Koalas and other marsupials struggle to recover from Australia’s bushfires

17 July 2020

Published by https://www.nationalgeographic.com

AUSTRALIA – More than six months after cataclysmic bushfires incinerated an Iowa-size swath of Australia, estimates of the staggering number of native animals killed continue to grow even as the fate of surviving wildlife remains largely unknown.

“The data is still coming in, but if anything, the estimate that a billion animals died was more conservative than I realized,” says Chris Dickman, a University of Sydney ecologist who calculated the preliminary death toll. “I think there’s no doubt that some species will go extinct.”

The COVID-19 pandemic abruptly halted most recovery efforts in March. Travel restrictions and social distancing mandates left many scientists homebound and scores of species struggling to survive in apocalyptic landscapes. The lockdown came as the Australian government identified 119 priority animal species “requiring urgent management intervention.”

Australia has the world’s highest rate of mammal extinction, and most of the animals that have disappeared since colonization have been marsupials, or animals whose young develop in their mothers’ pouches. Of the mammal species on the government’s post-fire priority list, the majority are marsupials with declining populations and whose habitat overlaps the range of the bushfires.

Some scientists and volunteers have been able to venture into burn zones to aid koalas, wombats, and other wildlife. What they’re finding indicates the extent of the devastation and the challenges native animals face in bouncing back from fires so intense they obliterated all life in the most ravaged areas.

The fires, according to a new government report, have also laid bare just how little is known about populations of even iconic species like the koala, as well as how little protection conservation laws have provided vulnerable wildlife amid rampant deforestation, development, and climate change.

“Just doing those initial assessments and trying to figure out where we need to focus first has been hampered by this lack of fundamental data,” says Sarah Legge, a wildlife ecologist at Australian National University who helped draft a recovery strategy for the government.

Danger in the trees

Scientists, for instance, long thought few koalas lived in the Blue Mountains, a 2.5 million-acre World Heritage Area of soaring escarpments, deep gorges, and eucalyptus forests 80 miles west of Sydney in the state of New South Wales.

Then in 2013 researchers from a nonprofit conservation organization, Science for Wildlife, began conducting surveys and found large numbers of koalas in the region. That was good news for a threatened species that has long been in decline because of drought, deforestation, and disease. Even better, the scientists discovered that the Blue Mountains population was not only growing, but it was among the most genetically diverse in Australia. It was also largely free of chlamydia, a deadly disease that causes infertility and that afflicts koalas nationwide.

When bushfires began to engulf the Blue Mountains last December, Science for Wildlife’s executive director, Kellie Leigh, scrambled to organize a rescue operation of koalas that had been previously outfitted with radio collars. Authorities gave her team just two days to evacuate them.

“We thought if it all burns, at least we would have got some good genes out,” says Leigh.

Radio trackers fanned out through the scorching and smoky wilderness, and koala catchers scaled 130-foot-tall eucalyptus trees to retrieve the animals. They saved 10 adults and two juveniles. A koala named Houdini had to be left behind as there was no time to extract him from a deep ravine.

The fires burned 80 percent of the Blue Mountains World Heritage Area. Based on her past surveys, Leigh thinks that a thousand koalas died in the conflagrations. A report released June 30 by the New South Wales parliament estimates that the bushfires killed at least 5,000 koalas—as much as a third of the state population—and that the fires destroyed 24 percent of koala habitat on public lands. It concluded that koalas in the state face extinction by 2050. New South Wales has roughly 10 percent of Australia’s total koala population, though estimates of state and national numbers vary because of a lack of surveys. A 2016 study pegged the number at 329,000 koalas nationwide. (Read more: Koalas are not ‘functionally extinct’—yet.)

Across Australia, at least 30,000 koalas died in the fires, according to experts.

“It was pretty depressing and still is,” Leigh says. “You go out to the badly burned areas and there’s nothing living.”

After the fires, her team studied satellite images to identify woodlands with sufficient remaining tree cover. Then they unleashed a koala-detecting dog named Smudge to search for signs of survivors in prospective resettlement habitat.

“He found a lot of burned scat but also some fresh stuff, so we got an idea of where and when koalas were moving through the area,” says Leigh.

Her staff and more than 140 volunteers spent two months building and deploying food and drinking stations for surviving koalas before the lockdown. In March, they returned the rescued koalas to the Blue Mountains.

Leigh has continued to radio track and observe the koalas throughout the pandemic. “They’re not in top-notch body condition, but they’re doing OK,” she says. But “if most of their home ranges burned, they’re not going to have enough resources to survive longer term.”

Safety in burrows

In contrast to the global media attention focused on the koala’s plight, the fate of the marsupial’s closest cousin, the bare-nosed wombat, has been largely overlooked.

