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The fauna of New Guinea comprises a large number of species of mammals, reptiles, birds, fish, invertebrates and amphibians. As the world’s largest and highest tropical island, New Guinea occupies less than 0.5% of world's land surface, yet supports a high percentage of global biodiversity. Approximately 4,642 vertebrate species inhabit the island of New Guinea and its surrounding waters, which constitutes about 8% of the recognized world vertebrates. This ranges from an estimated 4% of the world's lizards and mammals, to about 10% of the world's fish species.• The numbers of global and New Guinea invertebrate species are poorly known, and thus an accurate comparison is difficult. Butterflies are the best known invertebrate group, and are represented in New Guinea by about 735 species, which is about 4.2% of the world total of 17,500 species.•
Origin New Guinea is a large island located north of Australia, and south-east of Asia. It is part of the Australian Plate, known as Sahul, and once formed part of the super-continent Gondwana. The origin of most New Guinea fauna is closely linked to Australia. Gondwana began to break up 140 million years ago, and Sahul separated from Antarctica 50 million years ago. As it drifted north, New Guinea moved into the tropics. Throughout New Guinea's geological history there have been many land connections with Australia. These have occurred during glaciations in various ice ages. Four occurred during the Pleistocene; the last of which was severed 10,000 years ago. At this time, a number species existed on both land masses, and many plants and animals thus crossed from Australia to New Guinea and vice versa. Many later became isolated as the connection ended, then further evolving to the new environment and becoming distinct species. However, this Australia-New Guinea mixing occurred among a relatively few faunal groups; some New Guinea species have an Asian origin. As New Guinea drifted north, it collided with the Pacific Plate as well as a number of oceanic islands. Although no land connection with Asia was ever formed, the proximity between the landmasses, via the many small islands of the Indonesian archipelago, allowed some Asian species to migrate to New Guinea. This has resulted in a unique mixture of Australian and Asian species, seen nowhere else in the world. A large percentage of New Guinea's species are endemic to the island. History of study Influential evolutionary biologist Ernst Mayr came to New Guinea in 1928 to make collections for the American Museum of Natural History and banker and naturalist Walter Rothschild. Mayr collected several thousands bird skins (he named 26 new bird species during his lifetime) and, in the process also named 38 new orchid species. He determined that New Guinea's rarest birds of paradise were, in fact, hybrid species. During his stay in New Guinea, he was invited to accompany the Whitney South Seas Expedition to the Solomon Islands. Mayr's experience of the fauna of New Guinea informed many of his conclusions about evolution for the rest of his life. Mammals The mammal fauna of New Guinea is comprised of all extant subclasses of mammal: the monotremes, placentals and marsupials. New Guinea contains the largest number of monotreme species of any land mass, with only one species absent: the Platypus (Ornithorhynchus anatinus). The marsupial fauna of New Guinea is diverse, consisting of the three orders: Dasyuromorphia, Peramelemorphia and Diprotodontia. The native placental mammals are solely represented by the rodents and bats. There are approximately the same number of placental species as maruspials and monotremes. Monotremes and marsupials New Guinea's monotremes are restricted to the family Tachyglossidae, also known as echidnas. There are four species of echidnas in two genera: the Short-beaked Echidna (Tachyglossus aculeatus), the Eastern Long-beaked Echidna (Zaglossus bartoni), the Western Long-beaked Echidna (Zaglossus bruijni) and Sir David's Long-beaked Echidna (Zaglossus attenboroughi). The genus Zaglossus is endemic to New Guinea, though fossils have been found in Australia. The native mammal fauna of New Guinea lacks large predators. The carnivorous marsupials, Dasyuromorphia, of New Guinea are all small in comparison to Australian species, and most are insectivorous. The largest is the Bronze Quoll (Dasyurus spartacus), a rare quoll, first discovered in southern New Guinea in 1979. It reaches a snout to vent length of 36 centimetres (14.2 in). Fossils of larger marsupials have been found, including the carnivorous Thylacine (Thylacinus sp.), however evidence of carnivorous megafauna, such as the marsupial lion (Thylacoleo), has not been found. The kangaroos, Macropodidae, of New Guinea are very varied in their ecology and behaviour. Those closely related to the Australian kangaroos, such as the Agile Wallaby (Mocrpus agilis), inhabit the open grasslands of New Guinea. However, the tree-kangaroos, which are mostly endemic to New Guinea, are different in appearance and behaviour. As suggested by their name, they are arboreal. They have a long, thick tail which enable them to balance in trees, and large, strong forearms for gripping to trees. Two species of tree kangaroos are also found in Australia, they are believed to have migrated from New Guinea during the Pleistocene. The cuscus, family Phalangeridae, are a family of marsupials closely related to the possums of Australia. The cuscus have evolved in New Guinea, and are found throughout the island. Most species are dark brown or black, however two species, the Common Spotted Cuscus (Spilocuscus maculatus) and Black Spotted Cuscus (Spilocuscus rufoniger), are black, orange and yellow. Many small, herbivorous possum species are native to New Guinea. These include the families: Acrobatidae, Burramyidae, Petauridae and Pseudocheiridae. The Sugar Glider (Petaurus breviceps) is the only New Guinea possum which can glide. It has large flaps of skin between its legs, which it spreads whilst in the air. Three sub-species are found in New Guinea, and they inhabit the entire island. Placental mammals The rodents are solely represented by the family Muridae, and within this family, 23 genera are native to New Guinea. They are believed to have migrated to New Guinea during two different periods. The first group, called the "old New Guinea endemics", are murids which are distantly related to those of the rest of the world and may have migrated to New Guinea during the Miocene.The second group are those of the genus Rattus. These are believed to have moved to New Guinea when humans first colonised. Many of the Rattus species introduced early in human's history have evolved, and are endemic to New Guinea. The two most diverse groups of rats found in New Guinea are the old New Guinea endemics and the hydromyines. The old New Guinea endemics contain 11 genera, spread throughout the island. The old New Guinea endemics contain the largest rat found in New Guinea, the Grey Black-eared Giant Rat (Mallomys aroaensis); males can reach a length of 41 centimetres (16.1 in) from snout to vent. The bats of New Guinea are a very diverse group, comprising 6 families, and 29 genera. The six familes are: Pteropodidae, Emballonuridae, Hipposideridae, Rhinolophidae, Vespertilionidae and Molossidae. Much like the rodents, bats migrated to New Guinea on two different occasions. The megabats, or Megachiropterans, of New Guinea are highly adapted, and many are endemic to New Guinea and surrounding islands. While most megabats are herbivorous, and eat fruit, nectar and flowers, some species within New Guinea have adapted to also eat insects whilst in flight; an ecological niche usually filled by microbats. Some species also forage on the ground, an adaptation not seen in areas with large predators. The microbats, or Microchiroptera, show much less endemism than the megabats. Only one genus and a few species are endemic to New Guinea and surrounding islands; this suggests a much later migration to New Guinea. The colonisation of New Guinea by Humans (Homo sapiens) occurred at least 40,000 years ago. Since their original colonisation, many mammals have been introduced both by accident, and on purpose. The Wild Boar (Sus scrofa) was introduced to New Guinea at least 6,000 years ago, though may have been introduced 12,000 years ago. It is abundant throughout the island, and more common in areas where humans grow sweet potato as their primary food source. The Wild Boar is a large forager, and disturbs the forest floor whilst looking for food. This disturbance may have an effect on the native flora and fauna. The Dog (Canis familiaris) was introduced to New Guinea about 2,000 years ago. The Dog is mostly kept by humans, however many are wild. The New Guinea Singing Dog (Canis hallstromi) is a wild dog which is similar to the Australian Dingo (Canis lupus dingo). It does not bark, but howls in a chorus, hence the name. Many murid species have been introduced to New Guinea. These include: the Polynesian Rat (Rattus exulans), the Himalayan Field Rat (Rattus nitidus), the Black Rat (Rattus rattus), the Rice Field Rat (Rattus argentiventer), the Brown Rat (Rattus norvegicus) and the House Mouse (Mus musculus). Most of these have not caused much damage, and most have only established in human settlements. The House Mouse is the most wide-spread of the introduced murids, and is found in settlements and grassland. It is the only introduced murid to reach central region of Telefomin. Three species of deer have been introduced to New Guinea. The Rusa Deer (Cervus timorensis) is the most common, and well established. It is found throughout the north and south of New Guinea. It is commonly hunted for meat by humans. The other two species, the Chital (Axis axis) and the Fallow Deer (Dama dama) are much rarer, and the Fallow Deer may be extinct. The Cat (Felis cattus) is common around human settlements, but is rare in the forested regions of New Guinea. In areas where it has established, native animal populations have dramatically decreased. Birds
