A new study has revealed that greater gliders, Australia's largest gliding marsupial, do not glide as far as previously believed. Researchers tracked 41 flights in New South Wales forests and found the average glide distance was just 19 metres—far shorter than the 100 metres suggested in an 85-year-old study.
Study Details and Findings
Using infrared binoculars, lasers, and tape measures, scientists recorded data on launch and landing heights, horizontal distance, and glide angle. The findings were published in Australian Mammalogy. Lead author Dr Ana Gracanin, a conservation biologist at the Australian National University, said the results challenge long-held assumptions about the endangered animals' travel capabilities.
“The term ‘greater’ refers to their large body size, not the distance they traverse,” Gracanin explained. The longest flight recorded in the study was just under 50 metres.
Witnessing Greater Gliders in Action
Despite their shorter glides, seeing a greater glider in flight remains breathtaking. On average, they launch from trees at about 22 metres above ground and land on another tree trunk at about 5 metres. Gracanin described the sight: “It goes from being this hunched-over ball of fluff at the top of a tree looking down at you, to suddenly spreading out its limbs and flying over your head like a magical flying carpet, or this weird stingray-UFO thing in the sky.”
To stay aloft, they use a membrane stretching from their elbows to their ankles. “They get to the top of a tree, launch, spread out their elbows, tuck their paws under their chin and soar through the air,” she said.
Implications for Conservation
The study’s findings are significant because greater gliders are endangered and depend on continuous tree cover to travel and forage for eucalyptus leaves. Gaps created by logging or infrastructure development could hinder their movement. Dr Benjamin Wagner, an expert in greater glider habitats at the University of Melbourne who was not involved in the study, said the research has practical conservation implications.
“It means that disturbances to their habitat or habitat loss might be more severe than we thought,” Wagner said. In fragmented or less dense forests, there are more gaps to cross. “The vantage tree and the one that’s the target have to be closer together than we thought before. In a continuous forest that’s probably not so much of an issue, but it becomes an issue for them in scenarios where there are gaps to cross, like roads and maybe clearings from previous fires or timber harvesting.”
Comparison with Other Gliding Marsupials
Australia is home to several gliding marsupial species. The yellow-bellied glider is the most aerodynamic, covering an average of 40 metres and observed cruising up to 145 metres. In contrast, squirrel gliders typically sail about 12 metres. The 1941 paper that reported 100-metre glides for greater gliders may have been a case of mistaken identity, likely referring to a yellow-bellied glider.
