New research estimates that the 2019-2020 bushfire crisis, together with prolonged drought and heatwaves, have had a devastating impact on the gliders.

One survey commissioned by the World Wide Fund for Nature-Australia and the Great Eastern Ranges Initiative (GER) looked solely at the bushfire impact.

The project is supporting GER's regional partner networks to restore habitat for forest-dependent native animals post-fire in ten priority locations stretching from Victoria to Queensland.

Local ecologists and glider experts, Dr Peter Smith and Dr Judy Smith, used spotlighting and wildlife cameras to survey six burnt sites at Wombeyan and Jenolan between November and December 2020. Pre-fire surveys of the region's tree dwelling mammals were used for comparison.

"Sadly, we found a significant decline in the population of greater gliders in the research area. From this, we have estimated that the overall reduction in the greater glider population of the Greater Blue Mountains World Heritage Area as a result of the fires alone was around 45 per cent," Dr Peter Smith said.

The pair then did further spotlight surveys in the Blue Mountains, in a separate but related study, which also looked at sites unaffected by fires.

"This revealed that the drought and heatwaves leading up to the fires had a major impact even in unburnt areas," Dr Peter Smith said.

"Factoring in drought and heatwave impacts, we estimate the overall reduction in the Blue Mountains greater glider population to be about 60 per cent. Things are looking even worse for greater gliders."

Great Eastern Ranges Initiative CEO Gary Howling said the research highlighted the importance of the wildlife corridors such as the 320,000 hectare Kanangra-Boyd to Wyangala (K2W) Link.

"The K2W Link provides a refuge for a significant number of glider species and was largely unaffected by the 2019-2020 bushfires," Mr Howling said.

"This corridor will significantly boost the recovery of the Blue Mountains. It forms a natural highway enabling gliders and other wildlife to safely move across the landscape to repopulate the World Heritage Area. Having a network of connected habitat in these areas provides insurance populations of threatened species."

WWF Australia threatened species and climate adaptation ecologist Dr Kita Ashman said the report added to the growing awareness about the impact of fires on greater gliders following years of drought and heatwaves.

"It is alarming that more than half the Blue Mountains greater glider population may have perished. They are one of several species heavily impacted by the bushfires," she said.

"WWF is supporting the Great Eastern Ranges Initiative through our Regenerate Australia plan - the largest wildlife and nature regeneration program in the nation's history.

"By working with a wide range of partners, like GER, to regenerate and restore habitat, WWF will help greater gliders, koalas and other species to recover after last year's fires."

Additional funding is needed to expand on the critical post-fire recovery work that is being carried out through the WWF-GER partnership across eastern Australia.

Contributions to Cores, Corridors and Koalas can be made online at www.ger.org.au/donations.