Drone Buzz Over Australian State Forests, No Worries for Gliders

A rehabilitated greater glider possum is seen in the Higher Ground Raptor Centre in Bomaderry, Australia, on Jan. 28, 2020. (John Moore/Getty Images)

Concerns over drones monitoring native endangered species of Australian gliders in Victoria appear to have been overblown after researchers found creatures could care less about the night-flying robotic invaders.

Gliders, also known as flying possums, are marsupial mammals of Australasia that volplane between trees, much like flying squirrels in the northern hemisphere.

The drones were brought in to resurvey and monitor the glider populations last year under a court order by Victoria’s supreme court after concerns were raised about VicForests decision to fell trees in areas also populated by endangered glider species—the yellow-bellied glider and the greater glider.

Since then, VicForest has been trialling drones to monitor state forests in East Gippsland and the Central Highlands in Victoria for fauna.

The night-flying drones used by VicForests can spot greater gliders, owls, possums and other species through thermal imaging cameras.

Once a heat spot is detected through the thermal imaging camera, the drone switches to a regular video camera and the floodlight to illuminate the canopy and identify the animal.

Drones Helping Survey Impenetrable Forest

The use of drones has been encouraging and has provided great insight and data while removing the danger of physically surveying the dense native bushland, said VicForests environmental performance director Bill Paul.

“Some of our forest is impenetrable, and some of it is very difficult to walk through,” Paul told AAP. “We seem to be coming up with a reasonable process to make that work to find the gliders ... as the court requires.”

Melbourne University research fellow for Forest Resilience and Adaptation Benjamin Wagner, also a consultant on this trial, said he was surprised by how the animals didn’t show interest in the drones when there were concerns about the drones disrupting the animals.

“The video footage is quite interesting because you see greater gliders foraging on leaves or making their way up into the canopy, maybe getting ready for a glide,” he said, reported AAP.

“Which is really encouraging as well because it also means that you can observe these animals in their natural habitat ... and you don’t influence your observations by (appearing) a potential threat to them.”

Wagner is an expert in the greater gliders with a PhD on the greater glider’s habitat, using remote sensing and a plotted network in East Gippsland, Victoria, to study the structure and nutritional value of mixed-species forests in relation to the occurrence of the greater gliders.

Wagner said the data from the drones showed the gliders tend to move around their home range freely even with the drones around, and surveys that did not locate any gliders in that area would be repeated three times to confirm the area was free of gliders or animals and was safe to harvest.

“In the next week or two, we might be close to getting the final advice from our expert ... and from there, we need to sign up drone companies and develop contracts with them,” Wagner said.

“Then we’ve got to do the surveys, so harvesting is still a little way off.”

Endangered Greater Gliders

The greater gliders are Australia’s largest nocturnal gliding marsupial that can glide for up to 100 meters; they are more related to the lemur-like ringtail possum than arboreal possums such as the sugar glider.

The greater gliders were previously considered one species until 2020, when genetic differences showed there are three different species; the northern, central and southern.

Great Gliders are characterised by the thick, dark grey-brown fur on their back, creamy white fur on their underside, a long furry tail and large furry ears; they can be found in different dark and light-coloured shades variations.

Great Gliders are found along the east coast of Australia, from central Queensland to central Victoria. They are forest-dependent animals that prefer old hollow-bearing trees in moist forest types.

These hollow-bearing trees provide shelter and nesting for each family group that uses multiple den trees within its home range and feeds off young eucalyptus leaves and buds, with a preference for certain types.

Due to their high dependence on forests, their habitat loss has been increased through tree clearing, forest destruction and bushfire, which pose a great threat to the Great Gliders. Some Greater Glider populations have also been found to have an increased threat from powerful owls.

According to the Australian Conservation Foundation (ACF), the greater glider population has declined by 80 percent in just 20 years and was added to the list of endangered wildlife in July 2022, having previously been listed as vulnerable.

Without the old fully, grown forests and hollow-bearing trees, these greater gliders cannot survive. So pre-harvest surveys of proposed timber coupes have been introduced as part of the Forest Protection Survey Program.

The Australian National University and the University of Melbourne have both been monitoring and identifying the species and forests for long-term protection.

Impact of Timber Harvesting

Due to the decrease in native timber resources because of bushfires, animal habitat protection and consumer preferences, the Victorian Government introduced the Victorians Forestry Plan (pdf) to provide more than $200 million (US$134 million) support to help workers and business transition ahead of the commercial native timber harvesting ending in 2030.

Victorian Greens introduced a bill to Parliament on Feb. 21 that would legislate an end to native forest logging in Victoria from June 2023 and protect the habitats of endangered species.

The Greens alleged that VicForests had been illegally logging forest areas across the state by “salvage logging” in highly sensitive areas, including national parks such as the Wombat State Forest and the Dandenong Ranges National Park.

They also said the harvested wood and pulp from highly sensitive areas were being used for commercial purposes, according to a media release.

“The state’s last paper mill is about to close permanently, which means the Andrews Labor Government has no more excuses for allowing logging to destroy our native forests,” said Victorian Greens deputy leader Ellen Sandell.

“The government has been propping up the logging industry with millions in taxpayer dollars, even when VicForests has been found to be illegally logging in areas right across Victoria. Logging in native forests needs to end now—not in seven years when we have no forests left.

“If the Government cared about threatened species habitat, they would bring forward the transition package for workers, move to getting our wood from plantations, and support the Greens’ bill to stop native forest logging now.”