Koalas Dying, and Scientists Don’t Know Why

Cuddly koalas trying to survive in shrinking bush lands are dying at an alarming rate--and scientists don’t know why.

With the furry, tree-living marsupial extinct in South Australia, researchers are desperately trying to unravel a mystery threatening the koala’s survival in the wild along Australia’s east coast.

Specialists suspect that the villain is man, who is destroying the natural habitat of the big-eyed animals that rival kangaroos as Australia’s national symbol.

While pictures of the soulful koalas lure tourists and spur sales of Australian products, little is known about it.

“Ignorance is the biggest problem facing Australia’s koala population--ignorance of their health problems, their mortality rate and how they are adapting to the changing environment through contact with humans,” says Paul Canfield, senior lecturer in the Department of Pathology at Sydney University.

Cause Eludes Researchers

After carrying out post-mortems on 160 koalas, Canfield--one of the few academics actively involved in koala research--found that one out of every five died without any apparent cause.

“In 20% of the cases we can’t find any tissue damage in the dead koalas. There are no specific lesions. We just don’t have adequate information, so it is impossible to reach a diagnosis.”

Many of the koalas Canfield examines are killed by cars, or mauled by other wild animals or even pets such as dogs. But the deaths baffling veterinarians involve koalas ranging in age from 2 to 7 with general signs of debilitation such as lackluster coats and inadequate fat reserves--but no diagnostic ailment.

While urogenital disease is believed to be interfering with the koalas fertility, Canfield contends that stress is taking a severe toll and may account for the large number of unexplained deaths.

Once numbering in the hundreds of thousands, the koala, often mistakenly referred to as a bear, thrived in the forest areas of eastern Australia, feeding primarily at night on eucalyptus leaves.

In the early part of the 20th Century the koala was slaughtered for its soft gray fur, but it has been protected for more than 50 years. But the environment the koala depends upon has not had the same protection. The trees they rely on for shelter and food are continually cleared for more housing and shopping developments.

Many Obstacles

Forced to travel longer distances for food and shelter, “they find all kinds of obstacles in their paths, such as roads, cars, fences, pets, dangerous chemicals and swimming pools,” Canfield said.

Agile in trees but slow moving on the ground, getting from one tree to another is a perilous venture, Canfield said. “Koalas have adapted as much as they can to man,” he said. “It is now up to man to make some adaptation for the koala.”

Little is known about how to treat sick koalas, and treatments that work with domestic animals have limited success. “If we can work out disease patterns we can start working out treatments,” Canfield said. “Most treatment now is symptomatic, but we would like to treat the causes.”

Studies of koalas have been hampered by limited government funding and few veterinarians concentrating on research. But Canfield said that is changing with increased interest from researchers from the United States and other nations.

Establishing their numbers is a No. 1 priority. Traditional methods of counting such as air spotting don’t work with koalas, who are well camouflaged clinging to the tree branches.

Volunteers Aid Effort

Biologist Philip Reed, charged with counting koalas and determining their areas of concentration for the New South Wales Wildlife Service, asked schoolchildren, farmers, bush walkers, railroad employees, electricity workers and residents to report koala sightings.

While Reed has not determined a number yet, he has found koalas concentrated in patches, primarily on the north central coast of New South Wales.

“They’re not very abundant in any one locality,” Reed said. “The biggest problem is their very specific requirements. If we don’t maintain the areas that are left for them, their longtime survival is at stake. What I’m worried about is what happens in the next 200 years.

“Koalas and people just don’t mix well,” Reed says. “Koalas are just coming to grief against haphazard development.”

But raising the level of public awareness is helping, Reed notes. “People are turned on by koalas. Many put ropes into swimming pools once they learned koalas can swim but can’t climb out of the pools if they fall in.”

Koala Preservation Society members have treated hundreds of injured animals. They even learned how to hand-rear cubs to become independent so they can be released back into the wild.

And conservationists are seeking a ban on the export of koalas and the repatriation of those abroad after the deaths of several in zoos overseas.