Contrasting responses to the 2019–2020 wildfires by the greater glider and yellow-bellied glider in north-eastern and south-eastern New South Wales

The 2019–2020 wildfires in south-eastern Australia were the most extensive and severe of any recorded since European settlement, and the impacts of these fires on biodiversity are expected to be devastating. By using walked spotlighting transects, we investigated the impact of these fires on two forest-dependent species, the greater glider and yellow-bellied glider, across a range of sites in both north-eastern and south-eastern New South Wales (NSW), where one or both species were known to be present before the fires. In 2020–2021, in north-eastern NSW, greater gliders were observed at 57 (76%) of the 75 sites where they had been recorded previously, and at an additional three sites where they had not been recorded. Yellow-bellied gliders were observed at 11 (23%) of the 48 sites where they had been recorded previously. In 2021, in south-eastern NSW, greater gliders were still present at all nine long-term sites, but in greatly reduced numbers on the burnt sites. The yellow-bellied glider was also reduced in abundance on the burnt sites. We found no significant relationship between glider presence for both species and fire severity in the local landscape in both regions; however, greater glider counts were reduced on most severely burnt sites. Other factors, including elevation and logging history (indicators of habitat quality), appeared to condition fire effects. The decline in populations of both species at low–moderate elevations, regardless of fire severity, is of concern and requires further investigation. Climate change and the associated impacts of prolonged droughts, extended heatwaves, and more frequent wildfires could largely be responsible for some of these changes in glider occupancy.