Australia facing threat of wildlife catastrophe

Kathy Marks, The Independent 25 Mar 08;

From the tiny tree kangaroo via the greater bilby to the quoll, some of Australia's unique and rare wildlife could disappear in the coming decades as a result of climate change, according to a report by the WWF published today.

The species, already under threat because of wide-scale land clearance and the introduction of exotic predators, could be pushed into extinction by rising temperatures and the knock-on effects, including drought and more frequent and devastating bushfires.

Australia already has the worst record in the world for conserving its beautiful and unusual wildlife. Of all the mammal species that have become extinct in the past 200 years, nearly 40 per cent are Australian. Many surviving creatures are in a precarious state.

Tammie Matson, head of the species programme at WWF Australia, said yesterday: "Australian animals are under so much pressure already that they're not going to be able to adapt to climate change fast enough.

"This is potentially catastrophic. With species like rat kangaroos, hare wallabies and frogs, it could be enough to tip them over the edge."

Rising temperatures are expected to reduce already meagre and fragmented habitats still further. Prolonged droughts could prompt agricultural expansion into wetter areas of northern Australia, which currently provide relatively intact ecosystems.

Conservationists also fear that warmer conditions could favour predators such as cane toads. And marine turtles could find themselves in populations with few or no males, since the sex of hatchlings is determined by the temperature at nesting beaches – the warmer the conditions, the more females are produced.

The report calls for larger areas of the country to be protected as national parks or nature reserves. Otherwise, it says, there will be nowhere for wildlife to move when their environment becomes uninhabitable – which could occur with a temperature rise of just 0.5C.

Burrow-dwelling bilbies (nocturnal marsupials), which are already under threat from foxes, rabbits and feral cats, are likely to find the seeds and fruit on which they feed in short supply, as a result of more frequent and intense bushfires. The loss of vegetation in which to take cover will also make them more vulnerable to attack.

Frogs are particularly sensitive to temperature change, and seven species that dwell in the Australian rainforest could lose more than half of their living space if the temperature increases by one degree.

Birds, too, are expected to suffer from reduced food sources and habitat, with the brilliantly hued Gouldian finch and several species of black cockatoo regarded as vulnerable. As well as predators, weeds are predicted to thrive in warmer conditions, wiping out native plants that provide food for wildlife.

The report points out that if greenhouse gas emissions were reduced to zero overnight, temperatures would still rise by 0.4C by 2050, according to current forecasts. That would be devastating for many Australian species, according to Dr Matson.

"If we were protecting more habitat for these species, there would be a place for them to go," she said. "But we're only protecting 11 per cent of the country. With species like wallabies, frogs and kangaroos, their core climatic habitat will become unsuitable with an increase of just 0.5 degrees in temperature.

"Where a species is already dropping off, climate change is that extra element," she said. "It's a disaster waiting to happen, and it will happen unless we act now to cut emissions."