone from Sulawesi to the Solomons. Phalanger orientalis the common brown cuscus, occurs over most of this area and has seven subspecies. It feeds on a wide variety of fruit. Other cuscus species are more restricted in distribution. Cuscuses are medium-sized arboreal possums, easy to keep in captivity. Young animals become very tame and gentle, especially the Spilocuscus maculatus, found mainly in rainforests from Ambon and Seram to Kei and Aru, and on to New Guinea and Queensland. They are generally solitary and nocturnal. Their diet consists of leaves and bark of trees, lianas or ferns, orchids and other epiphytes, plus fruit. The males sport whitish fur with brown or black spots; females are white or pale on head and shoulders, posterior part of body brown or black. Pure white specimen are not uncommon. In the south coast, they have dark brown, grayish or almost black markings. Males grow to four kilos, surpassed in size only by the six-kilo (largest males) Sulawesi’s Ailurops ursinus. (Flannery, 1995) All cuscus live high up in forest canopy. Unfortunately for them, all cuscus are covered with valuable pelts and their fatty flesh is much appreciated by all Papuans.
The members of the Phalanger genus are mostly covered with thick, wooly fur. They are medium sized (325 to 600 mm and 1 to 5 kilos). Heavy and powerfully built, yellow-rimmed protruding eyes, bright yellow noses, inconspicuous ears, prehensile tail terminally covered with scales, lacking hair. Found mainly in tropical rain forest and thick scrub, they are arboreal with strongly prehensile tails, nocturnal, but sometimes descend to ground. They emit a penetrating musk odor, even if handled gently. Snarls and barks are produced when molested. They eat fruit and leaves, insects, small vertebrates, eggs. Breeding is continuous. Many of the island populations of P. orientalis introduced by humans in prehistoric times. (Nowak, 1999)
The possums of New Guinea are divided into three families, indicating differences unsuspected from the general common name. All are arboreal and several genera in the various families can glide from tree to tree, thanks to a limb-connecting membrane. The family Acrobatidae has but one member in New Guinea, Distoechurus pennatus. We do better with the family Petauridae, the gliding or striped possums. In the genus Petaurus we host two out of the five existing species, P. breviceps, the Sugar Glider and P. abidi. Some species have been recorded to glide up to 45 meters at night to catch moths. The record leaper is P. australis which can glide at least 114 meters and can change the vertical and lateral angle of its flight path in the air. The genus Dactylopsila, the Striped Possums, have four species, all found in New Guinea: D. trivirgata, D. tatei, D. megalura, and D. palpator. All are characterized by large first incisors and slender, elongated fourth digit with a hooked nail on the forefoot. They are nocturnal and arboreal, found in the rainforest and sclerophyll forest. An extremely unpleasant penetrating odor can emanate from some glands. This can’t be ejected as in skunks but the animals’ black and white markings and odor makes for a striking convergence with North American skunks. The family Pseudocheiridae, the Ring-tailed Possums, are closely related to the Petauridae members. We do well enough in this family, having five out of seven species in the genus Pseudochirulus and four out of five in the genus Pseudochirops. All told, there are six genera and 16 species in the family. (Nowak, 1999)
The family Macropodidae embraces pademelons, wallabies and all the kangaroos. In all these animals, the head is rather small in relation to body and the ears relatively large. The tail is usually long and thick at base, hairy, nonprehensile, used as a prop or additional leg as balancing organ when leaping and sometimes for thrust. In all except the genus Dendrolagus the hind limbs are markedly larger and stronger than forelimbs. Hind foot lengthened and narrowed in all genera, whence the name, ‘large foot’. Dentition for grazing or browsing, with the lower incisors very large and forward-projecting, a condition technically called diprotodont. All except the genus Dendrolagus moves by leaps and bound, using only hind limbs: this is the peak of development of jumping mode of progression. Being grazers or browsers, they have developed ruminant like bacterial digestion, enabling them to colonize nutritionally habitats unfavorable to most other large mammals. Food breakdown is aided by dense bacterial population in esophagus, stomach and upper portion of small intestine. (Nowak, 1999)
An unusual feature in the family, is called embryonic diapause. (This is the equivalent to delayed implantation found in some placentals.) Embryonic development can be stopped at about the 100 cell stage and resumed when conditions are favorable. This reproductive approach well adapted to the variable, often severe climate of inland Australia. Thus, reproduction becomes wonderfully well regulated according to the mother’s circumstances by this process. After copulation, the embryo begins to develop, but then this process stops in the uterus in a few days until hormones signal the time to continue the process. Thus a mother can keep three youngsters going, in various stages: an embryo stopped in the uterus, a joey in the pouch and a youngster out in the world but still suckling. Add to this the female’s ability to regulate the composition of her milk: high protein for the joey in the pouch, high fat for the youngster already hopping about but coming home for its meals. Once the joey in the pouch has developed enough to start a semi-independent existence outside but near the mother, the embryonic process restarts. But this does not last for long. Unlike placental mammals, the embryo is ‘born’ at a very early and undeveloped stage. At birth, even the largest kangaroos weigh only about one gram. They crawl into the pouch and stay there until ready to face the world.
There are six pandemelons, genus Thylogale, ranging from 1.8 to 12 kilos in weight Two of which two species are found in New Guinea: T. stimatica and T. brunii. The genus is distinguished by features of the incisor teeth and a comparatively short tail which is sparsely haired and thickly rounded. They live in the rainforest, dry savannah, sclerophyll forest and thick scrub and grasslands. Both are found starting at sea level, but the T. stigmatica stays in the lowlands while the T. bruinii reaches 4200 meters. Both are highly endangered by hunting. (Nowak, 1999)
Wallabies and tree kangaroos are the most visually unique members of the New Guinea mammalian fauna. They are set off from all other marsupials by three physiological factors: locomotion, reproduction and digestion. Long hind legs are meant for jumping, as with frogs, but with the advantage of a strong, elongated tail used for balance. The proportions and attachments of the hind limbs prevent casual strolling: they can now walk slowly. The digestive system finds its equivalent in placental ruminants such as cows: an enlarged stomach giving time for bacteria to break down vegetal matter by fermentation. In fact, swallowed food is sometimes regurgitated for ‘chewing the cud’. (Flannery, 1995)
The genus Macropus holds what most people think of as ‘normal’ kangaroos: the largest living marsupials. Some Red Kangaroos can reach 1.8 meters in height and weigh up to 100 kilos. Leaps of nine meters or more (13.5 meters is the record) and speeds of 48 kilometers per hour have been recorded. Kangaroos probably exceed the 19-odd million humans in Australia, the only place in the world with more large wild animals than people. There are 14 species of Macropus altogether, but we only have one of them in New Guinea: the M. agilis, the Agile Wallaby. The wallabies of this genus look like smaller versions of the large, Australian species. (Nowak, 1999)
There are two genera of forest wallabies, Dorcopsis (New Guinea Forest Wallabies) and Dorcopsulus (New Guinea Forest Mountain Wallabies). As the names indicate, these are from our island, with the first genus holding four species and the second with two species. They resemble tree kangaroos but can be told apart (if you know what to look for and can get a good look: not so easy...) by their broader heads, and less difference between fore and hind limbs. Their tails of the tree kangaroos are not as stiff as those of wallabies and they are used to balance, not so much as a prop. When alarmed, the tree kangaroos either make huge jumps out of the trees or descend hind end first, as humans. In this they are different from all other New Guinea mammals. (Flannery, 1996)
Tree kangaroos are a New Guinea specialty, with 8 species (and 7 more subspecies) of the group (genus Dendrolagus) found on the island and two in Australia. A fascinating book (Flannery, 1996) with excellent painted illustrations deserves a good look by anyone interested in New Guinea’s unique and most spectacular mammals.