Fires tore through the Southern Highlands south of Sydney after midnight on January 5. “When then sun came up, there was nothing, and I mean nothing there but absolute blackness for as far as the eye could see,” says John Creighton, a wombat carer in the town of Bundanoon who had expected to find hundreds of injured animals in the morning. “It was otherworldly silent. There were no birds, no wallabies, no kangaroos.”

There were wombats, though.

“They were the only animal to make it through the fires,” Creighton says of the stocky, bear-like marsupials that spend most of their time in deep burrows. “The wombats were just sitting in the entrance to their burrows, disoriented and in shock as everything they knew had been erased.”

He had already been providing supplemental water and food to the wombats because a years-long drought had left them with little to eat or drink. In the wake of the fires, he stepped up efforts as the animals faced starvation in an obliterated landscape.

Creighton and volunteers set up feeding stations on the grounds of a Buddhist monastery that borders a burned national park. Wombats have a keen sense of smell, and they soon made their way to the food and water. Solitary creatures whose cuddly appearance belies their fierceness, the wombats gathered in uncharacteristically large groups.

“There would be eight wombats around a feeding station,” Creighton says. “They were virtually waiting in line to eat.”

Weeks after the fires, he found a wombat near death. “She was just skin and bones but had the biggest head I’ve ever seen and would have been queen of that forest,” says Creighton. “Wombats like that survived the fires only to die of starvation and thirst.” While there are no scientific estimates of wombat deaths during and after the fires, he says it’s likely that “thousands and thousands of wombats” perished.

Then came torrential rains that finally snuffed out the fires but flooded wombat burrows, killing scores of animals.

Today, community volunteers are still feeding about a hundred wombats at the monastery. “As areas are greening up, animals are moving back,” Creighton says. “But the burned areas are still desolate, and it’s shocking how little feed is growing.”

Back in the field

Evan Quartermain, head of programs for Humane Society International Australia, was on Kangaroo Island in South Australia after firestorms killed half of the isle’s 50,000 koalas. It’s uncertain, he says, if the insects, fungi, seeds, and microbes needed to recover the ecosystem survived temperatures that reached nearly 1,500 degrees Fahrenheit in some places. “It may be that some building blocks of the ecosystem will not come back,” he says. (Read more: Some of Australia’s forests may not recover.)

Many crucial wildlands had been destroyed by development before the fires. The New South Wales parliamentary koala inquiry found that even after laws were implemented to protect koala habitat, deforestation increased because of lax enforcement of environmental regulations. The state government, for example, has approved the construction a coal mine in prime koala habitat in New South Wales. Accelerating climate change and severe drought have put further pressure on habitats.

A wildlife study commissioned by WWF Australia found a 90 percent reduction in ground-dwelling animals in parts of New South Wales surveyed in early March. Elsewhere, scientists are most concerned about the survival of already endangered species such as the Kangaroo Island glossy black cockatoo and Kangaroo Island dunnart, a rat-size marsupial, whose limited habitat burned in the fires. But even less vulnerable animals, like the platypus and a small eucalypt-dwelling marsupial called the greater glider, are now in peril due to the sheer amount of land lost. In the state of Western Australia, fires burned the habitat of one of the last mainland populations of quokkas, the smiley-faced marsupial that has starred in thousands of selfies. As for the iconic kangaroos, thousands likely died, but with a population estimated at 50 million, scientists aren’t concerned about the species’ survival.

As pandemic restrictions ease, scientists are planning their return to field and volunteers are putting the tens of millions of dollars in international donations to work to help wildlife. The federal government has allocated $200 million Australian dollars toward wildlife recovery. (Learn more about how you can help Australia recover.)

University of Sydney biologist Valentina Mella’s research established that koalas will use drinking stations during drought and heatwaves. She is now working with wildlife rescue group WIRES to distribute 800 drinking stations around Australia. WIRES is also issuing grants to communities for habitat restoration while Humane Society International is providing financial support to wildlife carers and helping them prepare for the fires to come. Quartermain says koalas rescued and later released on Kangaroo Island were implanted with microchips and will be tracked to keep tabs on their condition.

Science for Wildlife, meanwhile, is launching a six-month survey of koala habitat in the Blue Mountains. But Leigh is relieved to already have found one particular koala: Houdini, the radio-collared marsupial she could not rescue during the fires.

Houdini earned his name for his skill at escaping capture, and he proved adept at eluding the bushfires. “He was in a steep gully with huge trees, which don’t burn easily,” Leigh says. “He has given us some hope that in other steep gullies that suffered a similar low-intensity burn, we might find more surviving koalas.”

Print Friendly, PDF & Email
WP-Backgrounds Lite by InoPlugs Web Design and Juwelier Schönmann 1010 Wien