Environmental groups have accused the Victorian government of failing to perform due diligence before approving planned burns in a forest, home to a nationally endangered species.
The Strathbogie Ranges in northern Victoria was estimated to have a 25,000-strong population of southern greater gliders.
Two local conservation groups, Save Our Strathbogie Forest and Euroa Environment Group, said planned bushfire mitigation burns in the forest this autumn would destroy critical habitat and see hundreds of gliders perish.
Save Our Strathbogie Forest chair Bertram Lobert, an ecologist, said the groups were not opposed to bushfire mitigation.
But he said the use of planned burns must be evidence-based.
"You can't just burn the forest for fuel reduction without consideration of other values," Mr Lobert said.
"The calculation of risk is a complex one, but we're arguing the government hasn't done its groundwork to argue forcefully enough that these areas need to be burned."
The Strathbogie State Forest was declared an Immediate Protection Area by the Victorian Government in November 2019, due to its importance as habitat for the southern greater glider.
The species was promised "enhanced protection from the impacts of bushfires and planned burning" in the Victorian Government's 2019 Greater Glider Action Statement.
'Cryptic' species hard to count
Australian National University research fellow Dr Kara Youngentob has studied southern greater gliders and their habitat for more than 15 years.
She said it was "really hard" to determine the size of southern greater glider populations in all their known habitats.
"They're a very cryptic species which makes them quite challenging to observe," Dr Youngentob said.
"They're also nocturnal and they live in very isolated areas of native forest — all of that makes it very complicated to count them."
The Victorian Government's Arthur Rylah Institute has developed a habitat distribution model for the Greater Glider, and in 2017 performed a targeted population survey in the Strathbogie Ranges.
In February 2023, Save Our Strathbogie Forest group conducted a fresh nocturnal population survey in planned burn sites.
The results indicated glider numbers were "far in excess of most other forest areas in Victoria".
Volunteers counted 48 greater gliders in one of the planned burned sites, a 585 per cent increase on the seven gliders recorded in the same approximate area in the 2017 government-funded survey.
Mr Lobert said his calculations indicated at least 400 gliders would perish if the burns were to go ahead.
Bushfire prevention the intention
Deputy Chief Fire Officer for the Hume region, Jarrod Hayse, said the planned burns were undertaken to reduce the size, intensity and impact of future bushfires.
"Uncontrolled bushfires will have a significantly greater impact on the environment and native species," he said.
A "rigorous planning process" was used to determine the locations for planned burns, Mr Hayse said, with consideration given to environmental values to "mitigate impacts" on native flora and fauna.
"Mitigation measures help protect the environment including the protection of habitat trees, restricted use of machinery, and timing to achieve a low burn intensity."
Dr Youngentob said a planned burn that stayed "low and cool" without scorching the canopy would have less impact on greater gliders, which live in tree hollows.
She said there was a lot of uncertainty about the effectiveness of planned burns, and fire authorities should continue to learn from Traditional Owners.
"Even the best intention and the right kind of burn can sometimes get out of control, and in those situations it can obviously be catastrophic."
