Fauna of New Guinea
The fauna of New Guinea comprises a large number of species of mammals, reptiles, birds, fish, invertebrates and amphibians.
[1] Nevertheless, despite the rich biodiversity, New Guinea's megafauna diversity is quite low since the Pleistocene extinction event, especially when it comes to apex predators.
Of the three, two are obligate carnivores such as the crocodile monitor and the New Guinea singing dog, whilst one, the cassowary, is actually a frugivore but predatory opportunistically and seasonally.
At this time, a number species existed on both land masses, and many plants and animals thus crossed from Australia to Papua New Guinea and vice versa.
Those closely related to the Australian kangaroos, such as the agile wallaby (Macropus agilis), inhabit the open grasslands of New Guinea.
[10][11][12] The old endemics have undergone an adaptive radiation, which produced such distinctive forms as the small, shrew-like Pseudohydromys, the amphibious Hydromys, tree mice of the genus Chiruromys, and several genera of giant rats, of which Mallomys is the largest.
Bats migrated to New Guinea on many occasions, with many species being shared with Australia, the Sunda Islands and even mainland Asia.
[15] It is abundant throughout the island, and more common in areas where humans grow sweet potato as their primary food source.
The New Guinea singing dogs live in the remote mountains, above human habitation level, and whilst cassowaries still remain the island's largest opportunistic terrestrial predator by technicality,[2] the singing dogs are New Guinea's largest obligate full-time land predator ecosystem-wise.
These birds dominate the jungles and coasts of New Guinea, with adults fearing no enemies as - outside of humans - not even crocodiles were known to attack them.
Likewise, the cassowary is one of the world's most dangerous birds, for it is capable of inflicting fatal kicking-injuries with its powerful legs, and the dagger-like claw on its inner toe.
Additionally, New Guinea's second-largest terrestrial bird is the neighbouring Australian bustard that is only located in the southern portions of the island.
[20][21][22][2] New Guinea, the Amazon rainforest, the Philippines, and New Zealand all share the distinction of having a bird as dominant top predator.
These groups have achieved their greatest evolutionary diversity in New Guinea, for the island is abundant in fruits and nectar-producing plants.
Many of them can change their physical appearance drastically when they display during mating rituals, in which each species has its own elaborate movements, habits and calls, all to attract females.
Closely related to the birds-of-paradise are the bowerbirds, a group of 20 rather drab, stocky and short-plumed birds found in New Guinea and Australia.
The male builds and decorates an elaborate “bower”, ranging from mats, stick towers, avenued chambers to tipi-roofed huts and displays it to the females.
However, in captivity, most such animals lose this toxicity when fed a diet of non-toxic insects (crickets, fruit flies, etc).
The cane toad was introduced from Australia in 1937 to control hawk moth larvae, which were eating sweet potato crops; they have since become common in non-forested areas.
The common Asiatic toad was accidentally introduced, and is very abundant in a small area in the north-west, and may be spreading further throughout the island.
Excluding Lechriodus, the rest of the myobatrachids are mostly restricted to savannah in the southern Fly and Digul River plains.
Nyctimystes are arboreal frogs, which lay their eggs in fast flowing streams, behind a rock to avoid it being flushed away.
New Guinea and Australia have been absent of Ranids for most of their history, however since the continent's collision with Asia, species have begun to move across.
A striking example of a biogeographic border for freshwater fauna are the New Guinea Highlands, and the species diversity is higher south of the chain than north of it.
Among strict freshwater fish, only two species (Chilatherina campsi and Oxyeleotris fimbriata) are found both north and south of these highlands.
[28] There are several large river systems in New Guinea, including the Fly, Sepik and Mamberamo, which all are rich in fishes.
[28] Other crustacean genera known from New Guinea freshwater are Atya (2 species) and Palaemon (2) shrimps, and Geelvinkia (3), Halicarcinus (1), Pseudograpsus (1), Ptychognathus (1), Rouxana (5) and Varuna (1) crabs.
Over the Tertiary it consisted of a land mass (often called the Melanesian continent) more isolated than the present New Guinea, and farther to the northeast.
In the Pliocene New Guinea rose from the sea bottom, and in the Pleistocene connected with Australia for a sufficient period to permit faunal exchange.
The Papua Insects Foundation provides an expert resource [44] Notable endemic insect species include Ornithoptera paradisea, Ornithoptera chimaera, Papilio weymeri, Graphium weiskei, Ideopsis hewitsonii, Taenaris catops, Parantica rotundata, Parantica clinias, Rosenbergia rufolineata, Mecopus doryphorus, Mecopus serrirostris, Sphingnotus mirabilis, Sphingnotus insignis, Belionota aenea, Poropterus solidus, Poropterus gemmifer, Promechus splendens, Aporhina bispinosa, Eupholus petitii, Eupholus bennetti, Schizoeupsalis promissa, Barystethus tropicus, Eupholus geoffroyi, Rhinoscapha loriai, Rhinoscapha funebris, Rhinoscapha insignis Alcides exornatus, Alcides elegans, Xenocerus lacrymans, Arachnobas sectator, Arrhenodes digramma, Eupholus magnificus, Mecopus bispinosus, Callictita spp.. Also known from New Guinea are Batocera wallacei, Ithystenus curvidens, Meganthribus pupa, Sipalinus gigas, Pelargoderus rubropunctatus, Rhynchophorus bilineatus, Gasterocercus anatinus, Acalolepta australis, Actinus imperialis, Megacrania batesii.
