Dr Ana Gracanin describes the greater glider as “one of the most interesting and unique” species in Australia. Photo: David Gallan.
A case of mistaken identity gave rise to a false impression of how far greater gliders can jump, researchers have revealed.
Dr Ana Gracanin, from the Fenner School of Environment and Society at the Australian National University, led the team that made the discovery.
In what’s believed to be a first, they studied not only how far the possum can jump, but also how much height they drop during a jump from one tree to another.
“Up until this point, there hadn’t been any data or any record about [their jumping distance],” she says.
“We just had a few observations from a couple of people and one of those observations was actually from the 1940s and that observation described a 100-metre glide.”
“But when we read back through all the papers … the description is actually referring to a completely different species.
While the other animal (suspected of being the yellow-bellied glider) caught researchers’ attention in the 1940s study as it “screamed and gurgled and hissed”, the southern greater glider slipped under the radar.
Dr Gracanin says it threw doubt on the long-held belief that the latter kind of glider can really jump 100 m.
To find out how far they actually can jump, Dr Gracanin and her team set up at sites across Monga National Park, Tallaganda National Park (and an adjacent private property), Tallaganda State Forest and Mount Lindsey.
During long spring and summer nights, they bunkered down in the forest locations to see what the greater glider could do.
The researchers tracked southern greater gliders over 41 jumps, using infrared cameras, thermal imaging and their phones to record the jumps.
Two tripod-mounted laser pointers were used to pinpoint where the greater gliders launched from and landed.
Their results dash the belief that the marsupial can make 100 m jumps – after all, the longest glide recorded was just under 50 m.
“They’re called the greatest glider – and maybe they’re not the greatest at gliding, but they are the greatest [in terms of] their size,” Dr Gracanin says.
“They’re the largest marsupial gliding species in Australia.”
The team also found the animal launched from an average height of 22 m and travelled an average horizontal distance of 19 m before descending at an average angle of 43.5 degrees.
The researchers tracked southern greater gliders over 41 jumps. Image: Supplied.
For Dr Gracanin, the chance to see them jump “never ever gets old”, with the study giving her time to learn how they position themselves to jump.
“They tap their paw on the little branch that they’re on – in trepidation, almost – and they tap their paw and then they swing their body forwards and backwards.
“After that, they often will then launch up into the air.”
They also found that the southern greater glider has different ways of jumping – some “dive bomb”, while others launch themselves forward.
“It was a great team effort and it felt like something in a National Geographic documentary, just being able to witness these amazing glides,” she says.
“It is such a spectacle.”
The species is listed as endangered by both the NSW and Federal Governments amid significant population declines.
They have also been hit by habitat loss, including through land clearing and the Black Summer bushfires.
“These findings are really important for conservation … The species needs to be able to move between areas to disperse and to help populations continue.
“If they become small and isolated, they’re at greater risk of extinction. Making sure that there’s enough canopy connectivity … or [other] structures in place is really important.”
Even though the team’s findings indicate that the gliders can’t jump as far as we thought, Dr Gracanin believes the greater glider could reclaim its 100-metre jumping record – eventually.
“I’m sure that with more study, more research, we can really understand their maximum capacity for gliding – because in taller forests, it’s likely that they can glide further.”
