What Rats Are Native to Australia?

Australia has a number of rat species. Rats first arrived here, along with other marsupials, such as kangaroos and wombats. Its diversity makes it an invaluable laboratory for evolutionary biologists. Its native range used to stretch from WA to central Australia, but today, the population is restricted to a few high mountain ranges near Alice Springs.

There are 60 species of native rodents in Australia. Eight are Rattus, which evolved from ancestors who arrived here about a million years ago. They are similar to black rats, though they are smaller and chubbier. The largest native species, the brown rat, is twice as long as a black rat.

Water rats in Australia are native to Australia. They are large rodents, reaching a weight of 1.3 kilograms. They are believed to have dispersed to Australia from New Guinea. Their tails are adapted for swimming, serving as rudders. Moreover, their hind feet are partly webbed and have a broad palm for efficient paddling.

Rattus fuscipes is a nocturnal new endemic species that has recently spread to eastern Australia. However, it is relatively rare on the Beecroft Peninsula, possibly because of competition with R. rattus, which is native to the region. Both species share a similar diet, but despite their different appearances, they have a mutualistic relationship.