Australia listed koalas along much of its east coast as "endangered" on Friday, following a dramatic decline in numbers as the native marsupial's habitats were hit by prolonged drought, bushfires and developers cutting down trees.

Scientists and academics have been warning that the iconic Australian mammal could become extinct unless the government immediately intervened to protect them and their habitat.

"The new listing highlights the challenges the species is facing," Environment Minister Sussan Ley said in a statement. "Together we can ensure a healthy future for the koala and this decision ... will play a key role in that process."

Ley said koalas in the states of New South Wales, Queensland and the Australian Capital Territory will be listed as endangered versus their previous designation of vulnerable.

"We are taking unprecedented action to protect the koala," the minister said, highlighting a recent government promise of $36 million to protect and recover koala habitats.

Australia has lost about 30% of its koalas over the past three years, the Australian Koala Foundation said last year, with numbers estimated to have dropped to less than 58,000 from more than 80,000 in 2018 with the worst decline in New South Wales, where the numbers have dropped by 41%.

A World Wide Fund for Nature study estimated bushfires in late 2019 and early 2020 had killed or injured more than 60,000 koalas when flames burned more than 17 million hectares (65,630 square miles), an area nearly half the size of Germany.

But even before the fires, koala habitats had been in rapid decline due to land clearing for agriculture, urban development, mining and forestry. Koalas dwell mostly in eucalyptus forests in eastern states and on the coastal fringes.

Environment groups welcomed the decision although they said it should have happened much earlier.

"We should never have allowed things to get to the point where we are at risk of losing a national icon," International Fund for Animal Welfare Manager Josey Sharrad said.

"If we can't protect an iconic species endemic to Australia, what chance do lesser known but no less important species have?"

The koala, a globally recognized symbol of Australia's unique wildlife, had been listed as "vulnerable" on the eastern coast just a decade earlier.

Environmentalists welcomed the koalas' new status but condemned Australia's failure to protect the species so far.

"Koalas have gone from no-listing to vulnerable to endangered within a decade. That is a shockingly fast decline," said WWF-Australia conservation scientist Stuart Blanch.

"Today's decision is welcome but it won't stop koalas from sliding towards extinction unless it's accompanied by stronger laws and landholder incentives to protect their forest homes."

Conservationists said it was hard to give precise figures on koala populations in the affected eastern states.

But estimates by an independent government advisory body – the Threatened Species Scientific Committee – indicated that koala numbers had slumped from 185,000 in 2001 to just 92,000 in 2021.

'Losing a national icon'

Alexia Wellbelove of the Humane Society International said east coast koalas could be extinct by 2050 if no action was taken.

"We can't afford any more clearing," she said.

The Australian Conservation Foundation said its own research showed that the federal government had approved the clearing of more than 25,000 hectares (62,000 acres) of koala habitat since the species was declared vulnerable a decade ago.

"Australia's national environment laws are so ineffective they have done little to stem the ongoing destruction of koala habitat in Queensland and NSW since the species was supposedly protected a decade ago," said the foundation's nature campaign manager, Basha Stasak.

"The extinction of koalas does not have to happen," Stasak added.

"We must stop allowing their homes to be bulldozed for mines, new housing estates, agricultural projects and industrial logging."

Australia's koalas had been living on a "knife-edge" even before the devastating "Black Summer" bushfires of 2019-2020 because of land-clearing, drought, disease, car strikes and dog attacks, said Josey Sharrad, wildlife campaign manager at the International Fund for Animal Welfare.

"We should never have allowed things to get to the point where we are at risk of losing a national icon," Sharrad said.

"The bushfires were the final straw. This must be a wake-up call to Australia and the government to move much faster to protect critical habitat from development and land-clearing and seriously address the impacts of climate change."