Amphibians The amphibians of New Guinea, like most Gondwanan continents, are restricted to those of the order Anura, known as frogs and toads. There are six families represented in New Guinea. Four of these: Myobatrachidae, Hylidae, Ranidae and Microhylidae are native. Two specimens of Rhacophoridae, a family well represented in Asia, were discovered in 1926. It is thought they were introduced by humans, but have since become extinct on the island. The other family, Bufonidae, is only represented by one species, the Cane Toad (Bufo marinus). It was introduced from Australia in 1937 to control hawk moth larvae, which were eating sweet potato crops. The introduction was successful, however the Cane Toads have since become common in non-forested areas. Frogs from the family Myobatrachidae are very diverse in Australia, but not many species have established in New Guinea. This is believed to be because of the climate and vegetation type. Myobatrachids in Australia mostly inhabit open grasslands, or even desert. New Guinea, however, is mostly covered in dense rainforest. The most common Myobatrachid in New Guinea is the Wokan Cannibal Frog (Lechriodus melanopyga). It is a small ground-dwelling frog common throughout New Guinea. The Lechriodus genus, is the only Myobatrachid genus with greater diversity in New Guinea than Australia. Tree frogs have successfully inhabited New Guinea. They are the most diverse family of frogs in New Guinea with over 100 species, and many more to be described. There are two genera represented in New Guinea, Litoria and Nyctimystes. Litoria are found throughout both Australia and New Guinea, however, only one of the 24 species of Nyctimystes has reached Australia. Nyctimystes are arboreal frogs, which lay their eggs in fast flowing streams, behind a rock to avoid it being flushed away. The tadpoles have modified mouths, which use suction to stick to rocks. Ranidae, also known as true frogs, are the most widely distributed family of frogs on earth, however, they are not well represented in Australia or New Guinea. 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. The Ranids in New Guinea are only represented with one genus, Rana. Although the origins of Microhylidae in New Guinea are very similar to the Ranids, there is much more diversity. The Microhylids are represented by twelve genera in New Guinea, four of which are endemic. Reptiles The reptile fauna of New Guinea is represented by three of the four extant orders. The squamates, also known as the snakes and lizards, represent the largest group, with approximately 300 described species. The remaining two groups: testudines, or turtles and tortoises, and Crocodilia, the crocodiles, are much less diverse. The turtles are represented by thirteen described species, and the crocodiles two. The lizards of New Guinea are represented by approximately 200 described species. Of these, a majority are skinks with a smaller number of Geckos and Agamids. The snakes, approximately 100 described species, show a much lower rate of endemism than most of New Guinea's fauna. The turtles of New Guinea are almost equally represented by fresh water turtles as marine. Six species of New Guinea's turtles are marine, and all are found on other land masses. The fresh water turtles are represented by seven species, with three endemic to New Guinea. One species, Parker's Snake-necked Turtle (Chelodina parkeri), is restricted to the Fly River. The Saltwater Crocodile (Crocodylus porosus) is the largest reptile native to New Guinea. It is a widely distributed species, from eastern India to northern Australia. It is found in most of New Guinea's rivers, except for those heavily disturbed by humans, or too small to accommodate the species. The other crocodile native to New Guinea, the New Guinea Crocodile (Crocodylus novaeguineae), is an endemic. It is much smaller than the Saltwater Crocodile. A separate species may occur in southern New Guinea. Notes See also | ||||||||||
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