Koala

Koala: Phascolarctos cinereus

Distribution: East Australia

Habitat: Dry forest

Size: These measurements are the average for koalas in the South of their range; the ones in the North are quite a lot smaller. Head - body length: Male - 78 cm Female - 72 cm Weight: Male - 12kg Female - 8 kg

Gestation: 34 - 36 days

Life Span: Up to 13 years (18 years in captivity)

The koala is perhaps the best-loved of all Australia's marsupial, or pouched, mammals. Although it
is rather bear-like in appearance, its nearest relatives are the opossums. Tailless, except for a very short stump, the koala has thick ash-grey fur, tinged with brown on the upper parts and it is white on the under parts.

A Tree-Top Life, The koala spends most of its time shuffling around the topmost branches of Eucalyptus, or 'gum' trees, hanging on tight with its four grasping feet. It sleeps during the day, curled up in a tree-fork and feeds at night on the leaves and shoots of a few species of Eucalyptus. An adult will eat about 500g of leaves a day. The name koala means 'no drink' and it rarely does so. It occasionally comes down to the ground, either to eat soil, which is thought to aid digestion, or to move to another tree.

Breeding. During the summer, a male koala collects a small harem of females and guards them closely from rivals. After a gestation period of 34-36 days, there is normally only one baby born. It measures only 2cm in length and weighs a mere 0.5g. The tiny creature climbs into its mother's backward opening pouch (other way round to a kangaroo's pouch) and stays there for 5 or 6 months, feeding on milk. After it leaves the pouch, it rides 'piggy-back' on its mother for another 6 months, and to begin with, she feeds it on partially digested food that has passed through her digestion system. The young one is independent by 11 months of age and it may live close to the mother for a few more months.

From Persecution to Protection. In the early years of this century there were millions of koalas. Now there are thousands. The decline in numbers began in 1887 when for two years, and again in 1900 for three years, disease killed many. Also at that time, a favourite 'sport' was to shoot koalas as they sat in their tree-tops. Over the years, koalas have been killed by forest fires and their habitat destroyed to make way for agriculture and towns. There used to be a market for their thick, beautiful fur. In 1924 over 2 million koala pelts were exported. Fortunately, the public began to object strongly to this ruthless slaughter and sanctuaries were set up for them. Koalas are now fully protected and are in no immediate danger of extinction.

Koalas in Captivity. Few of us are fortunate enough to visit Australia and see a live koala. In the past it has been difficult for zoos outside Australia to keep koalas because of their specialized diet. However, our knowledge of the koala's needs is much greater nowadays and koalas may be kept successfully in captivity worldwide.

In July 1989, two female koalas arrived at London Zoo, from San Diego Zoo, and settled happily, living on a diet of up to 6 species of eucalyptus, some of which were flown in specially from Australia and others sent up from Devon. Sadly, one of the koalas became ill in 1992 and died. The Zoo considered it unfair to keep the remaining koala on her own so she was sent away to join a group living in a zoo in Portugal.

Zoos such as London Zoo are keen to establish breeding groups of endangered animals in captivity; this may be the only way to save some species from total extinction should they disappear from the wild. Provided their natural habitats are still suitable, it is possible to introduce captive-bred animals back into the wild. This has already been quite successful with the golden-lion tamarin in Brazil and the otter in Britain.

At the moment it is not possible to see koalas in Britain but perhaps a breeding group will be established here sometime in the future.