The koala is a marsupial, as are kangaroos, opossums, and their closest relatives, the wombats. After a very short gestation, marsupials give birth to embryonic or premature babies that are roughly the size of a jellybean. A koala baby, called a joey, is born after about 35 days. Hairless and blind, a joey uses its sense of smell and strong front legs with claws to climb up its mother’s fur into her downward-facing pouch. In the pouch the joey attaches to a teat to nurse and continues developing for the next six months.
A joey’s first solid food is poop called “pap,” a specialized form of the mother’s feces that is soft and runny. Pap provides the youngster with the digestive bacteria needed to tolerate a diet of eucalyptus leaves, which are toxic for most other mammals. At about six months of age, a joey begins emerging from the pouch to ride on its mother’s back. Adult koalas are largely solitary but do have overlapping ranges. Powerful legs and sharp claws are used for climbing trees. A thick pad of fur on their hind ends acts as a portable cushion for sitting comfortably in branches. Koalas come to ground only to move between trees. Of the 700 species of eucalyptus found in Australia, koalas eat the leaves of fewer than thirty. They consume 1 to 2 pounds a day, picking out young leaves and shoots. Due to this toxic, low-nutrient diet, they sleep between 18 and 20 hours a day to conserve energy. Koala populations continue to decline. In the late 1920s the Australian government enacted a nationwide ban on hunting of these iconic marsupials for their fur. Today, habitat fragmentation and loss due to logging, brushfires, and drought resulting from climate change are the greatest threats.
At one time, koalas faced the threat of extinction by fur hunters. Thankfully, in the late 1920s, the Australian government instated a nationwide ban on the killing of these docile marsupials. Listed as vulnerable by the International Union for Conservation of Nature (IUCN), the koala population still faces obstacles that are diminishing their numbers. Over-browsed forests, brushfires, drought, infection, disease, urban encroachment, and even motorists threaten the koala population.
Wild koalas are found only in Australia. They live in fragmented eucalyptus forests on the eastern and southern coasts and inland areas of Queensland, New South Wales, Victoria, and South Australia.
A koala’s diet consists almost entirely of eucalyptus leaves.
Koalas grow 2 to 3 feet long and weigh 10 to 25 pounds. Males are 50 percent larger than females. Their lifespan in the wild averages 12 to 15 years. In human care, koalas can live up to 20 years.