Koala populations in NSW are heading towards extinction with drought, bushfires and logging resulting in "death by a thousand cuts".
Conservationists on Tuesday told a NSW parliamentary inquiry that drastic changes are needed to save dwindling koala populations.
World Wildlife Fund policy manager Dr Stuart Blanch says the summer bushfire crisis had an enormous impact on koala habitats.
Preliminary surveys in the state's north indicated some populations had shrunk by 80 to 85 per cent following the fires, Dr Blanch said.
Some NSW koala populations could be extinct by 2050, or sooner, he added.
"They are heading towards extinction increasingly. I wouldn't be surprised, based on what we're hearing, if we lost 10,000 koalas from the fire and the drought."
Previous estimates based on habitat loss have suggested as many as 8000 koalas may have died in NSW during this bushfire season.
Academics have suggested more than 800 million animals were killed in the unprecedented blazes across the state.
Dr Blanch says new incentives are needed to motivate landowners to preserve land.
"Farmers are the primary conservationists in some habitats - we need incentives for them to protect land," he said.
Australian National University biologist Dr Kara Youngentob says koalas in eastern NSW are facing rapid habitat loss.
"It's death by a thousand cuts for the koala," she told Tuesday's inquiry.
"There are big gaps in our understanding of how koala populations respond to fire. Basic knowledge about when they can safely be released is lacking."
NSW Environmental Defenders Office lawyer Cerin Loane says the bushfires have made a bad situation worse.
"Back in August last year, we highlighted the fact that laws in NSW didn't protect koalas.
"The events of the last summer have changed the situation quite drastically."
WWF and the environmental defenders argue koalas should be listed as an endangered species and land management policies should be overhauled to protect their habitat.
"People are telling us they want a moratorium on logging and land clearing," Ms Loane said.
"If we've really lost so much habitat what we've got left needs to be protected."
Australian Associated Press