Up to 30 per cent of koalas on the NSW mid-north coast region could have been killed in the recent bushfires, according to Federal Environment Minister Sussan Ley.
The majority of the state's koalas, which are numbered at 15,000 to 28,000, live in the region, meaning that more than 8,000 koalas may have perished.
"It may well be up to 30 per cent of the population in that region [was killed], because up to 30 per cent of their habitat has been destroyed," Ms Ley told ABC Radio's AM on Friday.

An injured koala receives treatment after its rescue from a bushfire at the Port Macquarie Koala Hospital. Source: Getty
"We'll know more when the fires have calmed down and a proper assessment can be made."
Ms Ley said the government had allocated a $6 million budget which will build koala corridors and reintroduce hospitalised koalas to their habitat.
"The koala is one of our most iconic species," she said.
It came as environmental organisation Aussie Ark said NSW was in a "wildlife state of emergency."

A sign, indicating koalas live in the area, stands in a burnt out forest near the town of Taree. Source: Getty
"Substantial investments have been seen by governments in firefighting, national parks and the protection of private properties and infrastructure. This is where the focus has been," Aussie Ark president Tim Faulkner said on Friday.
"Nobody has declared a native wildlife crisis, yet that is exactly what it is – a native wildlife state of emergency. So much has been lost already and it won't come back without help," he said.
"What is needed is a mass upscaling of initiatives and projects that directly impact wild native wildlife."
The nation's horror bushfire season has so far burnt more than five million hectares and killed nine people.
Fires continue to burn around NSW, with almost 1,300 firefighters in the field on Friday.
The Bureau of Meteorology expects the fire danger to worsen into the new year with increasing heat and winds.
Additional reporting: AAP