Koala is the only mammal, other than the Greater Glider and Ringtail Possum, which can survive on a diet of eucalyptus leaves.
Koala seldom drinks water obtaining it from the eucalyptus leaves, which are 50% consisting of water. Although, they can drink water if due to drought the leaves water content is reduced.
Koalas consume eucalyptus leaves and bark from 12 different eucalyptus tree species. They also consume mistletoe and box leaves.
Koala in Victoria would have different diet from koala in Queensland as different species of eucalypts grow in different parts of Australia.
Sometimes koalas eat leaves from other trees such as wattle tree, tea tree, paperbark tree.
Each koala eats approximately 200 to 500 grams of leaves per day.
Koalas have a slow metabolic rate due to their high-fiber, low nutrient diet. Because they store little or no fat, koalas must adopt strategies that conserve energy. Sleeping is one of them.
Koalas sleep for up to 16 hours per day in order to conserve energy.
A very slow metabolic rate optimizes its energy requirements and allows koalas to retain food within their digestive system for a relatively long period of time, maximizing the amount of extracted energy.