This region includes Australia, Tasmania, New Guinea, New Zealand and islands east of Wallace’s Line. New Guinea is tropical with rain forests. Eastern Australia is covered with lush green forests, Western Australia is desert and there are grasslands in the middle.
Mammals. Eight of the 9 families of marsupials are unique. There are 52 genera of 6 families of marsupials that are unique and are not found in the Neotropical Region. Marsupials show parallelism with their counterpart placentals in other parts of the world in their evolutionary modifications.
Placental mammals that were introduced by man or some of them immigrated themselves include rodents and bats, rabbits, foxes, rats, mice, dingo dogs, cats, pigs and murid mice.
Monotremes are represented by Ornythorhynchus and Echidna.
Birds. There are 58 families of birds out of which 44 are widely distributed. Species having wide range are trogons (Harpactes), hawks, kingfisher, cuckoos, parrots and pigeons.
Shared with Oriental are frogmouths, wood-swallows, flowerpeckers and megapods.
There are 10 families of endemic birds which include cassowary, emu, kiwi, lyrebird, bower birds, honey suckers, birds of paradise, magapods and cookabura or laughing jackass that feeds on lizards and snakes.
Birds not present are pheasants, finches, barbets and woodpeckers.
Reptiles. There are pythons, biting snakes, elepid coral snakes, geckos, skinks, agamid lizards, scale-footed lizard (Pygopus) and Komodo Dragon (Varanidae), crocodiles and turtles. Chelyd turtles and snake-necked turtles (Chelodina) possess strikingly long necks. Sphenodon pounctatus is found exclusively in New Zealand.
Amphibia. There are no tailed amphibians. Common toads are absent and frogs are few. Tree frogs belong to family Hylidae which is also found in the New World and Palaearctic but absent in African and Oriental Regions. The Australian Green Tree Frog secretes mosquito repellent compound from the skin glands. The Australian frogs, Rheobatrachus silus and R. vitellinus carry tadpoles in their stomachs. Some species of frogs are adapted to live in deserts, e.g. Notaden, Neobatrachus and Helioporus.
Fishes. Fresh water fishes are rare and belong to family Osteoglossidae. Lung fish (Neoceratodus) is restricted to Burnett and Mary rivers in Queensland.
Fauna of this region is poor in freshwater fishes, Amphibia and reptiles. There is uniqueness of mammals and affinities exist with the Oriental and South American faunas.
SUBREGIONS OF AUSTRALIAN
1. Australo-Malayan. Malayan Archipelago, Moluccas, Solomon Islands, New Guinea. Fauna includes 130 families of vertebrates. Birds are crowned pigeons, birds of paradise, honey eaters, cuckoos, bover birds, cassowaries. There are fly river turtles, flying phalangers and tree frogs.
2. Australian. Australia and Tasmania. There are 98 families of vertebrates and the region is home of monotremes and marsupials. Monotremes include short-nosed echidna, long-nosed echidna and duck-billed platypus. Marsupials include marsupial rat kangaroos, Tasmanian devil, koala, the horny possum, marsupial mole and rabbit-eared bandicoot. Tasmanian wolf (Thylacinus cynocephalus) became extinct in 1936. There are scrub birds, lyre birds, emus and plenty of cobras. Tailed amphibians are absent.
3. Polynesian. Polynesia and the adjoining islands. Fauna is poor containing only 53 families. Tooth-billed pigeon is unique.
4. NewZealand. New Zealand, Norfolk Island, Auckland and Campbell Island. Fauna includes murid bats, owl parrots, nester parrots, kiwi, Sphenodon and frog (Liopelma).
Flightless owl parrot or Kakapo feeds on leaves, shoots, berries, fruits and moss. The only carnivorous parrot called KEA was a vegetarian earlier but after introduction of sheep in New Zealand has learnt to cut sheep skin and feed on flesh.
Giant Moa (Dinornis maximus) that reached a height of 3 metres contained 22 species in New Zealand which became extinct all by 1600 AD.