Koalas could be wiped out

IT’S GOING TO BE SOME TIME BEFORE WE GET IN TO ASSESS WHETHER PARTICULAR SPECIES ARE STILL THERE OR NOT, BUT ANYWHERE FROM 20 TO 100 PLANTS AND ANIMAL SPECIES THAT WERE ALREADY THREATENED WERE IN THE PATH OF THE FIRES AND WOULD BE AT REAL RISK. CHRIS DICKMAN, PROFESSOR IN TERRESTRIAL ECOLOGY FROM SYDNEY UNIVERSITY’S SCHOOL OF LIFE AND ENVIRONMENTAL SCIENCES

KOALAS could become extinct in eastern Australia within a generation and as many as 100 species of plants and animals completely wiped out across the country as a result of the horror bushfire season, experts believe.

The number of animals killed is almost impossible to quantify, but estimates based on existing wildlife density patterns suggest a tally in excess of one billion.

Part of the reason why we have such a poor grasp of the bushfires’ impact on native animals is that “monitoring in Australia has been really quite poor” over the past 20 years, said Chris Dickman, professor in terrestrial ecology from Sydney University’s School of Life and Environmental Sciences.

“As a nation we’ve been sleepwalking to this catastrophe,” he said.

“It’s going to be some time before we get in to assess whether particular species are still there or not, but anywhere from 20 to 100 plants and animal species that were already threatened were in the path of the fires and would be at real risk.”

Among the anticipated losses is the long-footed potoroo, a member of the rat kangaroo family, which had a small range in Victoria’s Gippsland region and southern NSW.

“As far as we can tell, almost all of its habitat has been burnt,” Prof Dickman said.

The bushfire catastrophe would also likely claim some species that had only been identified in the past five years, including two insectivorous marsupials native to southeast Queensland’s Scenic Rim region: the silverheaded antechinus and the black-tailed dusky antechinus.

Koala populations have been severely impacted by the blazes, with estimates that 8000 have been killed in bushfires in northern NSW and as many as 30,000 on Kangaroo Island.

Dr Stuart Blanch from WWF Australia said koalas in eastern Australia were on track for extinction by the year 2050, but the 2019-20 bushfires “have brought that extinction timeline forward”.

Koala numbers in northern NSW and Queensland declined by 42 per cent between 1990 and 2016, mainly because of habitat loss brought on by land clearing, deforestation and climate change, Dr Blanch said.

The Queensland government provided similarly grim statistics when it launched a koala conservation draft strategy in December, with the state environment minister Leeanne Enoch claiming that “koala populations have decreased by 50-80 per cent in southeast Queensland habitat areas over about 20 years”.

WWF’s warning about koalas being wiped out in eastern Australia had been calculated on the population declining at a steady rate, Dr Blanch said, “but climate impacts including drought and bushfires are happening a lot quicker than expected so it’s reasonable to conclude the extinction risk will come well before 2050”.

Between one quarter and one half of Australia’s koala population could have perished in the current bushfire season, he said.

Prof Dickman said at least half the animals’ habitat on Kangaroo Island and one quarter of its range in northern NSW had been destroyed this bushfire season – “that’s a big hit” – but he stressed that there were still areas for the animals that had not been destroyed.

“Koalas do have a big range, and even though the fires have covered over 10 million hectares there’s still a very large area of koala habitat that remains unburnt,” he said.

The plight of the eucalyptus-munching marsupial in the bushfires has dominated coverage of the crisis, but koala conservation efforts would flow on to other native animals, he added.

The Queensland state government’s proposed plan to protect more than 570,000 hectares of land for koalas would also offer protection to “other beautiful charismatic marsupials, forest birds, reptiles and all the invertebrates associated with the forest”, Prof Dickman said.

“So, if you like, the koala is a fantastic umbrella species,” he said.

Some 34 native mammal species had become extinct since white settlement in Australia, and there were real fears that the current bushfires would push more species and populations to the wall, Prof Dickman said.

“There was a pretty decent glider population in [Sydney’s] Royal National Park, but a fire there in 1994 wiped them out,” he said. “There was one possible sighting over the past five years, but effectively, they’re gone.”