“EXTRAORDINARY” … SEARCH FINDS 59 GREATER GLIDERS IN ONE NIGHT

But they’re still missing from forests severely burnt 5 years ago

Ecologists have counted up to 59 endangered greater gliders per night during spotlight searches of healthy forest on the New South Wales Southern Tablelands.

Those numbers infer a greater glider density of up to 140 gliders per 50 hectares.

It’s an incredible bounce back. Populations crashed by as much as 80% in the last 20 years because of land-clearing and logging, and the 2017-2019 drought, 2019 heatwaves, and the mega fires of 2019-20 – extreme events made worse by climate change.

Just published research reveals greater glider numbers in the best habitat were 45% higher than pre-2019 counts (before the drought and fires).

The surveys were organised by the community conservation group K2W Link. It’s part of Cores, Corridors, and Koalas - a partnership between the Great Eastern Ranges (GER) and WWF-Australia to restore and connect critical habitat for forest-dependent native animals.

Experienced ecologists Peter and Judy Smith conducted the spotlight searches.

“It’s been fantastic to see greater gliders bounce back to well above pre-fire, pre-drought levels in the best and most lightly burnt habitat,” Dr Peter Smith said.

“Because of their low reproductive rate, we didn’t think that they’d be capable of making such a strong recovery. The rapid increase in numbers is extraordinary,” he said.

“To find that many is exciting, it’s amazing. It shows that greater gliders can thrive when they have undisturbed habitat. So often their forest homes have been destroyed or degraded,” said Dr Kita Ashman, a conservation scientist with the World Wide Fund for Nature-Australia.

Since 2015, the Smiths have been spotlighting along the same transects (straight lines through a forest) to study tree-dwelling mammals in the south west corner of Blue Mountains National Park and the adjoining Mares Forest National Park and Wombeyan Karst Conservation Reserve.

“The massive increase in glider numbers in suitable habitat has been aided by high rainfall and good eucalypt growth since the fires,” Dr Smith said.

“It shows the importance of the best glider habitats. They support high numbers of gliders and, if conditions are right, a big post-fire population boom that provides a source of animals to aid in recovery more widely,” he said.

But the revival is uneven. In severely burnt forest in Jenolan Karst Conservation Reserve, the impact of the 2019-20 fires is still evident. Trees that survived have no canopy leaves. Surveys by the Smiths have found no trace of greater gliders.

“We were very disheartened to see the gliders wiped out in the most severely burnt sites, with no sign of any recovery five years later,” Dr Smith said.

“In the immediate aftermath of the fires, there was no live eucalypt foliage for the gliders to feed on and they disappeared from these areas. When greater gliders are eliminated in an area it takes a long time for them to recolonise,” he said.

When a wildfire in 1994 burned 90% of Royal National Park, south of Sydney, greater gliders disappeared from the reserve and were not recorded again until 18 years later.

“That’s why the remaining greater glider strongholds are so important,” Dr Smith said.

“The forests in Mares Forest National Park and the southern end of Blue Mountains National Park now support exceptional numbers of greater gliders and are vital for the species' recovery in this region,” he said.

Dr Smith emphasised the critical need to reduce the incidence and extent of high to extreme-severity fires.