What are the koala's adaptations for its habitat?

Koalas live in eucalyptus trees and eat only a few types of gum leaves from which they get all nutrients and water requirements. Eucalyptus leaves are tough, toxic and low in nutrition, but the koala has developed a stomach which is capable of removing the toxins from where they are filtered out by the liver. The caecum completes the process by changing the eucalyptus leaves into digestible nutrients. The caecum is similar to the human appendix.

Koalas must eat over a kilogram of leaves per day to meet their energy requirements. Eucalyptus leaves contain approximately 50% water, 18% fibre, 13% tannins, 8% fat, 5% carbohydrates, 4% protein and 2% minerals. Koalas have been seen in 120 kinds of eucalypt tree including Manna Gum, Swamp Gum, Blue Gum, Forest Red Gum and Grey Gum. However, they are only able to eat from some 60 species of gum trees, and within these sixty, there are just a dozen that they actually prefer above others.

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.

As with all 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 specialised 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.