15 Dec 2022

THE GREATNESS OF GREATER GLIDERS

BREAKING NEWS: Logging has been temporarily suspended in Tallaganda State Forest after an Endangered greater glider was found deceased just 50 metres from the logging site. 

We only have a small window to secure permanent protection for this area - one of the last places of refuge for greater gliders. Take action now - sign the petition or donate.

There is nothing greater than an incredibly furry, triangular-shaped “flying possum” (that is not really a possum) to inspire a fascinating read from lifelong nature lover, observer, and story purveyor David Waterhouse.

A starry night in late February. I was one of two forward scouts on infantry patrol. We plodded warily and wearily along one of many sandstone ridges, somewhere near the Colo River off the Windsor-Singleton road. The rest of our platoon were shadowy figures somewhere behind us.

Without any warning, an object swept past us, emitting a loud, tremulous shriek. A triangular-shaped creature with a long, thick tail landed with an upward swoop, to thunk on the base of a stringybark in front of us. It quickly scrambled up the tree in a series of quick, jerky movements and disappeared into the darkness.

It was a greater glider. I had never seen one in the wild before. ‘What the hell was that?’ said Geoff, the other forward scout. I froze and stared in fascination. He stared in bewilderment. I told him it was just a kind of ‘flying possum’. He didn’t know that such things existed. His camouflaged face relaxed on learning that it was quite harmless. Seconds earlier, he looked as if he’d just seen an unearthly apparition of some kind.

Back at base, the rest of the platoon heard of the incident and laughed when Geoff told them that he almost soiled his jungle greens; or words to that effect.

Years later, I became acquainted with greater gliders again. They could be seen occasionally high in the treetops, where they sought their staple food of eucalyptus leaves, in the East Chichester State Forest near Dungog. I never saw one glide, but, in a spotlight they could be seen clearly and not as ghostly shadows in the dark, as in my army days.

By scanning the tree canopy from the flatbed of a ute, the spotlight would sooner or later pick out a pair of eyes which glowed red in the beam of light. Most of the gliders we saw had thick, brown fur, but some were almost black or grey in colour. We never saw the beautiful, white-furred variety which is most likely to be encountered on the South Coast of New South Wales.

Greater Glider spotted in the Blue Mountains= NSW
© Dr Peter Smith

What sticks in the mind about their appearance are their rounded ears which were so furry they seemed to be muffed. Their tails too, when visible through the foliage, were luxuriously furred so they resembled miniature bell ropes dangling from their bodies.

Sometimes, if one was seen side-on, along a branch, its flanks were not straight, but waved, the folded ‘flying’ membrane giving the impression of a mammal resting on a rumpled rug or small carpet up in its treetop home. When fully outstretched, the gliding membrane is furred, not naked skin, as is the case in bats. The taut membrane of this kind of glider extends from the elbows to the ankles, and presents the observer with the impression of a triangle being steered by a long, thick rudder. In other glider species, the membrane in flight appears as a flattened sheet because it extends from wrist to ankle.

Greater glider (Petauroides volans) gliding in Logan= Queensland
© Sami Raines

Unlike sugar gliders, greater gliders do not eat insects. They feed, instead, on leaves and perhaps blossom of eucalypts of various kinds. In some forests, they may also feed on other leaves, such as the needles of Casuarinas.

They sleep in tree hollows during the day. They are said to be able to glide up to a hundred metres or more between scattered trees. A forester of the Dungog district told me that in thickly forested areas, greater gliders may not need to glide at all. They will merely clamber about from one treetop to another if the crowns are so close they adjoin. The same person said that sometimes one will move across open ground to reach an isolated food tree, in an awkward, trundling run.

I assumed that they fed more or less throughout the night, but there are those who have made studies of these gliders who have observed them re-enter their hollows in the dark and remain in them for some time before venturing out for another feed.

In suburbia, as I know myself, Australia’s largest owl, the powerful owl, preys largely upon ring-tailed possums, but in some areas, especially mountain forests, greater gliders form the main part of its diet. Like the ring-tails (to which greater gliders are closely related), they are snatched from their tree perches and carried off to be eaten at leisure. Powerful owls are most likely their only predator, although it is possible that goannas may take them from their hollows, as they sometimes do with sugar gliders. Almost full-grown greater gliders, after leaving their home hollows to seek new ones, may be easy prey for diurnal raptors.

Up on the Atherton Tableland in North Queensland, I once spoke to a farmer who allowed me onto his property. On the back block grew scattered eucalypts. A barbed wire fence ran between some of them. He showed me the spot where he had found a greater glider caught by its gliding membrane on a barb cluster. I had heard of similar unfortunate incidents in the southern states, where a fox may find the victim and drag it off to its den.

Lately, conservation organisations have expressed concern that due to wildfires devastating large areas and landclearing, more and more habitat for the greater glider is being lost or degraded. It appears to be in decline in places where it was once quite common.

This native animal, like a lot of other marsupials, is not seen as an iconic species like the koala or the bilby, and few know of its existence. This, to me at least, is a great pity for they are interesting and engaging creatures.

Whether they are still common where I first encountered one west of the Putty Road, I do not know. Much of the area where we sweated, dug trenches and patrolled has now become part of the NSW National Park Service’s domain, but huge and extensive bushfires have since ravaged most of it.

I only hope that some greater gliders still shriek and parachute between the tree trunks there, with their long, furry tails steering them through the night sky.

Greater glider in a patch of old growth forest in Munruben, Logan City, south of Brisbane
Greater glider in a patch of old growth forest in Munruben, Logan City, south of Brisbane © Josh Bowell

Greater glider habitat has been through turmoil in the last few years with bushfires, floods and tree-clearing threatening their homes. Research estimates that the 2019-2020 bushfires resulted in a 60% decline in the greater glider population of the Blue Mountains. WWF is in partnership with Greening Australia and Australian National University to help protect and restore greater glider habitat.

There is an incredible team of women installing nesting boxes, conducting biannual research and learning more about greater glider habitat to continue advocating for their protection.

Whilst David Waterhouse is a generous monthly contributor, he has also decided to continue his support by leaving a gift in his Will to WWF. If you would like to support conservation initiatives into the future like David, get in touch with us at giftsinwills@wwf.org.au.