For being secretive and mostly nocturnal animals, trees kangaroos were found and scientifically described very early in the written story of New Guinea’s biodiversity while the last one was given its Latin name only in the mid-1990s. The first specimens were collected by Salomon Muller and Heinrich Macklot in 1828 in the Lobo district (Triton Bay) and described in 1836 by Coenraad Temminck, the first director of the excellent Rijksmuseum in Leiden, Holland. Based on the collectors’ notes Temminck called his tree kangaroo Dendrolagus, still the accepted genus name. The name, derived from Greek, means ‘tree hare’ so called for its culinary qualities, with a distinctive and delicious gamey flavor. The two earliest species were D. inustus and D. ursinus. The two collectors also reported the animals making great pets, but this must be taken with caution as the cuddly qualities depend on the species, age, age of capture and sex as temperaments vary enormously. Jarred Diamond, the famous science writer and ornithologist, observed the tree kangaroo D. goodfellowi in the Foja and Gautier mountains of Irian Jaya, where he found them common, diurnal and unconcerned by his presence, allowing approaches to as close as 10 meters. However, no Papuans live or hunt in these mountains, deserted of humans, whence the lack of fear of man. (Flannery, 1996)
Most larger mammals with a pleasant disposition toward man end up in the pot, especially in New Guinea. As with many other animals, the use of dogs and firearms in PNG has had devastating effects on tree kangaroos. In Irian most hunting is done with dogs, bows and arrows, so the animals have had somewhat better prospects for survival. And there are taboos which gives the tree kangaroos a measure of protection. This is also true in Australia where the aborigines held mountain tops as forbidden areas, the dwelling place of ancestral spirits and thus a refuge for all animals, including the two species of tree kangaroo found outside New Guinea. There is also a curious association between some Papuans and tree kangaroos. The Swiss art collector Paul Wirtz, who joined the 1921-1922 Kremer Expedition to Irian’s central highlands, reported on this. In the Swart Valley, near Bokondini, he found out that the Dani classified humans and everything else in the universe into two classes: waya and wenda, possums and tree kangaroos. (Flannery, 1996) A bit further to the west, some clans of the Moni ethnic group hold an endemic species, Dendrolagus mbaiso in special esteem as an ancestor. (more on the respect for this species in the second section of this book)
All kangaroos evolved from an arboreal ancestor which resembled an possum and had an opposable big toe (hallux) of great advantage for an arboreal life-style. All kangaroos adapted first to a terrestrial existence, then the tree kangaroos did what they had to do in order to get back in the trees. And then, quite recently, one of the species, the D. mbaiso, has been re-adapting itself to a largely terrestrial existence. All these changes of habitat required major evolutionary adaptations of limbs and some organs.
The first major set of changes adapted all the kangaroos to terrestrial life, losing their prehensile tail and the opposable use of the hallux (innermost digit of the hind limb, the big toe). Hopping became the most efficient way to move around and this meant strong, stiff ankles which could not twist sideways. Their new diet also evolved from browsing to gazing, requiring digestive adaptation. When some of the terrestrial species decided to return to living in the trees these adaptations became a hindrance and they had to try to re-acquire arboreal adaptations. This was facilitated by Dollo’s law: ‘in evolutionary terms, it is much less difficult to re-acquire a lost feature than evolve a new one’. (Flannery, 1996).
Tree kangaroos evolved from an ancestor resembling a kind of kangaroo, called rock-wallaby, at least five million years ago. Flannery speculates that predators forced these rock wallabies to rocky places with little soil and stunted rain forest trees. The rough terrain put a premium on the ability to leap downwards and some tree kangaroos today can jump down from their branch perches 20 meters or more and get away uninjured. The ancestral tree kangaroos at first also learned to climb sloping trees to get away from predators. The tree climbing business puts a survival premium, and thus nudges evolution in favor of the animals with the strongest forelimbs, wrist and ankle mobility and the toughest curved claws. But even more important than this, survival chances favored those proto-tree kangaroos who could undo millions of years of evolution which had resulted in unmoveable hind limbs. Thus we have these recently hopping terrestrials slowly developing hind limbs which could face each other to facilitate the grasping of tree trunks for climbing. As far as the size of the hind feet are concerned, evolution has produced two groups. The long footed group is made up of the D. bennettianus, lumholzi and inustus species (only the last one is found in New Guinea) while the rest are the long-footed group. In this particular adaptation, the short-footed group had the advantage, as they could maneuver more easily along narrow branches. The long-footed group tends to move by hopping and are less efficient in moving about trees. They can walk but do so less than the short-foot species. The ability to move the hind limbs independently was lost when kangaroos learned to hop and only with the tree kangaroos has this ability re-evolved.
The diet leaves, twigs and young shoots up in the trees required a reversal in the evolutionary adaptation browsing of the digestive system which was equipped to handle grasses. Thus the tree kangaroos had to develop a gut for gazing, a specialty of the long-footed species. Thus they developed a specialized stomach with a larger caecum (the pouch at the beginning of the small intestine) which was more efficient for digesting leaves. Another adaptation to the leaf-eating life style led to long pre-molars, but the tree kangaroos are not special in this feature: many other lineages acquired these longer teeth independently through a process called convergent evolution. (Flannery, 1996) The first and best known of the results of convergent evolution has led to similar limbs in many kinds of animals, all descendant from the first four-limbed (tetrapod) ancestors. Similar bodies of the marsupial and mammalian wolf are another example.
