Koalas are indigenous to Australia and live in tropical to temperate eucalypt forest and woodlands and can be found along the eastern and south-eastern coastal regions. They live in eucalyptus trees and are mostly nocturnal and eat certain types of eucalypt leaves exclusively.
They breed from September to February. Females breed from 2 years of age, and males from 3-4 years after they have established their own territory. Males are extremely aggressive during mating periods. Thirty-five days after mating, the female produces one joey weighing about 0.5 grams and about 2 cm long.
Koalas have woolly light to dark grey fur with brown and white patches and a cream belly. They have a broad head with small eyes, large furry ears and a distinctive large black nose. Females has two teats and a rear opening pouch.
Northern koalas can grow to 740 mm and 9 kg for males and 720 mm and 7.25 kg for females.
Southern koalas can grow to 820 mm and 15 kg for males and 730 mm and 11 kg for females.
They can live for up to 18 years for females and a bit less for males.
They spend up to 20 hours per day sleeping and the rest eating.
Koalas can leap up to 2 meters between trees, and can swim. They curl up into a ball to keep warm and spread out to keep cool.
They are marsupials, not bears. When they are born they are no bigger than a jellybean.
Koalas have very strong claws suitable for gripping trees and climbing. Between their first and second "fingers" is a large gap, which enables them to also grip tree branches comfortably, whilst their hind legs have one toe set at a wide angle. They also have toes with thick pads which enable them to sit comfortably in a tree all day.
In order to attract a mate, the male has a scent gland which emits a very strong scent. He also makes unusually loud grunting noises.
As with most marsupials, the koala has a pouch, where the joey stays after birth for up to ten months. When the joey leaves the pouch, it stays for several more months on the back of their mother. The pouch opens backwards. After about 30 weeks, the mother produces a substance called pap. This substance is actually a specialized form of the mother's droppings which, having passed through her digestive system, give the joey the enzymes it needs to be able to start digesting the tough gum leaves, making an easier transition for the baby koala to start eating eucalyptus leaves.
Koalas in southern regions have thick, wool-like waterproof fur to keep them warm in cold weather and dry in rain. Koalas in northern regions are smaller, with less dense fur.
Koalas are not solitary animals, but actually live in communities where the social structure is quite complex. Koalas are territorial, but each koala within the social group has its own specific range for feeding, which may or may not overlap the range of its neighbor. There is always one dominant male in each social group, but he is by no means the only male. Koalas feed alone and travel alone, but they understand their own social structure. When one of their community dies, another does not immediately move in and take its place. It takes about a year for the scent of the previous occupant to fade, and only then will another koala move in to its range.