Although the koala is called a koala bear, as it looks like a teddy bear, actually it is a marsupial or pouched mammal and related to the kangaroo and the wombat. The tree-climbing and leaf-munching cuddly Koalas, with strong clawed feet, perfect for living in the branches of trees, are found mainly in the eucalyptus, along the coastal areas of the eastern and southern regions of Australia.
The word koala originated from an Aboriginal term ‘Dharug gula’, which means; ‘no water’. In fact, as the animals were rarely seen by anybody while coming down from the tree, it was maintained by those people that the animal does not need to drink water, as the leaves of eucalyptus tree have high water content. However, the notion was proved to be a myth.
With the body length of 24-33 inches and weighing up to 14 kg, the virtually tailless Koala has a pale yellow or cream-coloured chest and mottling on the rump. The broad face has small yellow eyes, big fluffy ears and a large, spoon-shaped nose.
A koala feeds mostly on eucalyptus leaves and devours a huge quantity for its size, which is about 1.5 kg of leaves a day. To aid the digestion of the massive load of leaves it consumes, the koala is equipped with an intestinal pouch, where a special type of bacteria, known as symbiotic bacteria, degrade the tannin and all other toxic and complex substances in eucalyptus. However, as the diet is relatively poor in nutrients, a Koala does not have sufficient energy to spare and are largely sedentary, spending long hours simply sitting or dozing or sleeping as long as 18 to 20 hours a day, tucked into forks or nooks in the trees.
After a gestation of 34 to 36 days, a Koala mother usually gives birth to one cub at a time. The newborn koala, known as joey, is blind, naked, and earless. However, immediately after the birth, using its strongly developed sense of smell and touch, it instinctively makes its way from the birth canal to its mother's pouch with its strong front legs and claws. For up to six weeks, it is weaned on a soupy predigested eucalyptus called pap that comes from the mother's intestines and contains bacteria that the joey needs to have in its own intestines for enabling to digest its future adult diet of eucalyptus leaves. The little koala leaves the pouch to eat leaves at about seven months, but returns to it to nurse and rides on its mother's back or clings to her belly, accompanying her everywhere, till it completes the first year of its life. In the wild, a koala can live to about 15 years of age and somewhat longer in captivity.
During the 1920s and 1930s, the population of koala plunged considerably due to random killing for the fur trade. Today, though they are not classed as an endangered species, habitat loss is their greatest threat, as Australia's woodlands continue to shrink due to agriculture, urbanization, drought and bushfires.