Leaf eating adaptation has a price in the form of a general sluggishness. The leaves, mostly with low nutritional value, have evolved strong chemical defenses against browsers, so animals eating them have to limit their food intake and have very low basal metabolism rates. Thus tree kangaroos are rarely very active, breed slowly and have the longest pregnancies and periods of juvenile dependency of any marsupial. (Flannery, 1996).
Tree kangaroos made their way north from Australia to New Guinea two to four million years ago, but there were few other kangaroos in the migration: forest wallabies, now extinct giant wallabies and some pademelons. The tree kangaroos found an ideal home to speciate in New Guinea. Due to their preference for mountain forests, various populations became isolated due to climate and land form changes. While Australia only has two species, there are eight in New Guinea, along with seven sub-species. Some of these sub-species populations are currently evolving into full species as fragmented habitats such as mountain tops encourage divergence (Flannery, 1996) by preventing genetic back-crossing with parent groups.
Man represents one of the factors responsible for this mountain-top isolation as these areas are less subject to hunting pressures. Humans, who have been present for tens of thousand of years in New Guinea might well also have influenced the evolution of tree kangaroos. By killing the larger individuals, the evolution favors smaller, faster maturing animals. Giant tree kangaroos as well as giant wallabies have become extinct on New Guinea, perhaps due to man’s hunting habits. Man perhaps also influence the coloration of the tree kangaroos as well as their behavior, driving many of them to nocturnal or crepuscular life-styles. Coloration might have been influenced as well, favoring hues which blend in with the trees.
Man is not the only threat to the tree kangaroos. There have been documented cases of pythons killing and consuming tree kangaroos in Australia (the Amethystine Python) and this undoubtedly also occurs in New Guinea. Larger marsupial predators, now extinct, may well have preyed on tree kangaroos as well, replaced today by dogs. Other potential tree kangaroo-eaters include the New Guinea Harpy Eagle, Harpyopsis novaeguinea (for young ones) and crocodiles (for any size). On the other end of the scale, the tree kangaroos are blessed with a fur coat which lacks an under-fur, the favorite habitat of small parasites. But they are subject to strains of avian tuberculosis. (Flannery, 1996).
Behaviorally, there are great differences between the various species of tree kangaroos. Flannery report on the threat posture or superiority display of two of them, D. notatus and D. mbaiso. There is a high-pitched whistle accompanied by raised arms while sitting on hind limbs with claws stretched and the tip of the snout raised and in a bite threat. Often in this mode the tail thrashes about. Male kangaroos engage in bouts of boxing, wrestling and fierce biting for territorial dominance which leads to harems of varying sizes. The most sociable of them, the D. dorianus dorianus, establishes his dominance then allows other males around who, however, do not challenge his alpha male role during courtship and copulation. Tree kangaroos in general have the longest gestation period and maternal care of any marsupials, albeit with much variation between species. The gestation varies from 45 to 54 days, after which the joey spends eight to ten months in the pouch. The young often return to the pouch after a period of exploration and some keep coming back for as long as 15 months after birth. Many of the young accompany the mother for two years, retaining juvenile face coloration perhaps thus preventing fights with older males. Tree kangaroos are among the most spectacularly colored of all mammals and live to about 20 years of age.
Evolution has also adapted the bodies of forest wallabies to an arboreal existence with less difference between front and hind limbs and a more floppy tail used as a balance rather than as a prop for their terrestrial cousins. As with the cuscus and the tree ‘roos, wallabies are overhunted as the Papuans place high value on the animals’ fur and tails, aside from the flesh and attempts to take live ones. The wallabies are closely related to the tree kangaroos, being members of the same family. Both groups have retained canine teeth and have relatively short hind limbs. These wallabies are unique to New Guinea, with Australia retaining only fossils from the group now extinct there. The forest wallabies are active at dawn and dusk by nature but will switch to night-life if intensely hunted. The two genera of the group, Dorcopsis and Dorcopsulus both feed on a wide variety of plants and fruit. The wide-spread Dorcopsis muelleri the Western Forest Wallaby, ranges from the lowlands of the southwest to the Digul River area in the east, to the Rouffaer and Mamberamo lowland forest in the north and in the west to the Raja Ampat Islands off the Bird’s Head.
1. Family Dasyuridae
With the absence of placental mammals, some marsupials developed into forms resembling the placentals taking over the ecological niche these placentals would inhabit. This family includes the marsupial ‘mice’ (Antechinus, Murexia) and the marsupial ‘cat’ (Dasyurus albopunctatus) the largest surviving carnivore in New Guinea, ranging in habitat from sea level to 3500m. The largest males weigh in at just over 700 grams. Perhaps the D. spartacus is larger but no weight has been established for this animal. Members of this family show a high degree of endemism.
2. Family Peramelidae
This family includes only a unique bandicoot, a single species: Isoodon macrourus which is widespread and common in Northern Australia and southern New Guinea.
3. Family Peroryctidae
These are the common rainforest bandicoots.
4. Family Phalangeridae
The family of the well known and common cuscus which is ecologically similar to the placental New World sloths or Old World slow lories.
5. Family Burramyidae
A single pygmy possum species makes up the whole family: Cercartetus caudatus.
6. Family Petauridae
These are the striped and gliding possums, also known as ‘ringtails’. Here we have the Petaurus beviceps, Sugar Glider, ecologically similar to various ‘flying’ squirrels’ of the Rodentia Order.
7. Family Macropodidae
Most wallabies and tree kangaroos are grouped here, including the majority of the larger browsing and grazing mammals of this area. The tree-kangaroos are highly arboreal and unique to the New Guinea ( except for two species in Australia), living in the gallery forest and savannah of Trans-Fly plains.
All tree kangaroo belong to the genus Dendrolagus, with the following species (subspecies in parenthesis): D. inustus (inustus finschi), D. ursinus, D. goodfellowi (goodfellowi buergerse, goodfellowi pulcherrimus), D. marschiei, D. spadix, D. dorianus (dorianus mayeri, dorianus notatus, dorianus stellarum), D. scottae (with an undetermined subspecies), D. mbaiso.
8. Family Acrobatidae
This is a recently established family with only two species, one Australian and the other found in New Guinea: Distoechurus pennatus.
9. Family Pseudocheiridae
Up to a recent revision of marsupial families, the members of this group belonged to the same family as petaurids and burryamids.
