rewrite

The Koala bear is native to Australia, which is about the size of the United States. But this small, tree-living animal is recognized and loved the world over for its unique and alluring features.

The koala's proper genus and species name is Phascolarctos cinereus, meaning "pouched bear" in Latin. This is because koalas, like kangaroos and a variety other Australian creatures, are marsupials, which give birth to very immature babies and therefore have to carry them in a bodily pouch for some time after they are born.

The physical adaptations the koala has made throughout its evolution in response to its natural habitats include unique paws, a dense woolly coat and an extremely slow metabolism.

The koala is so different even from other marsupials that it has been assigned its own taxonomic family. Its pouch, like that of wombats, is on its back, making tree climbing easier. They live in wooded areas, which in Australia are confined to the eastern and southern portions of the island continent.

Koalas are recognizable because of their round head, large furry ears and oversized black nose. Their fur is usually grayish-brown with scattered white fur on the chest, arms, ears and rump. Adults can weigh anywhere from 4 to 14 kg (about 10 to 30 pounds).

Koala paws are padded, which permits a better grip during tree climbing. Their long sharp claws also help in this endeavor. The front paw, which has five digits and two opposable thumbs, is different from the hind paw, which has four digits and one thumb. Two thumbs per paw in the front allows for a more secure grip on tree branches. The difference between front and back results from the second and third digits of the hind paw being fused to form one two-clawed "finger."

A thick, woolly, water-resistant coat of fur protects koalas from both hot and cold conditions as well as moisture from rain. The color of the fur varies with different regions of Australia. In the south, which gets more sun, koala bear fur tends to be darker and thicker than it is farther north. The fur on the rump has evolved as padding, because the koala continually sits on hard wooden branches.

Koalas live almost entirely on eucalyptus leaves, which are poisonous to all other known mammals. It can be choosy when it comes to what kind of eucalyptus. This is one of the strangest koala adaptations, but it's really a simple consequence of what grows in the koala's habitat. They will also sometimes consume buds, bark or fruit.

Because this diet provides little energy, koalas have very slow metabolic rates, sleeping as much as 22 hours per day.