Development in prime koala habitat is exacerbating the effect of drought and bushfires on the iconic marsupial.
Credit: Graham Price
The biggest threat facing koalas is the loss of habitat due to road building and development on Australia's eastern coast - traditional koala country.
The joke, says Deborah Tabart, is that fussy koalas like to make their home in land which is also prime real estate and are often pushed out of their habitat by farming or development.
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 Tabart, who heads up the Australia Koala Foundation in Brisbane, Queensland, believes the animal's plight is as bad as she has seen it in her 20 years as an advocate.
"In southeast Queensland we had them listed as a vulnerable species which could go to extinction within 10 years. That could now be seven years," she says. "The koala's future is obviously bleak."
Southeastern Queensland has the strongest koala populations in the vast country, meaning extinction here spells disaster for koalas across Australia.
Bushfire bonanza
"I've driven pretty much the whole country and I just see environmental vandalism and destruction everywhere I go," she says. "It's a very sorry tale. There are [koala] management problems all over the country."
Massive bushfires - which raged in the country's south for weeks during the Australian summer, burning a million hectares of land - are likely to have also killed thousands of koalas.
Meanwhile they also have to contend with Australia's worst drought in a century, genetic mutations from inbreeding in some populations, and the widespread incidence of chlamydia - a type of venereal disease that affects fertility.
Moreover, pet dogs often fatally attack the animals, says Tabart. "In southeast Queensland the koalas are found in people's backyards and the dogs just munch on them."
Confusing the whole 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 many 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, says biologist Frank Carrick at the University of Queensland in Brisbane.
Panic button
Carrick, who leads a koala study project, estimates the national population of the marsupial at about one million. And while he doesn't personally 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." That's because we keep chopping down trees and their food source, he says. Carrick says it would take 40 to 50 years for the koala to sufficiently recover from the impact of the latest Victorian bushfires, drought and development.
"[But] exactly how small do we want the population to be before we push the panic button?" he says.
Dan Lunney, a senior research scientist with the New South Wales state Department of Environment and Conservation in Sydney, says 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 says. "The issue is not how many there are; but it's whether they are declining or not." Lunney says 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 says. "But they do have a threshold at which they can't continue."
Road kill
Lunney argues that 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 says. "Road kill - it's a common way to see wildlife."
Drought, fire and flood have always been part of Australian life, says Erna Walraven, senior curator at Sydney's Taronga Zoo. "But when your habitat is fragmented, all these things are exacerbated." Walraven sees the koala as a flagship species, with the health of their populations serving as an indicator of the wider health of the bush wildlife, 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 says.
"I think that the koala is in there with a big suite of other species - native Australian icons - that are under threat."
Madeleine Coorey is a writer with AFP in Sydney, Australia
Drought and development driving koala decline
Our human-centric attitude to wildlife, and the destruction of their habitat, is totally shameful and shows a callous disregard for our indigenous creatures. There needs to be reserves within wildlife corridors for the survival of these well-loved icons of Australia. We cannot morally or ethically just destroy the habitat of native animals without making some restitution. Our shameful loss of biodiversity is one of the worst in the world. While our human population is growing and spreading, boosting our economy no doubt, our native animals are suffering decline, drought and deaths. Any native animals that manage to recover from road accidents, loss of habitat and/or bushfires, should be placed in protected areas and not where they are continually threatened.
Vivienne of Heidelberg
Koala culling
On Kangaroo Island off South Australia we have the opposite problem - koalas are an introduced feral species. Like many feral species such as rabbits, they breed too much at consequently eat too much. They are running amok, destroying habitat for other native animals on the island.
The obvious solution is to cull them, like we would any other feral species that is endangering native wildlife – but just because koalas are cute the politicians don’t dare cull them. Instead we have a totally ineffective and extremely expensive sterilisation program.