The federal government has committed $50 million to a wildlife recovery fund as the damage toll on the nation's flora and fauna from the recent bushfire crisis has started to be realised.

Images of burnt koalas in bandages have become the face of the bushfire crisis with images strewn across the world and on Monday the government indicated how significant the impact of the fires has been on koala populations.

Federal Environment Minister Sussan Ley said the recent bushfire crisis may result in the koala classified as "endangered".

"We have got a threatened species scientific committee that manages the listing of all endangered species," she said.

"I have spoke with the chair of the committee, Helene Marsh, and I have said given the extraordinary hit ... it may be necessary to bring forward the assessment that they would be doing in any case, to see whether in certain parts of the country, koalas move from where they are, which is often vulnerable, up to endangered."

It comes as the federal government announced on Monday it would give $50 million towards devastated wildlife.

The money will be split in half, with $25 million to go towards wildlife carers, hospitals and schools and the other $25 million will be managed by the threatened species commissioner Dr Sally Box.

Ms Ley made the announcement in Port Macquarie Koala Hospital on Monday morning along with Treasurer Josh Frydenberg and Dr Box.

Mr Frydenberg said the $50 million was an "initial contribution" to protecting wildlife and the money would go towards restoring habitat.

"Some eight million hectares have been burnt and we know that our native flora and fauna have been very badly damaged," he said.

The other $25 million will be managed by Dr Box to convene an expert panel to provide advice.

"This expert panel will have a few roles. We will look at trying to assess the impacts of fires on our threatened species, our wildlife and plants and animals," Dr Box said.

"Mapping to try and understand where the fires have been and which species may have been in their path has already begun. We will look at the maps to further assess the impacts. We will prioritise the species, the places that we most need to focus our efforts and look at the type of actions that might need to be done."

Dr Box said scientists had estimated about 30 per cent of koala habitat had been lost in northern NSW.

Last week, Australian mammal expert Professor Chris Dickman estimated more than a billion animals had been killed.

"One billion sounds like a very big number but it's almost certainly an underestimate because of the groups I don't include," the University of Sydney academic told AAP on Thursday.

Bats, frogs and invertebrates haven't been included in the estimate.

The worst-affected animals would be the "large and slow-moving ones" such as koalas but species with small populations are at risk of imminent extinction, he added.

"We're clearly at risk of losing a significant proportion of biodiversity and because much of Australian biodiversity occurs only here, it's a global loss," he said.

Dr Christine Hosking from the University of Queensland's Global Change Institute said one billion dead animals is a "very reasonable" estimate.

While many animals would have perished in the blazes, many more will die because of a lack of food and the charred, barren landscapes which leave small mammals vulnerable to predators, she said.

"The whole food chain is affected," Dr Hosking told AAP on Thursday.

"These forests will remain empty for quite a long time."

The koala expert believes it could take up to 100 or even 200 years for some forests to completely recover and the ecology will not only be degraded, but changed completely.

"We've got threatened species that may go extinct after this as well," she said.