Sydney: As bushfires continue to rage across Australia, ecologists fear that half a billion animals might have been killed in the crisis.

A study by the University of Sydney said close to half a billion mammals, birds, and reptiles have been wiped out in the bushfires that erupted since September last year.

With the fires still raging in Queensland, Victoria, and New South Wales continues to rise, the death toll of animals is likely to increase.

Slow-moving koalas are one of the hardest-hit species, as the fires have killed nearly 8,000 koalas and 30 per cent of the koala colony in New South Wales has been destroyed. More so, they only eat leaves from the eucalyptus tree, which are filled with oil, making them highly flammable.

Nature Conservation Council ecologist Mark Graham said koalas in particular have been devastated by the fires, because they “really have no capacity to move fast enough to get away.”

He further said, “The fires burned so hot and fast that there has been significant mortality of animals in the trees, a big area that is still on fire and we will probably never find the bodies.”

As per a Reuters report, Australia’s bushland is home to a range of indigenous fauna, including kangaroos, koalas, wallabies, possums, wombats, and echidnas. Officials fear that 30 percent of just one koala colony on the country’s northeast coast, or between 4,500 and 8,400, have been lost in the recent fires.

Meanwhile, the human death toll is at least 20, with many people still missing. With fires still ravaging, authorities have urged tens of thousands of people to evacuate from their homes and move to safer areas.