Marsupials give birth to very immature young and carry them in a maternal pouch. Kangaroos are marsupials found only Australia and New Guinea. Although not usually seen in large cities, kangaroos are easy to spot outside heavily urbanized areas. Koalas are a favourite with tourists, but most do not get a chance to see one in the wild. These marsupials dwell high up in Australia's eucalyptus trees and usually sleep during the day.
Koalas are dependent on Australia's eucalyptus trees as their only source of food.
Unfortunately, despite the great biodiversity and relatively low human population, the rate of mammalian extinction is greater in Australia than anywhere else in the world. Two hundred years ago there were about 144 different kinds of marsupials, now there are only 134. Nineteen other marsupial species are endangered. Extinction has occurred partly because of the introduction of new species to Australia. In 1935, the poisonous cane toad was imported from Hawaii to decrease the number of cane beetles, which were eating sugar cane.