Bats exceed all other mammals in species numbers except for rodents. Bats are scientifically called chriopterans, derived from the Greek words meaning hand and wing. The bats’ wings are thin sheets of membrane, very different from the feathers on birds. The pterodacyls or flying reptiles had wings similar to those of contemporary bats. It is probable that bats are monophyletic and all descend from a single ancestor. Powered flight evolved but once in mammals. From their teeth, scientists can reasonably guess at an insectivorous ancestor. Bats evolved to their current forms during the Eocene Period some 50 million years ago. Their teeth, used as the base for classification, reflect their diet: fruit-feeders, insect feeders and blood suckers. Bats are also divided by the sense used to move around and locate food: sight or echolocation. The latter sense uses ultrasonic sound which are emitted by the bat, bounces off objects or prey and returns to the animal for navigational guidance, similar to radar.
All bats belong to the Order Chiroptera. There are two suborders: the Megachiroptera (with a single family, the Pteropodidae) and the Microchiroptera (with lots of families). Unfortunately the prefixes mega- and micro- are not always accurate as some of the Megachiroptera are smaller than several of the Microchiroptera. There are 977 (another count has 986) species of bats in the world, grouped into 192 genera and 18 families. Head and body length ranges from 25 to 406 mm.
Many species have a nose leaf or other facial ornamentation through which echolocation sounds are emitted and augmented while the external ears of bats are remarkably modified with folds and crenulations that may aid in sound reception. For many kinds of bats vision may be less significant than hearing and olfaction. Like those of many nocturnal animals, the retina of bats consists almost entirely of red cells and lack the cones associated with color vision. However, most megachiroptera have large eyes and are capable of color vision. Echolocation used by more than half of the species of bats for nocturnal orientation and prey capture. Of the megachiroptera, only the genus Rousettus has echolocation capabilities. Bats need more water and moist foods than comparably sized mammals of equal weight as their wings have such great evaporation surface in comparison with their weight. Bats destroy many harmful insects and pollinate many flowers. The guano deposits in caves are used as a valuable fertilizer. People eat the larger ones. Bats produce one young per year. They live longer than mammals of comparable size, to 30 years. Most authorities believe that bats and gliding lemurs evolved from insectivorous, probably arboreal ancestors. (Nowak, 1999)
Bats can be divided into six groups, according to their principal feeding habits:
4. true vampires
5. carnivorous (small mammals, birds, lizards and frogs)
There are 91 species of bats in PNG, nine per cent of the world total. Seven of the 18 bat families are also found in PNG, with both suborders present. (No similar figures are available for Irian Jaya.) Seventy of PNG’s species are shared with surrounding countries and 19 species endemic for 21% of the total, but some shared with Irian Jaya. Indonesia has 38 species in common with PNG, a bit more than Australia, with 30 and the Solomons with 28. Some 80 per cent of the island’s species are found under 500 meters’ elevation. While there are over 700 resident bird species, with much fewer bats holding permanent citizenship. However, no bird species reaches the local density of bats, where over 100,000 may be roosting together in caves.
The mega-bats, when raised by humans can easily become pets, just like cats and dogs. The larger Megachiroptera bats are fruit eaters while all 55 microbats are primarily hunters of arthropods. Some bats specialize in a diet of fruit, nectar and pollen, flower blossoms or a combination of these, along with insects. The Greater Flying Fox, Pteropus neohibernicus, can attain a wingspan of 1.6 meters and is one of the three largest bats in the world. Along with some of the world’s largest bats, New Guinea also hosts one of the smallest, the Lesser Sheath-tailed Bat, Mosia nigrescens, weighing in at 2.5 grams. The weight of most of the species in New Guinea range from six to 50 grams.
Family Pteropodidae: Old World Fruit Bats, Bare-backed Bats, Roussettes and Flying Foxes. There are at least 20 species on the island. out of a world-wide total of 169 which range from 15 grams for the smallest nectar and pollen eaters to over 1.5 kg. for the largest fruit eaters, often hunted and eaten by humans. These bats forage by exclusively by sight and smell, except for the members of the genus Rousettus which emits ultrasound in addition to using its eyes. Most are active in the evening and at night.
In the genus Rousettus, the Rousette Fruit Bats, we have but one species (out of a total of nine) in New Guinea, the R. ampexicaudatus, a wide-ranging animal, found from Burma to the Solomons. Night-time foraging round-trips can cover as much as 50 kilometers. Its habitat includes the lowlands as well as the mountains, spending the daylight hours mostly in caves.
We have five species of the genus Pteropus, the Flying Foxes, the most numerous in this family, with some 60 species. The New Guinea species are: P. alecto (from Sulawesi to northeast Australia), P. conspicillatus (Halmahera to northeast Queensland), P. neohibernicus (also on nearby islands), P. macrotis (Aru as well)and P. scapulatus (extreme southern New Guinea and north-east Australia). They are found in forests and swamps, often on small islands near coasts with most of them roosting in emergent trees that rise above the forest canopy. They are strongly colonial, few dozen to a few hundred thousand, not long ago millions. Their foraging areas are well removed from the roosts. Populations on large land masses may travel 40 to 60 . to reach a feeding area. They are mostly nocturnal. During daylight there is much noise and motion in roosts. The principal food is fruit juices, eaten by squeezing pulp into the mouth, swallowing the juice and spit out seeds and pulp. They may swallow the pulp if very soft, like bananas. These bats also chew eucalyptus and probably other flowers for juice and pollen. Some drink sea water for mineral salts. Births highly synchronized and seasonal for most species. They play an important role, especially in the Pacific islands, in pollination and seed dispersal for a great variety of plants used for lumber, food and medicine but are considered pests by fruit growers. Over half of the species are classified as threatened by the IUNC, more than any other mammal. This is due to humans’ fondness for its flesh. The French in New Caledonia make a pate out of the meat and locals everywhere feast on its flesh. In wealthy Guam they are imported and sold for as much as $40 per bat. Just about all the local flying foxes there have been exterminated by the aggressive and imported Brown Tree Snake, Boiga irregularis.
The genus Aproteles, with but a single species, A. bulmerae, has a fascinating story. It was studied and described in the 1970s by James Menzies, as Pleistocene fossil, thought to be extinct for some 10,000 years. However, Tim Flannery and Lester Seri being found live specimen in 1975. Unfortunately, this group of bats did not last long: after the world of their discovery spread, the roost was wiped out by native hunters. A real tragedy for the world’s biodiversity. But the story has a happy ending. 17 years later another population found, followed by reports of one more. it looks like the species just might survive, if the Papuan hunters can respect their existence. The colony had been traditionally protected by the local Papuans of the area, but outsiders with caving equipment and guns can quickly wipe out any bat colony.
