Australia’s fires have pushed as many as 100 threatened species closer to extinction

“It was just devastating,” said Ballard from the University of New England in Armidale. “You could smell dead animals in the rocks.”

But some wallabies, his team discovered, were still alive. “All you can do is focus on the survivors,” he said.

Australia’s forests and wildlife evolved alongside periodic wildfires. What’s different this year is the vast extent of land burned – an area as big as Kentucky – against a backdrop of drought and searing temperatures attributed to climate change. Last year, among the driest in more than a century, saw temperatures that routinely topped 104 degrees Fahrenheit.

Not all animals will perish in the blazes. Some can shelter in rock crevices or hide deep in underground burrows. Yet when survivors emerge into a fire-scorched wasteland, they will face hunger, thirst and non-native predators, including introduced foxes and feral cats.

Since fires swept through parts of Oxley Wild Rivers National Park nearly two months ago, there’s been little rain and no green shoots.

So Ballard’s team has trekked through the ash-covered forest carrying water and sacks of sweet potatoes, carrots and food pellets.

“There are so few left that, with a species this rare, every individual counts,” he says.

Elsewhere in New South Wales, conservation workers are dropping vegetables from airplanes into scorched forests, hoping that wallabies and other species find a meal.

In the state of Victoria, authorities estimate that brush-tailed rock wallabies lost 40% of their habitat as did another rare marsupial, the long-footed potoroo, according to a preliminary damage assessment.

University of Sydney ecologist Christopher Dickman estimated that more than 1 billion animals have been killed so far. His calculations took previously-published animal density numbers for different vegetation types and multiplied that by acreage burned.

He says that number does not include bats, amphibians, insects or other invertebrates.

The wildlife toll includes tens of millions of possums and small marsupials known as gliders, which live in tree tops and can leap extraordinary distances by using a parachute-like membrane of skin between their ankles and wrists. State officials in Victoria predicted more than a 25% reduction in glider numbers from the fires.

“The implications for some species are pretty grim,” Dickman said. “If we can’t protect them here, they’re gone. No one else has them.”

The Australian government announced Monday that it was spending $50 million on emergency wildlife rescue efforts and habitat recovery.

Fires are still burning in the Blue Mountains, a UNESCO World Heritage site west of Sydney – one of the last strongholds of the regent honeyeater, an elegant black and yellow bird that has already lost 95% of its breeding habitat since European settlers arrived in Australia.

There are only 300 to 400 of the birds left in the wild, says Ross Crates, an ecologist at Australia National University. They are dependent on nectar from certain eucalyptus tree blossoms, but the dry weather has meant that many trees are producing no nectar.