There are over 650 different species; 454 are indigenous (live here and breed year round) and 36 are endemic (found nowhere else in the world). These include the fabulous Birds of Paradise (36 different species), bowerbirds, crowned pigeons - the largest pigeon in the world, cassowary - the flighless cousin of Australia's Emu and the pitohui, the only poisonous birds in the world (discovered only 2 years ago - though known to the the native inhabitants).
Distribution of the birds in the various habitats through Irian Jaya also makes an interesting study and this also points to the geological developments that contribute heavily to all this diversity. The field guide "Birds of New Guinea" identifies 15 distinct bird regions characterized by the birds resident in the region, topography and climate.
Sir Alfred Russel Wallace opened the world’s eyes to Irian magnificent biological diversity. Between 1854 and 1862, Wallace sent a total of 125,660 specimen back to England, including a staggering 83,200 Coleoptera (beetles). A talented and scrupulously honest writer, Wallace estimated that he traveled 14,000 miles within the archipelago on some 60 to 70 separate journeys.
Wallace was the first to recognize the marked change in faunal types as one move east Bali from the Asian to the Australian biological regions. The large area of biological overlap in between, including Sulawesi, the Moluccas, and Nusa Tenggara, is now called “Wallacea” in his honor.
New Guinea is well on the Australian side of Wallacea. Since the Arafura Sea is quite shallow, the rising and falling of the sea brought on by the ice ages have caused the two land masses to have periodically connected. Because of this-and because of the existence of marsupials and monotremes in both paces-New Guinea is typically considered part of the Australian faunal province.
But recently biogeographers have suggested that the Australian influence may be exaggerated. For examples, the land bridge connecting the two was always a dry savannah belt, which would have been a very effective barrier to rainforest species. Further, the majority of amphibian species and many of small mammals in New Guinea are Asian in origin.
So far, biologists have identified 643 species of bird Irian Jaya (172 in all of New Guinea), and there some real gems in this group. The Victoria crowned pigeon (Goura spp.), the world large pigeon, is a brilliant lavender with a delicate crown of feathers and bright red eyes. Parrots, cockatoos, and lories brighten up the forest with red, yellow and purple. During his eight years in the archipelago, Wallace spent six months in what is now Irian, three months on the shore of Dore Bay and three months on Waigeo Island. Approaching the coast of the first time, Wallace tingled with anticipation, knowing that “those dark forest produce the most extraordinary and the most beautiful of the feather inhabitants of the earth”-the bird of paradise.
Irian is home to some strange birds as well. The megapods or brush turkeys, which bury their eggs in sand or piles of vegetation, are found here. Bower birds, industrious creatures that decorate their large nets with bright object such as flowers and berries, sometimes collecting small piles of object of single color, are present here in 9 species. One of the most famous of Irian’s birds is the cassowary (casuaris spp.), a large, flightless bird with a nasty reputation. These ugly customers have powerful feet ending in large claws, powerful weapons that have disemboweled more than human victim. These birds are sought by hunters everywhere there are found, and the hair-like feathers are a common decoration on hats and other items.
Marsupials dominate the list of mammals indigenous to Irian. Unlike placental mammals, young marsupials complete their gestation in an external pouch. Wallabies and tree kangaroos, found in the lower mountain regions, are the largest Irian’s Native, landwelling mammals.
Other marsupials include bandicoots, possums and cuscus or phalangers, these latter wooly, tree-dwelling creature with prehesile tail. Unfortunately for the cuscus, its fur is much appreciated for personal adornment, as its is meat. Some cuscus are said to be so docile that capturing one requires nothing more than finding it and pick it up. Huge bats, called flying foxes because of their long snouts, roam the forest on 1.5 meters wings seeking fruit, and an astonishing variety of tiny insectivorous roam the night skies.
Perhaps the most unusual mammals in Irian are the spiny anteaters or achidnas which, along with Australian duck-billed platypus, are the world’s only monotremes, unique egg-laying mammals. The shortbeaked echidna (Zaglossus bruijni) is endemmic to New Guinea. When threatened, the echidna uses the powerful front claws to dig into the ground, presenting a would-be predator with a back-full of stout spines.
The same cannot be said for the death adder (Achanthopsis antarcticus) or the taipan (oxyuranus scutallatus). These two are extremely venomous, but fortunately are rarely encountered. The most beautiful snakes found here-perhaps any where-is the green tree python (Chondropython viridis), the harmless creature with strikingly green coloration and jewel-like markings. The only amphibians native to the island are frogs (the large marine toad has been introduced), but there are more frogs in New Guinea than anywhere else, with well over 200 species, some hardly ones found up to 3,850 meters.
The swampy south coast Irian is too silty to allow the growth of coral, but around Triton Bay near Kaimana, off the Raja Empat Islands, and around the islands of the Cendrawasih Bay are some of the fines and least disturbed coral reefs in the world. Since it is so close to the epicenter of species diversity for the vast Indo-Pacific region, New Guinea coral reefs probably harbor some 3,000 species of fish. Important food fish-tuna, jacks, mackerel-support a large fishing industry of Biak Island. Irian’s freshwater lakes and streams contain 158 species of the rainbowfishes. These small, and often colorful fishes are found only in New Guinea and Australia and are favorites with aquarists.
The Archer fish (toxotes spp.) is a small, unremarkably colored in habitant of some of Irian’s Lake, slow rivers and swamps. This animal’s talent is the ability to spit a gob of water-with astounding accuracy-to bring down insects. The insects are gobbled up as soon as they strike the surface of the water.
Some of the Irian’s freshwater species are giants. The sawfish (pristiopsis spp.) prowls the large river system and Irian’s lakes, including lake Sentani. These distinctive animals can reach 5.2 meters, and weight almost half a metric ton. The people living around Sentani believe their ancestral spirits live in these sawfish and refuse to eat them. Lake Yamur, at the base of the Bird’s Head, is said to be one of the very few places in the world that one encounters freshwater sharks.
The colorful princes of Irian’s insect fauna are the birdwing butterflies (Ornithoptera spp.), which can be found in all parts of New Guinea but reach their greatest numbers and diversity in the Arfak Mountains just inland for Manokwari. These butterfly are covered with simmering colors. Recently a captive farming project has begun to raise these creatures for the lucrative export marked in dried and muouted butterflies.
New Guinea probably has almost 100,000 insect species, and many of these are still undescribed. In the forest one can find great stick insects and katydids-some of them startlingly accurate mimics-as well as tens of thousands of species of beetles.