1 Koalas can only be found in the eucalyptus forests of eastern and south-eastern Australia. 2  Their habitat quality can be measured by density of the food trees. 3  Koalas do not live in the rainforest.4  There are only 2,000 to 8,000 wild koalas in Australia at present. Koalas do not live in the rainforest. 2  There are only 2,000 to 8,000 wild koalas in Australia at present. 3  They can live to be 17 years old in the wild, but if they live near populated areas they usually have a shorter life-span because of accidents and disease.