Stress-related disease killing off Australia's koalas

The koala, Australia's star symbol, is dying of stress.

Koalas live in the rolling hills and flat plains where eucalyptus trees grow, because they need the leaves for both food and water. But as people move in, koalas are finding themselves with fewer trees, researchers say. The stress is bringing out a latent disease that infects 50 to 90 percent of the animals.

"Koalas are in diabolical trouble," says researcher Frank Carrick, who heads the Koala Study Program at the University of Queensland. "Numbers show that even in their stronghold, koala numbers are declining alarmingly."

The problem came to national attention in August, when the well-known Sam the Koala died during surgery to treat the disease, called chlamydia. Sam captured the world's attention during major wildfires in February, when she was photographed drinking from the water bottle of a firefighter in a smoldering forest.

Sam was in such obvious pain from chlamydia that veterinarian John Butler decided to operate. But her organs were too scarred to complete the surgery, and Sam was euthanized.

Chlamydiosis is a virus that breaks out in koalas in times of stress - like cold sores in humans - and leads to infections in the eyes and urinary, reproductive and respiratory tracts. It can cause blindness, infertility and death.

Deborah Tabart, chief executive of the Australian Koala Foundation, urged the government to follow up on Sam's case by classifying koalas as a threatened species and implementing policies to preserve their habitat. Her organization named September "Save the Koala" month, with the theme "No Tree, No Me."

The United States already considers the koala a threatened species. And the Australian Koala Foundation estimates there are fewer than 100,000 koalas left in Australia, down from the millions at the time European settlement started in the late 1700s.

Carrick and other scientists think the numbers are slightly higher, but in any case, regional counts by scientists and state governments show a huge drop. There's clear evidence that some local populations have gone extinct because of chlamydial disease, Carrick said.

The majority of koalas hug a stretch of eastern coastline in the states of Queensland and New South Wales. They are most abundant on the so-called Koala Coast, a 155 square-mile (375 square-kilometer) swath of semi-rural coast in southeastern Queensland.

A 2008 survey of the Koala Coast by the Queensland government shows the population dropped 64 percent, from more than 6,200 in 1999 to about 2,800. While car accidents and dog attacks killed many koalas, the report blamed about 60 percent of the deaths on disease.

"We need to learn to live with our native species but instead we keep encroaching on them," said Tracy Goodman, an Adelaide resident who recently visited Gorge Wildlife Park with her husband and 4-year-old son, Matthew. Ten koalas live at the park. "Protection of koalas absolutely should be legislated."

Wide-eyed children waited in line to hold and pet Violet, a tame koala patiently munching on moist eucalyptus leaves. "They are quite cuddly and soft, aren't they?" 7-year-old Emily Marshall grinned after her grandparents took her photo with Violet.

Wildlife keeper Loren Ellis said all of Gorge's koalas are healthy, though she's not sure about the wild ones who visit occasionally, searching for food.

"There aren't always enough leaves to go around in the wild," Ellis said.

Australia, known for its unique flora and fauna, already counts more than 55 extinct mammals, birds and reptiles.

In 2006, the government's Threatened Species Committee said local population declines did not necessarily mean koalas were declining across the whole country and that they were "resilient" enough to live in small or fragmented habitats. But Environment Minister Peter Garrett has since ordered a review of the government's conservation strategy.

"I have agreed that the situation probably has changed; it looks like the figures for koalas aren't as good as I would like," Garrett said in a television interview last month.

The two states with the densest koala habitat have taken measures to protect the animal. New South Wales has classified them as a vulnerable species under the state conservation act, and endangered in two areas. Queensland lists the animal as vulnerable in some parts of the state.

While applauding the state efforts, Carrick urged the federal government to get involved.

"If koalas are not of national significance, I don't know what on earth would be," he said. "Koalas are right up there as an international wildlife icon with China's pandas."

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On the Web:

Australian Koala Foundation: http://www.savethekoala.com

Australian threatened species: http://www.environment.gov.au/biodiversity/threatened/species.html