Koala

Gestation / Life Span Koalas have a gestation period of 34-36 days. Lifespan varies considerably due to their local environment. They can live for 15 years, although most survive for only 3-4 years.

Habitat Koalas generally inhabit woodland habitats across Australia.

Common Predators Domestic dogs and dingoes. Young may be taken by owls and wedge-tail eagles. The biggest threat is clearing of land resulting in loss of habitat and food supply.

What Is a Koala?

Whilst the Koala is bear-like, it is not related to any of the bear species found around the world. The Koala's closest relatives are Australia's own wombats. The Koala is a marsupial mammal which means the female Koala carries the young in a pouch. The Koala is named from an ancient Aboriginal word meaning “no drink” as it receives over 90% of its water from eucalyptus leaves. Koalas only drink when they are sick or at times of drought when there is insufficient moisture in eucalyptus leaves.

The Koala has a broad, flat head with large round hairy ears, a flat nose, a short, stocky body, short legs and large feet with very sharp claws. They are covered in thick ash-grey fur with white on their chest, forelimbs and rump. Koalas inhabiting the southern parts of Australia have a thicker coat.

Males are larger than females and koalas inhabiting the southern parts of Australia are larger than those living in the north. Males weigh 6.5 – 11.8 kilograms and females 5.1 – 7.9 kilograms. They are approximately 72 – 78 centimetres in length. Their bodies are well rounded due to the capacity of their large intestines required to digest eucalyptus leaves.

Koalas spend 20+ hours each day sleeping and resting due to the low amount of energy they obtain from their leafy diet. They are generally more active at night and communicate using loud grunts and squeals.

Where Does a Koala Live?

Koalas inhabit forest from south-eastern South Australia up to Queensland. They are generally found in open eucalypt forests. Within the inland part of their range koalas tend to live in trees surrounding watercourses. During the warm part of the day they will often rest in a fork of a shady tree. In cold and wet weather they may retreat to the thick foliage of low trees for protection.

What Does a Koala Eat?

Koalas are called fussy eaters as they feed almost entirely on only 50 of the 500+ available species of eucalypt leaves. An adult Koala will eat up to 1 kilogram of leaves each night. At certain times of the year some eucalyptus leaves can be poisonous and it is thought Koalas select suitable leaves by sniffing them first. Different species of eucalypts grow in different parts of Australia, so a koala in Victoria would have a very different diet from one in Queensland. In Victoria, the koala feeds primarily on species such as; Manna Gum ( Eucalyptus viminalis) , Messmate ( Eucalyptus obliqua), Brown Stringybark ( Eucalyptus baxteri) and Swamp Gum ( Eucalyptus ovata).

A Koala's Family Life

Female koalas become sexually mature at 2 years of age and males mature at 3-4 years.

Spring is the peak breeding season. During this time young from the previous year are being weaned by their mothers and male koalas bellow loudly to attract a mate.

36 days after mating the female gives birth to a joey. The joey looks much like a pink jellybean as it is only 2cm long, totally hairless and blind. It makes its way from the birth canal to the pouch completely on its own, relying on its already well developed senses of smell and touch. The joey has strong forelimbs and claws to help it through its mother's furred pouch. Once inside the pouch it attaches itself to one of the two teats which swells to fill its mouth, preventing the joey from being dislodged from its food source. Female koalas have a backwards facing pouch which contracts strong sphincter muscles at the pouch opening to prevent the joey from falling out.

The joey stays in the pouch for 7 months, drinking only its mother's milk. It then graduates to riding on its mother's back and feeding on ‘pap', which the mother produces in addition to milk, and eventually adds eucalyptus leaves to its diet. Pap is a soft form of faeces which is fed to the joey to provide it with the micro-organisms it needs to breakdown eucalypt leaves once it leaves the pouch. The joey is weaned at 12 months and the mother is able to mate again.

Young female Koalas usually stay in the vicinity of their mothers for a second year and some may establish a home range nearby. Males disperse from their mothers' range when they are 2 years old and may roam for 2-3 years before establishing a territory. Koalas are generally solitary animals, although they live in communities.

Whilst dogs and dingoes are threats to adult Koalas, joeys are more likely to fall prey to owls or eagles. Overall, the major threat to our Koala populations is land clearing and fatalities that occur from Koalas crossing roads to reach food trees.

Want to Know More?

http://www.nationalparks.nsw.gov.au (click on native plant and animal fact sheets / koala)