Genus Dobsonia: Bare-backed Fruit Bats: with 14 species - we have D. magna, D. emersa, D. beauforti, and D. praedatrix (in the Bismarck Archipelago). There is considerable variation in color but most species are dull brown washed with olive, grayish black. Unlike most other pteropodids, Dobsonia prefer caves and tunnels rather than trees for roosting; D. magna is abundant in NG at 2700 m., in the twilight zones of caves. It sometimes forms immense colonies, with many thousands of bats per cave.
Two genera of Pteripodidae have laterally-opening tubular nostrils, along with large, well-developed eyes: Nyctemene and Paranyctimene. The genus Nyctemene, the Tube-nosed Bats, holds 13 species. N. draconilla, N. cyclotis, N. certans, N. aello, N. ceaeno, N. major, are all endemics to New Guinea and nearby islands. N. albiventer is found on Halmahera, New Guinea and islands nearby, Banda, Aru, and the Bismarck Archipelago. Usually the species are dark brown spinal stripe, with the wings, forearms, and ear membranes speckled with yellow. The mottled and broken color increases chances for concealment. N. aello inhabits the primary and secondary rainforest and swamp forest; N. albiventer, also lives in the primary, secondary rain forest, but primarily in mountain forest, sago swamp, and in the vicinity of native gardens. N. cyclotis holds to the primary rain forest, from sea level to 1650 m. Captives prefer soft, juicy fruit and won’t take insects. The genus Parancytimene, the Lesser Tube-nosed Bat has but a single species, P. raptor, found in PNG. Both genera live mainly on pollen and nectar, with the Nyctimene including insects in its diet.
The genus Macroglossus, the Long-tongued Fruit Bats, has two species. We only have representatives of the wide-ranging M. minimus which is found from south Thailand to New Guinea and on to north Australia. They eat pollen of a wide variety of plants, especially wild and cultivated bananas, coconuts and mangroves. Like many of the smaller fruit bats, usually solitary, reducing chances of discovery. The genus Synconycteris, the Blossom Bats, holds three species. One species spreads from Buru to New South Wales. The S. hobbit is endemic to from west-central to eastern New Guinea. As others of subfamily Macroglossinae, the tongue is slender, long and protrusible with brushlike projections that pick up nectar and pollen. S. australis is found in a variety of habitats covering almost all forest and woodland formations in PNG, from sea level to 2860m. It is specialized in feeding on nectar and pollen.
Suborder Microchiroptera: insect eating bats, foraging by echolocation.
Family Emballonuridae: Sheath-tailed Bats (also called Sac-winged Bats and Ghost Bats): 13 genera and 49 species, in total. The members of this family have nose leaf so they show a smooth face and lips; the ears are often united across top of head. Glands in the wings secrete a red substance with a strong odor. The common appellation of sheath tail comes from the nature of tail attachment, where the appendage pierces the tail membrane and its tip appears completely free on the upper surface of the membrane with the base of the tail being loosely enclosed in this membrane. Thus, in flight, the tail membrane can be lengthened by stretching the hind limbs: it then slipping quite easily over the tail vertebrae. Thus, by pulling in their hind legs or in moving them out, these bats can ‘set sail’. Most forms can steer and turn exceptionally well.
The genus Saccolaimus, with five species, has two representative on our island: S. flaviventris, found in south-east PNG and throughout Australia, and the S. mixtus, in south and east New Guinea and the Cape York Peninsula. The Genus Mosia, Lesser Sheath-tailed Bats, has but one species, M. nigriscens, ranging from Sulawesi through much of New Guinea, in secondary forests, freshwater mangroves and in the vicinity of villages. It roots under leaves, in roofs of huts as well as in caves. This bat often flies before dusk it the highest levels of the rainforest as well as around dwellings and gardens. The genus Emballonura, with nine species, goes under the common name of Old World Sheath-tailed Bats. Five species fly around New Guinea: E. raffrayana (Halmahera to Solomons), E. beccarii (also in nearby islands, including Kei), E. dianae (PNG, nearby and the Solomons), E. furax (only in south-west and south-east New Guinea), and E. serii (New Ireland and Bismarcks). The main diet is insects but fruit is also occasionally eaten.
Zoologists are uncertain as to the existence of any members of the family Megadermatidae in New Guinea. These are commonly called the False Vampire Bats or the Yellow-winged Bat. As the family spreads from south-east Asia through Indonesia and on to Australia, there should be some species in New Guinea, although there have been no confirmed sightings yet due to secretive habits. There should be at least one species of the genus Macroderma in New Guinea. We know its habits from studies elsewhere: they hang from tree at 3 m. and watch for prey. It commonly takes house mice, but also native rodents, small marsupials, other bats, birds, reptiles and insects. Roosts alone or in small numbers. This is the largest member of its suborder.
The family Rhinolophidae is commonly referred to as Horseshoe Bats. There is but a single genus, with 12 species, of which four are denizens of New Guinea. The most common one in new Guinea is R. euryotis which ranges from Sulawesi, Bismarcks, Aru and New Guinea. The genus probably originated in south-east Asia. They have a peculiar, complex, nose-leaf expansion of the skin surrounding the nostrils with the lower part horseshoe-shaped. These bats generally fly with their mouth closed and emit ultrasonic sounds through the nostrils. Sound may be oriented with the aid of the nose leaf. The field of vision is probably of little importance, partly obscured by nose leaf. They have a fluttering, butterfly-like or hovering flight. Found in a great variety of forested and non forested habitats, at both high and low altitudes.
The family Hipposideridae, the Old World Leaf-nosed Bats, hold 9 genera with 69 species. They are different from Rhinolophidae by features of the nose leaf and ear, characters of the teeth and greater posterior width of the skull. Many species have a sac behind the nose leaf that can be everted at will, with a waxy substance, chiefly in males. They roosts in hollow trees, caves, buildings. They fly lower than most and catch in flight insects such as beetles, termites, cockroaches, cicadas. Echolocation takes place via the nose, specialized for short-range hunting. There are two genera in New Guinea. One of these, Aselliscus, or Tate’s Trident-nosed Bats, has two species, one of which lives in New Guinea: A. tricuspidatus, ranging from the Moluccas to New Guinea and into the Pacific as far as Vanuatu. The other genus, Hipposideros, holds seven genera and 57 species. Nine of these are found in New Guinea: H. ater (from India to Australia), H. calcaratus (also nearby islands, including the Solomons), H. maggietaylorae: (and nearby islands), H. carvinus (from the Malay Peninsula through New Guinea and to Queensland), H. muscinus: (south New Guinea only), H. wollastoni (west and central New Guinea only), H. corynophyllus (central and possibly east New Guinea only), H. edwardshili (north and central New Guinea only), H. diadema (from Burma to Queensland).
