Koalas look like bears, but they are not bears. They are marsupials, like the kangaroos and wallabies and about 200 other Australian animals.
Koalas grow to about 9 kilograms in weight - males up to 14 kg and females up to 11 kg. They tend to be heavier in the cooler southern states like Victoria, and lighter in Queensland.
The name 'Koala' comes from an aboriginal word meaning 'no drink'. They get almost all of their water requirements from the leaves they eat. They eat mainly eucalyptus leaves, also known as gum leaves. These leaves are poisonous to most animals, and they don't have a lot of nutrition. To enable them to survive on this diet, koalas were created with a very slow metabolic rate, which means they can keep their food in their system for a long time so they can extract the maximum energy value from it. This means that they also need less energy to operate and can sleep for up to 18 hours per day.
Koalas are very social creatures. They live in communities in forested areas where there is a good food source. They have their own territory, but it overlaps the territory of other koalas. It is in these areas of overlap that they interact with other koalas.
Koalas communicate using bellows to state their social position, and also their physical location. Both males and females do this, but the males more so. Mothers and babies communicate by soft clickings and humming. When koalas are frightened they scream.
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