The Koala is perhaps the best-loved of all Australia’s marsupial, or pouched, mammals. Extra thick fur, especially on the neck and shoulders, helps protect the Koala from even the worst weather (Koalas do not build nests). Opposable thumbs and toes allow for a tight grip when climbing. The Koala cools itself by licking its arm and stretching out as it rests in the trees (Koalas have no sweat glands). The Koala spends most of its time shuffling around the topmost branches of the Eucalyptus, or “gum” trees, hanging on tight with its four grasping feet. It sleeps during the day, curled up in a tree-fork and at night on the leaves and shoots of a few species of Eucalyptus. An adult will eat 500g of leaves a day. The name “koala” means “no drink” and rarely does so. It occasionally comes down to the ground, either to eat soil, which is thought to aid digestion, or to move to another tree.

Koala is the only mammal which can survive on a diet of eucalyptus leaves. Koala seldom drinks water obtaining it from the eucalyptus leaves, which are 50% consisting of water. Although, they drink water if due to drought the leaves water content is reduced. Koalas have a slow metabolic rate due to their high-fiber, low nutrient diet. Because they store little or no fat, koalas must adopt strategies that conserve energy. Sleeping is one of them. Koalas sleep for up to 16 hours per day in order to conserve energy. Koalas spends 75% of its time sleeping. Eucalyptus foliage is very fibrous and low in nutrition, and to most animals are extremely poisonous. Koalas are not drugged out on gum leaves. Koalas digestive system is especially adapted to detoxify the poisonous chemicals in the leaves.

Koalas breed once a year. Mating normally occurs from September to March. The baby Koala, “joey” is blind, hairless, less than one inch long and weighs less than 1 gram. It then crawls into its mothers pouch completely unaided, relying on its sense of smell, strong forelimbs and claws. If a female does not reproduce each year, the young koala stays with her longer and has a greater chance of survival.