In the Vespertilionidae family, the Long-eared Bats, there are 43 genera and 342 species world wide, in both temperate as well as tropical zones. Out of these, New Guinea inhabitants include eight or ten genera (my sources disagree) and 21 (or 23) species. Some other common names for members of this family include wattled, large-footed, pipistrelle, broad-nosed, murine, small-toothed, wooly, big eared and bent-wing bats. Some species in this family have ears almost as long as their body. The genus Myotis has the widest distribution of any genus of bats. Most send out ultrasonic sound via the mouth. Nose leaf is lacking in all but two genera. The eyes minutely small but the ears are as long as 40 mm. Range in altitude from sea level to the limits of tree growth and from tropical forests to arid areas. Most are cave dwellers, also living in mine shafts, tunnels, rock crevices, buildings, tree hollows, foliage of trees and bushes, hollow joints of bamboo, large tropical flowers and under loose bark. Nearly all feed on insects, generally captured in flight. One unusual species, Myotis vivesi, definite eats fish, and two other species of Myotis suspected of same crime.
The genus Pipistrellus, the Pipistrelles, has five kinds of bats in New Guinea out of a total of 68 species. Over most of their range, they are the first to appear in evening, some even occasionally flying in bright sunlight. The early appearance and jerky, erratic flight are characteristic. The species are as follows: P. tenuis (also in the Louisiades), P. collinus (only found in the central highlands of New Guinea), P. angulatus (also in nearby islands and the Solomons), P. papuanus (south Moluccas through New Guinea and on into the Louisiades), P. wattsi (only in south-east PNG and nearby Samari Island). The genus Chalinolobus the White-lipped or Groove-lipped or Wattled Bat has but one out of its six species in New Guinea, C. nigrogriseus, found in PNG and north-east Queensland. We also have but one out of the four species of the genus Scotorepens, the Lesser Broad-nosed Bats. This is S. sanborni, found from Timor to PNG and Queensland. We have five out of the 11 species of the genus Miniopterus, Long-winged or Bent-winged Bats. The species are: M. schreibersi, M. magnater, M. medius, M. pusillus and M. tritis. All have wide distribution outside New Guinea, with the M. schreibersi ranging from southern Europe to Japan to, New Guinea, Australia and the Solomon Islands. All the species in this genus are highly gregarious, appear in the early evening with a rapid, jerky flight to feed mostly on small beetles.
The Tube-nosed Insectivorous Bats, genus Murina, are split into 14 species, all uglies except to the zoologists specializing in them - and perhaps their mothers. We only hold the M. florium which ranges from Sulawesi to north-east Queensland, via New Guinea. It is low-flying, skimming surface crops and grass in feeding flights. It is thought to be the rarest of bats in Australia. The genus Kerivoula, Painted or Wooly Bats, have four species in New Guinea out of 22. Two are endemic: K. muscina and K. agnella. The other two, K. myrella and K. papuensis are found only in close by New Guinea. In the genus Nyctophilus, the New Guinea Bats or the Australian Big-eared Bats, we have two endemics, N. microtis and N. microdon. The other two are shared with Australia: N. bifax and N. timorensis. They live in forested areas, scrub country and arid regions in small caves, crevices, tree hollows, under bark. Most show a slow, fluttering but highly maneuverable flight, pursuing a variety of insects in open air as well as gleaning them from foliage and tree branches. The last genus of the family found in New Guinea, Pharotis, has but a single species, anywhere: P. imogene. These might now be extinct: around 1890 some 45 specimen were collected at sea level in the far south-east corner of New Guinea and they have not been spotted since then.
The family Molossidae, the Free-tailed or Mastiff bats are divided into 16 genera and 86 species, all in the warmer parts of the planet. Head and body length range from 40 to 130 mm. The tail projects far beyond the free edge of the narrow tail membrane, whence one of the common names. The head is rather thick and the muzzle is broad. Eyes are small, the ears thick and leathery, variable in size and form and often united across the forehead and directed forward. The nostrils are usually open on a pad the surface of which is often adorned with small hornlike projections. There is no nose leaf. The wings are long, narrow, thick and leathery. They roost in caves, tunnels, buildings, hollow trees, decayed wood of old logs, crevices of rock cliffs and holes in earth. Some aggregations have individuals counted in millions, some prefer smaller groups, while some are solitary. Compared to other insectivorous bats, their flight is swift and relatively straight. They fly with open mouths, sending out ultrasound. Diet is of insects, often hard-shelled. There was an attempt to use them to carry small incendiary during W.W.II but the project was abandonned.
The genus Mormopterus, Little Goblin Bats, has 10 species, of which two are in New Guinea and nearby areas: M. loriae and M. beccarii. They inhabit tropical forests, woodlands, open areas, and cities, roosting mainly in roofs and tree hollows. These bats usually forage for insects above tree canopy, water holes, and creeks but sometimes scurry after prey on the ground. Their flight is swift and direct. The genus Tadarida, Free-tailed Bats, has but one species in New Guinea out of a total of the eight: T. kuboriensis, an endemic. The genus Chaerephon, Lesser Mastiff Bats, hold 14 species including the only representative in New Guinea, C. jobiensis found from Seram to Tonga. The genus Otomops, Big-eared Free-tailed Bats are split into three widely scattered species ranging from Africa to New Guinea. O. papuensis and O. secundus are New Guinea endemics. They roost in caves, hollow trees and human-made structures.
The rodents’ name comes from the Latin, meaning to gnaw. The repeated biting which characterizes the group is based on two sets of long incisors, one in each jaw and projecting at the front of the mouth. These incisor teeth grow constantly throughout life and must be worn down continually. If the wear stops, the lower incisors grow out of the mouth and into the eye, causing death. In addition to dental characters, rodents have other anatomical features in common. The bones of the lower arm, the radius and the ulna, are distinct and the elbow joint allows free motion of the forearm. The hand usually has five fingers, though the thumb may be vestigial or absent. The toes number from three to five. The stomach is variable, ranging from a simple sac to a complex, ruminant like organ, as in the lemmings.
