Female koala (Phascolarctos cinereus) with her joey, at Warrnambool, Victoria, Australia. The animals are at rest on a Eucalyptus bough, about 4 metres above ground level. The joey is independent of its mother's pouch, but not yet mature enough to be free living. Koalas are arboreal marsupials. They are asocial animals that spend most of their time as solitary individuals, unless during the breeding season, or, as here, when raising young. When the joey is mature enough to fend for itself, it will be rejected by its mother. Koalas have one of the smallest brains relative to body size of any mammal. They spend up to 20 hrs a day asleep, and their diet consists of leaves of a variety of eucalyptus leaves, of low nutritional value. Koalas are listed as vulnerable by the IUCN. Formerly hunted for their fur, they are now threatened by koala retrovirus and Chlamydia bacteria. |