Extreme drought, ferocious bushfires and urban development are killing Australia’s koalas and could push the species towards extinction within a decade, environmentalists are warning.
Alarms about the demise of the iconic and peculiar animal, which sleeps about 20 hours per day and eats only the leaves of the eucalyptus tree, have been raised before.
But Deborah Tabart, CEO of the Australia Koala Foundation, believes the animal’s plight is as bad as she has seen it in her 20 years as a koala advocate.
“In south-east Queensland, we had them listed as a vulnerable species which could go to extinction within 10 years. That could now be seven years,” she said. “The koala’s future is obviously bleak.”
South-eastern Queensland has the strongest koala populations in the vast country, meaning extinction in this area spells disaster for the future of the species, said Tabart.
The biggest threat is the loss of habitat due to road building and development on Australia’s eastern coast — traditional koala country. The joke, said Tabart, is that koalas enjoy good real estate and are often pushed out of their habitat by farming or development.
“I’ve driven pretty much the whole country and I just see environmental vandalism and destruction everywhere I go,” she said. “It’s a very sorry tale. There are [koala] management problems all over the country.”
Massive bushfires that raged in the country’s south for weeks during the Australian summer, burning a million hectares of land, would also have killed thousands of koalas.
Meanwhile, there is the worst drought in a century, genetic mutations from decades of inbreeding in some populations, and the widespread incidence of chlamydia, a type of venereal disease that affects fertility, to further cut koala numbers.
Moreover, the animals are often fatally attacked by pet dogs. “In south-east Queensland, the koalas are just in people’s backyards and the dogs just munch on them,” Tabart said.
Koala numbers
Confusing the issue is the lack of data on the number of koalas in the wild. Figures range from 100 000 animals to several million. What is known is that there were once millions of them ranged along eastern Australia.
The hunting and slaughter for their furs in the 1920s eradicated the species in the state of South Australia and pushed Victorian populations close to extinction.
Public outrage over the killing of the big-eyed “bears” put an end to the practice, but Victorian stocks were unfortunately later replenished with in-bred animals, leading to a lack of genetic diversity in that state.
As a result, genetic problems such as missing testicles and deformed “pin” heads emerged in Victorian koalas, said University of Queensland academic Frank Carrick.
Carrick, who leads a koala study project at the university, estimates the national population of the marsupial at about one million. And while he doesn’t believe the animal will be extinct within a decade, he acknowledges that numbers are contracting.
“Though we don’t really have an accurate figure on how many koalas there are in Australia right now, we do know one thing — that it’s going down. Because we keep chopping down trees and their food source,” he said.
Carrick said it will take 40 to 50 years for the koala to recover sufficiently from the effects of the latest Victorian bushfires, drought and development.
“Exactly how small do we want the population to be before we push the panic button?” he said.
Territory
Dan Lunney, a senior research scientist with the New South Wales state department of environment and conservation, said koalas cover roughly the same territory as they did 20 years ago.
In some areas — Victoria state and Kangaroo Island in South Australia — koala numbers are growing. But in New South Wales (NSW), which tracks the east coast of Australia, the koala is a recognised threatened species.
“That means if nothing is done about it the population will continue to decline,” he said. “The issue is not how many there are; it’s whether they are declining or not.”
Lunney said while the Victorian bushfires would have killed large numbers of animals, as long as some koalas survived and as long as sufficient bush regrowth is maintained, the population will recover overall. “Koalas can take a fair bit. That’s why we’ve still got them,” he said. “But they do have a threshold at which they can’t continue.”
He said populations are at most risk of dying out in areas where new houses are being built, putting them at risk of death by cars and dogs.
“Koalas in the NSW coastal areas are the most vulnerable because that’s where the human population is increasing,” he said. “As the human population increases on the North Coast, the cost is coming out in the survival of koalas. Road kill — it’s a common way to see wildlife.”
Drought, fire and flood have always been part of the Australian environment, “but when your habitat is fragmented, all these things are exacerbated”, said Erna Walraven, senior curator at Sydney’s Taronga Zoo.
Walraven sees the koala as a flagship species, with the health of their populations serving as an indicator of the wider health of the wildlife of the bush, including bandicoots and wallabies.
“My view is that there are a range of animals under that five-, six-, seven-kilogram range that really [are] quite vulnerable to increased development and land clearing on the coast,” she said. “I think that the koala is in there with a big suite of other species, native Australian icons, that are under threat.” — AFP