While rodents include some quite large animals such as porcupines and beavers, most tend to a more modest or small size. The animals are very active and have a relatively large surface area as compared to bulk or volume. This means that there is a great deal of heat loss which must be replaced by energy from food. Thus their insatiable feeding. The 2000-odd species of rodents have adapted to the most varied habitats. Their classification is based on anatomical details, especially the tibia and fibula leg bones.
The 2052 species of rodents described so far, by far the most of any mammalian order, fall into 29 families and 468 genera. They have traditionally been divided into three suborders based largely on jaw musculature and associated structures of the skull:
1. Sciuromorpha (squirrel-like rodents)
2. Myomorpha (mouselike rodents)
3. Hystricomorpha (porcupine-like rodents)
Now, only this has been reduced to two, the Sciurognathi and the Hystricognathi, distinguished primarily by mandibular structure. The lower hierarchies are based mainly on jaw anatomy and dentition.
Rodentia the only surface-dwelling placental mammals to have naturally colonized Australia and NG. All rodents in the Australia-New Guinea area belong to the Muridae family which has radiated extensively, especially in the arid areas of Australia. In New Guinea, their extensive spread and speciation has resulted in many endemic genera and species, almost off of which are specialized for life in the moist upland forests. New Guinea’s murid fauna is abundant and diverse, one of the most species-rich areas anywhere in the world.
The Muridae, with 301 genera, 1336 species are by far the largest mammalian family. They are found everywhere except parts of the West Indies, New Zealand, some oceanic islands and Antarctica. There are 16 sub-families. In our sphere, we have just two:
1. Subfamily Hydromyinae, the Water Rats. They are shrew-like or muskrat-like found in parts of the Australian-Oriental region and characterized chiefly by a reduction in dentition. These are highly specialized animals with large webbed feet, small forefeet, vestigial ears and a tail fringed with hairs for use in swimming. There are thirteen genera and many species, ranging from the Philippines to New Guinea and Australia.
2. Subfamily Murinae are generalized Old World Rats and Mice. Most live less than two years in the wild. Population peaks then crash due to less food supplies, usually cyclical, lasting three to four years. These are the blokes that carry the plague. Rats are next to insects as carriers of human diseases. Fortunately, they have some very efficient predators in the from of snakes, owls and hawks. Their arrival in Australia, New Guinea and Madagascar was not long ago, during the Pleistocene to Recent times.
The rats and mice of the Murinae subfamily have 16 teeth, with no premolars. The tail is always thin and covered only by fine hairs or scales. As they will eat just about anything (where is my soap?), rats and mice are well suited to live in a commensal relationship with man: his garbage is their feast. And they breed ‘like rabbits’: under ideal conditions, it is theoretically possible for a pair of rats to procreate 20 million progeny in just three years. Thank God for predators!
The genus Rattus, surprisingly, has only 56 species. We are cursed with a fair number of them, some 13 species in New Guinea, some of recent introduction by guess whom. In numbers of species as well as individuals, Rattus is the largest mammal genus; it was even bigger not too long ago but now some of them have been shifted to other genera.
According to my Bible of mammals (Nowak, 1999), there are 13 species of the genus Rattus in New Guinea. Out of these, four are wide-spread, seven are endemic to New Guinea and nearby islands and two are shared with Australia. The R. tanezumi, found in western New Guinea and many Pacific islands seems to keep the elsewhere ubiquitous R. rattus away. No such luck with the tough R. norvegicus, the Norway or Brown Rat which can weight up to a half kilo (but usually not so huge: 200 to 400 g. but still with a mean bite) and found just about everywhere. This is the sewer and garbage rat, a burrower. Rats are generally omnivorous, eating all people consume plus other delicious items like soap, hides, paper, beeswax and even babies. It does not need too much of a pretext to attack humans, but, like just about all animals, it does need a reason. This species, plus the almost equally awful R. rattus like to live around people (especially those that leave garbage around at night) and have a devastating effect on native birds, reptiles and the vegetation. The R. rattus is an extremely agile climber and prefers upper levels, scurrying about at night while making a racket. R. rattus is by far the more common and widespread in the tropics, while R. norvegicus is more adaptable to temperate zones, especially to urban areas, but we do have more than enough of them in New Guinea, especially in ports.
We add R. exulans, the Polynesian Rat, to the cosmopolitan species scurrying about New Guinea, along with R. argentifer, the rice-field rat whose range encompasses southern Thailand to New Guinea. Two species, R. leucopus and R. sordidus are shared with Australia. The indigenous species are: R. movaeguinea, R. steini, R. jobiensis, R. steini, R. giluwenis, R. praetor (also found in the Bismarcks and the Solomons) and R. sanila. The last species has been only found as a 3000 year old fossil in the Bismarck Archipelago, but zoologists think it could still be alive and well, but keeping out of sight. Most New Guinea endemics have no direct contact with people.
Genus Steonmys has but four species, all of which are endemic to New Guinea: S. niobe, S. richardsoni, S. verecundus and S. vandeusini. In this genus, the tail is as long or longer than the head and body combined. The hind feet are long and slender. The S. richarsoni has been found as high as 4500 m. with the low end of its range at 3325 m. It lives in tussock grasslands and a bare, tundra-like habitat. It’s cold and wet up there year-round. Going almost as high, S. niobe ranges up to 4050 m. and down to 762 m. with the altitude range of the S. verdunus from 150 m. to 2750 m.
The genus Pogonomys, the Prehensile-tailed Rats are also covered by four endemic species found on New Guinea and nearby islands: P. macrorous, P. chamioni, P. syvestris and P. loriae. This last species has recently been seen in Cape York. All four species have long, scantily haired tails, covered with coarse scales. The head and eyes are large. The fore and hind limbs have been modified for climbing trees but it is only partially arboreal. They are found from sea level to 3000 m. Its diet consists of young leaves, bamboo shoots and other buds. Resembling these prehensile-tailed customers, we have the genus Chiruromys, restricted to three endemic species in New Guinea and nearby islands. They are: C. forbesi, C. lamia and C. vates. The difference lies in the tail which, in this genus, has its scales stand out like teeth on a rasp. The genus is entirely arboreal. It forms couples of mated pairs and the young stay with the parents until fully grown or another litter is born.
