Australia's very distinctive fauna includes 800 species of birds of which 400 are found nowhere else, 300 species of lizards, 140 species of snakes, 230 species of native mammals, and 2 species of crocodile. These unique animals evolved during the 55 million years that the continent has been isolated from other land masses.

There are two predominant kinds of native mammals in Australia, the monotremes and the marsupials. The monotremes are egg laying mammals; the marsupials give birth to young in a very immature state which are carried in a maternal pouch.

There are two kinds of monotremes; the platypus and echidna. There are hundreds of kinds of marsupials, including koalas, wombats, and more than 50 species of kangaroo. Monotremes are often called "living fossils" because they are egg laying mammals and are considered to represent the stage of evolution between reptilian and placental mammals.

Isolation also allowed for the evolution of exotic birds. Over 400 species of bird are found nowhere else, and the birds are as numerous as they are colourful. They range from the tiny honeyeaters to the large, flightless Emu which stands over two meters tall. There are 55 species of parrots in Australia; an early map by one of the earliest navigators suggested the Australian continent should be called "Terra psittacorum", Latin for "land of Parrots".

The Kangaroo is unique to Australia and New Guinea, its hind limbs are longer than its forelimbs, it has a front opening pouch, and a large muscular tail. A baby kangaroo is only partially developed at birth, and must reach the safety of its mother's pouch unassisted. Kangaroos are extremely social animals, and travel in groups.

Koalas rarely leave their trees, and then it is only to reach the safety of another tree. Koalas mature slowly over a period of three to four years, once they are mature they are capable of reproducing every year. Despite heavy hunting, disease, and the loss of their habitat, koalas, now protected, are making a comeback. 

Wombats are small, bear-like animals, with a large blunt head and short-legs. The female has a pouch containing two teats. The baby wombat is born in Autumn and weaned in the Spring. A slow animal, the wombat can sometimes obtain speed in a clumsy gallop. 

The platypus can only remain under water for two to three minutes before it has to resurface. It is notable for its unusual appearance, and it is often regarded as the missing link between sea mammals and land mammals. It collects food from along the river-bed, and stores it in a pair of duck-like cheek pouches. 

The echidna is a small monotreme, with a long slender snout, short-legs, long spines, and sticky tongue, for the collection of ants. It is most famous for its bizarre defensive manoeuvre of digging itself vertically into the ground. The echidna lays its egg directly into the pouch, where it is hatched, and the young is kept there until the development of its spines. 

Emus are the world's second largest bird, and Australia's largest. They stand 1.5m high and weigh up to 55kg. Flightless, they can run up to 50kph. It breeds from April to November, laying six to twelve eggs. Their nests are a circle of stone and grass. 

There are fifty-five Australian species of Parrots, more than a fifth of the world's parrot population. These colourful birds vary widely from region to region. Most have a strong hooked bill, and two claws, two toes in front and one in the back. Most nest in trees, but some nest on the side of cliffs, and lay two to four eggs.

Australia has two species of crocodile, freshwater and saltwater, and although their fearsomeness has often been exaggerated, they are a dangerous animal. Crocodiles are the closest living relative to the dinosaurs, and can out-run a man on land. It is not uncommon to hear about one taking cattle or horses, and they have been known to attack humans.

There are over 520 species of lizards found in Australia, out of these only one group of lizards appears to have evolved completely in the Australian region. The five main families of lizards are Geckos, Legless lizards or Snake lizards, Dragon lizards, Monitor lizards or Goannas, and Skinks.

The blight that hoofed mammals – horses, cows, sheep and goats – have perpetrated on Australia’s fragile fauna is horrendous. Much of the country has been prematurely desertified by their eating habits, abrasive hooves and demand for water; once extracted from below ground, it is not replenished, which alters the mineral balance and kills remaining plant life. 

The damage caused by rabbits is equally all-pervasive, especially in the semi-desert areas where their cyclic population explosions can strip every shred of plant life from fragile dune systems. However, a recently engineered virus has massively reduced their numbers. Feral cats, which hunt for sport as well as necessity, are currently seen as the greatest threat to the indigenous fauna, primarily small marsupials and birds.

For more information on Australian Fauna, go to:

• Birds Down Under
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