Scientific American (February '95)

T he bushfires that raged in the past year or so during one of the worst dry spells in recent Australian history destroyed scores of houses. They also consumed trees that are home to animals that have helped sell airplane tickets to tourists visiting this island continent. The blazes put an additional strain on diminishing koala habitat: the land where these creatures live in eastern Australia is increasingly being sought by real-estate developers.

Koalas have come to live cheek-by-snout with people moving into coastal areas populated with the animals' prized food. Koalas prefer to eat the leaves of less than a dozen of the 650 native varieties of eucalyptus trees. Undeniably, the past 100 years have not been good to this marsupial (koalas are bears only in their resemblance to the genus Teddy). Millions of pelts went to England around the turn of the century as a sought-after, cheap and durable fur.

Despite mounting threats, it is unclear just how endangered this age-old creature is. The koala - which plays a critical role in the Dreamtime, the Aboriginal myth of the creation of the world - has a reclusive nature, so it is difficult to perform an accurate census. Although estimated by the Australian Koala Foundation (AKF) suggest that its numbers have dropped from 400,000 in the mid-1980s to between 40,000 and 80,000 today, no one really knows how many koalas remain.

Notwithstanding concerns voiced by a few activist groups, the Australian government has not put the koala on its endangered list, which comprises 75 vertebrates and 223 vascular plants. The state government in New South Wales, with its abundance of vacation and retiree homes, has designated the koala "vulnerable," a notch below endangered. Yet park officials have had to move koalas from several islands off the coast in the state of Victoria because of the marsupial's overpopulation, says Jim Crennan of the Australian Nature Conservation Agency.

The federal government in Canberra has actually tried to generate interest in species it considers to be more threatened. But "the koala is a national icon," notes Crennan to explain why there is more popular attention devoted to it than to an endangered species such as the Northern Hairy-Nosed Wombat. The government also supported a campaign to substitute a chocolate Easter bunny with a chocolate bilby. (The rabbit-eared bilbies are threatened, whereas rabbits are considered a serious pest.)

The state governments do maintain some wildlife management programs for the koala; the federal government places tight restrictions on exports to foreign zoos, and a number of university research programs exist. But perhaps because of the cute-and-cuddly factor, a great deal of research and care for the koala occurs at the grassroots level. One notable example is the privately run Koala Hospital located in the New South Wales town of Port Macquarie, 300 miles to the north of the city of Sydney.

The hospital, founded 21 years ago by two shopkeepers and a local newspaperman, provided assistance to some 250 koalas last year, a figure that rose dramatically with the fires. The average number of patients seen by the hospital is usually closer to 170 - most frequently the result of car accidents, dog attacks and bacterial diseases such as Chlamydia. The hospital survives largely on volunteer labor. (Twenty percent of the AUS$70,000 a year in expenditures needed to run the facility are from interest on royalties for a song about koalas, "Goodbye Blinky Bill," written by Australian singer John Willianson.)

Another approach to saving koalas is more conceptual. The AKF has a database that combines on-site surveys and satellite data into a Koala Habitat Atlas. It has begun to provide both a census and an assessment of how much koala living space has been lost. "It's not how many animals are left - it's how many trees are left and how many trees can be sustained," says Deborah Tabart, the AKF's executive director.

This information can be employed to divert builders away from stands of eucalyptus. It may also give the AKF or another group enough data to apply to the government to have the koala listed as an endangered species. Unfortunately, the atlas, the compilation of which began in 1990, can also be used by real-estate developers seeking untouched areas, Tabart says.

Koalas, which have low fecundity, are not particularly well adapted to survive the destruction of their arboreal homes or to live near people. Having abnormally small adrenal glands in relation to body weight, the animal do not cope well with stress, states Ken Phillips, a volunteer researcher at the Koala Hospital who is also a professor of psychology and telecommunications at New York University. The nocturnal creature is easily blinded by car lights, writes Phillips in a recent book, Koala: Australia's Ancient Ones. And despite long teeth and claws, which could make them a worthy adversary, they are slow, lumbering and easily upset. Koalas do not fight back when a dog attacks.

Most Australians have never seen a live koala in the wild. If human incursions continue unabated into stands of eucalyptus, Phillips notes, they may never see one. Aboriginal mythology holds that koalas, when abused, have powers that can induce drought. The story seems to have a strange-parallel in fact. Australia has experienced a severe drought, and in places such as Port Macquarie, the koala has definitely had its placid existence disrupted.