KOALA (Phascolarctos cinereus)

The Koala is a marsupial mammal. This means it has a pouch in which to carry her young. It is not a bear, it is not related to the bear.

DESCRIPTION:

The koala has a large round head, large round furry ears, a stout body. It has long arms with powerful claws. The first two fingers on its paws are both like thumbs, with strong nails that wrap around the branches to give it a firm grip. It has short legs and large feet.

The koala has a large round head, large round furry ears, a stout body. It has long arms with powerful claws. The koala is a very good tree-climber, though slow and clumsy on the ground.

It is covered in thick ash-grey fur, with white on their chests, inner arms, and ears. They have a stub tail and the fur on its bottom is densely packed to provide comfort when sitting on hard branches. This fur has a 'speckled' appearance which makes koalas hard to spot from the ground.

Their bodies are very rounded due to their very large intestines which are needed to digest eucalyptus leaves. Due to the low amount of energy that koalas obtain from their leafy diet they spend twenty hours of the day, or more, sleeping or resting in gum trees, the remainder of the time is spent feeding, moving around, grooming and social interaction. Koalas are mainly active during the night, at dawn and dusk. They use loud grunts and squeals to communicate.

On hot days they can be seen with their limbs dangling in an effort to keep cool, and during colder times, curled up in a ball to conserve body heat.

They grow to a length of 60-85 cm.

The male weighs up to 13.5 kg, the female up to 7.9kg.

The koala is more closely related to the wombat than to any other living marsupial, but the relationship is not close.

Koalas rub their chests against trees to mark their territory.

They are docile animals except when teased or frightened.

The life-span of a wild koala is approximately 10-12 years, with koalas in captivity reaching ages of 15 to 18 years.

Whilst the koala is an excellent swimmer, this is not a regular occurrence. They are able to cross rivers to escape from heavy flooding.

They occasionally jump from one tree to the next.

HABITAT AND DISTRIBUTION:

The koala is found in open eucalypt forests and lightly wooded regions from south-east Queensland to south-east South Australia. Because their food is restricted to the leaves of certain eucalypts, they live almost exclusively in the highest branches of these trees.

DIET:

The diet of a koala is restricted to eucalypt leaves. It has developed cheek pouches for storing food and a digestive system able to deal with unpalatable, and even toxic compounds in eucalypt leaves. An adult koala eats an average 500g to 1kg of leaves and young shoots a day. Koalas can not eat all eucalypt species, only 50 of the 500 or more species are suitable to the koala's diet. Koala are able to sniff leaves to see if they are suitable to eat.

Koalas seldom drink as they obtain enough water from their leafy diet and the dew they find on leaves in the morning. 'Koala' is an Aboriginal word meaning 'no water'.

Koalas also eat a small amount of soil to supplement their diet with mineral nutrients.

The main problem with keeping koalas in sanctuaries or zoos outside Australia is getting enough leaves of the right species of eucalypt.

BREEDING:

Koalas normally breed only once every two years.

Females generally start breeding at about three or four years of age and usually produce only one offspring each year. However, due to age and quality of habitat not all females in the wild will breed each year. Some produce offspring only every two or three years.

The breeding season is during spring and summer (September to March). During this time the male koala calls loudly to attract a mate.

About 35 days after mating the baby, called a joey, is born. It is only 2cm long, blind, naked, and earless. Relying on its already well-developed senses of smell and touch, it makes its way, unaided, up through the fur from the external opening of the birth canal to the pouch. The mother has a backwards facing (or upside down) pouch.

Once inside the pouch, the young koala attaches itself to one of its mother's two nipples, which swells to fill its mouth. This prevents the joey from being dislodged from its source of food. The mother contracts her strong sphincter muscles at the pouch opening to prevent the baby from falling out.

From about 22 to 30 weeks, it begins to feed upon a substance called "pap" which the mother produces in addition to milk. Pap is a specialised form of faeces, or droppings, which forms an important part of the young koala's diet, allowing it to make the transition from milk to eucalypt leaves. Pap is soft and runny and thought to come from the caecum. It allows the mother to pass on micro-organisms present in her own digestive system which are essential to the digestion of eucalyptus leaves, and is a rich source of protein.

The joey remains in the mother's pouch for the first seven months. It begins to leave the pouch when it is lightly furred and is four to five months old, returning periodically until about six months old.

It is carried on the female's back until it is about twelve months old.

By 18 to 24 months of age the joey is independent and looking for its own home.

The young koala has a growth period lasting for a total of about four years and is sexually mature when three to four years old.

THREATS:

The greatest threat facing wild koala populations today is destruction and fragmentation of habitat and have resulted in crowding of the surviving koalas into smaller areas, and increased exposure to the dangers of road traffic and domestic dogs.

The koala's main predators are dogs, foxes and dingoes. Other animals posing a threat also include goannas and pythons. All of these are most likely to prey on young koalas. To escape they will attempt to climb trees or scratch with their sharp claws. The young may also be taken by powerful owl or other large birds of prey.

A mating disease called Chlamydia affects the reproductive system of some koalas in certain areas.

Bushfires and droughts also affect the koala's habitat and food supply and can threaten the koala's survival.

There is also risk of injury or death from cars.

Visit the Australian Koala Foundation site for more information about the koala and its conservation.

Back to Australian Fauna page.