Class: Mammalia
Lifespan: Up to 15 years
Diet: Herbivore
Weight: Up to 15kg
Height: Up to 82cm
Speed: Up to 30km/h
Reproduction: Live birth
Status: Vulnerable
Although a common misconception, koalas are not bears. Koalas are marsupials, meaning they have a pouch and give birth to under-developed young, known as joeys. A koala’s gestation period is 33-35 days, before they give birth to a tiny pink, hairless joey weighing about one gram. The jelly-bean like joey will immediately climb in to its mother’s pouch, where it will attach to a teat to drink milk and stay for approximately six months.
At six months of age, the joey (now fully-furred) will emerge from the pouch to start exploring the world and gradually learn to eat eucalyptus leaves. At 12 months of age, the joey will be completely weaned and is independent from mum.
Koalas have a specialised diet of eucalyptus leaves, eating approximately 50 of the 800 species that grow in Australia. Koalas have special bacteria in their gut to help them digest the otherwise toxic leaves. Eucalyptus is low in nutrition, so koalas sleep and rest 18-20 hours a day to conserve energy. They are not ‘drunk’ or ‘drugged’ by the leaf. Although low in nutrition, the leaves do have high water content, so koalas rarely need to drink from alternate water sources. One koala will consume up to 500 grams of leaf per day.
Koala hands and feet have long sharp claws, and thick pads for cushioning. With three fingers and two opposable thumbs on their front paws, that have fantastic grip for climbing. They have a grooming claw on their hind paws, created by the first and second toes being fused together. This claw is used like a comb to groom themselves and remove old fur. Koalas have thick fur on their bottoms, which acts like a cushion between them and the tree branch. Their bottoms are also made of bony cartilage, to make sitting on branches as comfortable as possible. Koalas have white speckles or spots on their bottoms, which act as camouflage when up in the tree, making it hard for predators, like goannas, to spot koalas from the ground. Each koala’s spots are unique, also making it one way we can tell our koalas apart.
Koalas also have fingerprints, just like us humans. Each koala’s prints are completely unique.
Male koalas are easily identified by brown scent glands located on the white of their chest. Females have clean, unmarked white chests. The scent glands of males have a very distinguishable smell. They rub this scent on the base of trees in their territory, as well as on the trunk as they climb, to mark the location as theirs. The scents also attract females during breeding season.
Koalas communicate by making a deep growling or grunting noise known as a ‘bellow’. This sound is used by males to attract females during breeding season, and intimidate other males in the area. Females may also bellow when they are in season to let any males know of their whereabouts, but this behaviour is less common. A koala’s bellow can be heard up to 800 metres away.
As the human population grows, koala habitat is shrinking and becoming fragmented by housing and roads. This urbanisation increases the risk of car strikes and dog attacks to koalas, as they try to move between pockets of habitat. Loss of habitat also means a decreasing food source for koalas, as well an increase in competition for territory and breeding partners.
Lone Pine is proud to have been home to the amazing Sarah, who for some years, held the record for the world’s oldest captive koala. She lived to the amazing age of 23 years!