The genus Mallomys, the Giant Tree Rats, have but four species, all New Guinea endemics and quite common on the montane forests throughout the island where they have not been hunted out or lost their habitat. The species are: M. rothchildi, M. aroaensis, M. istapontop, and A. gunung. Due to their cold habitat, the fur is quite long, thick and wooly. The muzzle is short, the skull thick and heavy. These rats are mainly arboreal and entirely vegetarian. Their large size, from one to two kilos, make them targets for hunter. The teeth are sometimes used for engraving patterns on arrows. Also in the mountains, we find two more endemics, the sole representatives of the Genus Hyomys, the White-eared Giant Rats. The species are H. goliath and H. dammermani. Size ranges from 295 to 390 mm. and weight from 750 to 945 g. These are large, quite bulky animals, more terrestrial than the Mallomys. The eat bamboo and other shoots in the forested hills between 1200 and 3000 m. The single endemic species of the genus Anysomys, the Powerful-toothed Rat, lives up to its name by specializing in cracking hard-shelled nuts. The A. imitator, weighing just over a half kilo, ranges from near sea level to 3500 m.
The Giant Naked-tailed Rats, genus Uromys, is represented by nine species, of which four are endemic to New Guinea and one, U. caudimaculatus, ranging from the Kei and Aru islands through New Guinea, on to the D’Entrecastaux Islands and into Queensland. Their formidable teeth are said to be capable of opening coconuts and even cans of tinned food. Weighing about one kilo, they are mostly arboreal. Aside from coconuts and other nuts, they thrive on fruit and flowers. The indigenous species in New Guinea are the U. boeadii, U. emmae, U. neobritannicus and U. anak.
The genus Melomys, the Mozaic-tailed or Banana Rats, are split into 28 species of which 14 are endemic to New Guinea, with one of these possibly shared with Cape York. Here goes to list: M. fellowsi, M. levipes, M. mollis, M. lorantzi, M. moncktoni, M. rubex, M. platyops, M. rufescens, M. gracilis, M. leucogaster, M. rubicola, M. rattoides, M. lanosus and the possibly shared species, M. lutillus. Like the genus Uromys, this genus can be recognized by almost naked, filelike tail with the scales form a kind of mozaic, differing strikingly from evenly ringed arrangement seen on the tails of typical rats. Most species are forest-dwellers, basically terrestrial but able to climb. Some species are known to occur in plague proportions in Australia. One species is now extinct due to introduced dogs, pigs, rats and the others are endangered due to loss of their limited habitat.
The list of endemics continues with several more genera. Coccyms, with two species, both endemics: C. albidens (found only around Lake Habbema) and C. reemmleri, ranging throughout the mountains. Both species have long, dense fur and are only found in the 1900 to 3600 m. range. The genus Pogonomelomys, known as Rümmler’s Mozaic-tailed Rats, with the species P. mayeri, P. bruijni and P. sevia, the only species of the genus, all endemic. The last named species ranges to 3500 m. We have three monotypic genera, each with only one species, New Guinea endemics one and all: Xenuromy barbatus, the White-tailed New Guinea Rat; Spelaeomys florensis (known only from 3500 year old dental and cranial fragments); and Lorentzimys nouhysi, the New Guinea Jumping Mouse, found throughout the forested parts of New Guinea, nesting in pandanus and similar trees.
The genus Pseudomys, Australian Native Mice, with 24 species, has one lone representative in New Guinea: P. delicatulus, shared with Australia. The last three genera of this subfamily are all endemic to New Guinea: Macruromys elegans and M. major; Paraleptomys wilhelmina and P. rufilatus; Leptomys elegans; L. ernstmayri and L. signatus. All of them are mainly mountain dwellers.
Subfamily Hydromyinae: Water Rats
Genus Hydromys, Water or Beaver Rats, has five species, all of them endemic except for one, H. chrysogaster, shared with south Moluccas and Australia. The other species are H. hussoni, H. neobritannicus, H. habbema and H. shawmayeri. They weight to up to 1.3 kg, with a pelage of shiny guard hairs, and dense, soft underfur. These are large water rats with sleek, streamlined appearance with aquatic adaptations: long and flattened head, forward thrusting nostrils, high-set eyes, small ears, seal-like fur and broad, partially webbed feet. They feed on fish to 30 cm. in length, large aquatic insects, but lots. The H. chrysogaster is trapped in Australia for its beautiful fur pelt.
There are six other genera of water rats endemic to New Guinea. Four of them are monospecific: Neohydromys fuscus, Parahydromys asper (Mountain Water Rat), Crossomys moncktoni (Earless Water Rat) and Mayermys ellermani (Shaw-Mayer’s Mouse). All are mountain dwellers. Two other genera, each with two endemics, round out our list of New Guinea rodents: Pseudomydromys murinus (only 14 specimen ever collected), P. occidentalis (five specimen in collections), Microhydromys richardsoni (known from only four specimen) and M. mussery (known only from the type specimen).
Humans began moving to New Guinea at least 50,000 years ago, but introduced mammals arrived considerably later. Controversy still surrounds the date of the arrival of the first pigs, an integral element in many local cultures. The first and very tenuous date proposed is some 10,000 years ago, but even other evidence, from 6000 years in the past can not be authenticated as definitive. Be that as it may, the now indigenous pig species is probably a hybrid between the common Wild Boar, Sus scrofa and the later introduced Celebes Wild Boar, Sus celebenis which was, formerly, endemic to Sulawesi Island. These pigs are domesticated and still today an essential status symbol and source of wealth in just about all the highland areas.
The dogs, now essential to any hunting expedition, were probably not introduced until 2,000 to 3,000 years ago. The barkless New Guinea Wild Dog is not closely related to the better known Australian Dingo, introduced perhaps a millenia earlier, about 3500 years ago. The barkless New Guinea dogs howl, when their rather euphemistic name of ‘singing dogs’. Their unique vocalizations, including a howling marked by an extraordinary degree of frequency modulation and a number of signals, such as high-pitched rapid trill, has never been reported for other canids. The New Guinea wild dogs make up a distinct population, once given the name of Canis hallstomi, but this did not stick.
Eight rat species have also come along, probably in the past two centuries, as stowaways. Cats are also a recent introduction. The Rusa Deer, Cervus timorensis, was introduced by the Dutch to the dry Merauke area in 1928, but none have made to Kamoroland, with its tropical climate and vegetation. Monkeys have been brought in as pets by Indonesians from the west and it is fervently hoped that any that escape can quickly be eradicated before they wreck ecological havoc.
The deer called Sunda Sambar, Cervus timorensis, was introduced to New Guinea relatively dry south-central region about 1920. They have thrived, multiplied and today are extensively hunted in the Merauke area of Irian Jaya and across the border in PNG as well. Some of these deer are reported to swim in sea, drink seawater, and apparently to relish certain seaweeds.