Koalas Put on Birth Control Drug

Rangers in western Victoria's Mount Eccles national park are beginning a programme to put contraceptive implants into 3,000 koalas that are eating themselves out of house and home in the park.

The animals, which feed almost entirely on eucalyptus leaves, have eaten half the canopy cover in seven out of ten Mount Eccles trees and could face starvation if their breeding is not slowed.

The new programme uses contraceptive hormones similar to those used by women. Park keepers will catch the koalas and insert hormone implants under the skin over the next few years.

"If we don't do something there could be a mass death of trees, and that will lead to a mass death of koalas," said Sally Troy, research manager for Parks Victoria.

Females produce up to 10 offspring. Their predators were once dingoes and humans, but the wild dogs have been driven out of south-eastern Australia by sheep and Aborigines have long since stopped hunting them.