The Yellow-bellied Glider (Pretaurus australis) is the largest member of the Petaurus group of gliders – it’s like a large, highly active version of the smaller and more common Sugar Glider (Petaurus breviceps). It weighs considerably less than the more distantly related Greater Glider (Petauroides volans) and has long fur, giving it a fluffy appearance; some people may know it as the Fluffy Glider.
It has a scattered distribution across the State, with relatively fewer records in north-east Victoria, than in the species’ stronghold of East Gippsland and the Central Highlands.
The tall, wet eucalypt forests of the Strathbogie Ranges are separated from the forests of the Central Highlands and the north-east by the valleys of the Goulburn River and the Broken River, respectively. Until recently, Yellow-bellied Gliders were considered to be absent from the Strathbogie Ranges.
In 1993 a solitary, large glider was observed high in a tree in the Tourour district of the Strathbogie State Forest. It had a two-tone colouration and remained motionless for several minutes, perched on the end of a dead limb; it did not vocalize. At the time, the animal was considered to be a Yellow-bellied Glider (D. Robinson, pers. communication 1997) and this record is the more easterly of the dots in the Strathbogies on the map, above.
In hindsight and in discussion with the original observer, the animal’s behaviour (and colouration) suggests the animal to have been a Greater Glider (possibly a ‘grey phase’ individual), rather than a Yellow-bellied Glider. Greater Gliders commonly perch on exposed branches and may remain motionless for many minutes (surprising really, as they are a favoured prey item of the Poweful Owl). Yellow-bellied Gliders are usually in constant motion. Rarely staying still, they move through the forest canopy as a family group, vocalizing to keep in contact with each other. It’s often very difficult to get a good look at them, because they rarely prop for long enough to find them with a spotlight and get binoculars onto them.
In 1996, during one of several arboreal mammal surveys being conducted by students from Goulburn Ovens TAFE (with me, Bertram Lobert), Yellow-bellied Gliders were recorded from an extensive stand of Mountain Swamp Gum (Eucalyptus camphora) at the base of Mt. Barranhet, in the Toorour district of the Strathbogie State Forest. The first indication of their presence came while spotlighting in messmate forest, far above the creek/swamp; we heard the faint, yet unmistakable gurgling-shriek of several Yellow-bellied Gliders from the swamp below.
After moving down to the swamp, we heard three individuals, calling and foraging amongst the loose bark in the Mountain Swamp Gums. These individuals moved around us as a loose group, calling softly to each other, while we stood in the darkness and listened. During this time, the shriek-gurgle of a glider was heard some distance to our west, on the easterly slope of Mt Barrenhet, though we didn’t investigate further, choosing to remain with the animals in the Mountain Swamp Gums. We then attempted to locate the animals in the swamp with 100 W, 12 V spotlights, only to hear them move through the trees away from us. Despite us remaining on-site over the next hour, the animals were not heard or seen again.
Several months later, a stand of mature Messmate Stringybark (Eucalyptus obliqua), adjacent to the Mountain Swamp Gum habitat, was logged. The coupe had contained many large, old, hollow-bearing trees.
Despite several surveys in the same area over the next 12 months, as well as spotlighting and listening for calls in nearby suitable habitat in the many years since 1996, no Yellow-bellied Gliders have since been recorded anywhere in the Strathbogie Ranges.
These observations are the only confirmed Yellow-bellied Glider records from the Strathbogie Ranges. Did the logging of that coupe stand wipe out this family of gliders? Are Yellow-bellied Gliders now extinct in the Strathbogie Ranges? Has anyone else seen this species in the Strathbogie Ranges?
Fair point Val. For extended observations, red filters are important. Though personally, I find first detection much better with a white light, both because penetration of the canopy is better in tall forest and also because, to my eye, there is better visual contrast in the beam. Still, a flip-down or click-on red filter is pretty good for spotlighting where the canopy isn’t high. All the best. Bert.
Thanks Bert. I hope all these observers are using red filters on their spotlights!
Hi Val, Observers per se aren’t that big a threat to yellow-bellied Gliders. There are plenty of places up and down the east coast where these gliders are regularly monitored by observers. They are very agile and active and can pretty easily avoid observers if they feel threatened. Of course, its best to be conservative, so the less disturbance the better.
It sounds as though the YB Glider is very shy & the presence of observers may drive it away. A bit like the situation with the Night Parrot. Best left undisturbed, one thinks.