This glider has a yellow belly and a shriek that can be heard from 500m away
THE NEXT TIME you’re camping out in the bush and hear a loud shriek, rounded off with a deep, throaty gurgle, do not be alarmed. You could be hearing the distinctive sound of the yellow-bellied glider (Petaurus australis), an endangered sub-species of glider.
Often found soaring between the trees of tall eucalypt forests from south- eastern Queensland down to South Australia, the yellow-bellied glider is a medium-sized nocturnal marsupial with a distinctive buttermilk-coloured belly.
Of the six gliding marsupials found in Australia, the yellow-bellied glider is the most vocal, with its calls consisting of loud shrieks, whirring moans, gurgles, chirps and clicks.
These distinctive, piercing noises, which can be heard from up to 500m away, aren’t distress calls, but simply gliders communicating with their mates.
Their loud noises are also pretty good at scaring away predators like foxes, feral cats and owls, and of course, many a bush camper.
Queensland-based photographer Matt Wright uses their loud calls to locate the glider.
“The first method I use to find yellow-bellied gliders is spotlighting and trying to catch eye shine. The second one is listening to their calls, as they are a communal species, there are multiple in the same area and they’re often vocal.”
The loud vocals of the yellow-bellied glider. (Supplied: Matt Wright)
Home among the gum trees
Living in groups of up to six, yellow-bellied gliders require a large home range where they can freely soar from tree to tree.
Preferring the smooth bark trunks and flaky bases of the rose gum tree— a type of eucalypt—they depend on the natural hollows in the trees for shelter.
With glides of over 100m recorded, each glider may travel up to two kilometres away from their den tree each night in search of food.
Matt says, in his experience, the gliders aren’t a shy species.
“They are more energetic than the greater gliders who usually just sit there looking back at you. This has to do with their diet as greater gliders eat the same as a koala and yellow bellied-gliders are on a sugar based diet primarily.”
And they definitely need the extra energy. Intensely territorial, protecting their home among the gum trees is no easy feat as their range can extend from 25 to a massive 120ha.
Yellow-bellied gliders are notoriously picky eaters.
While they may consume a variety of foods, like insects and nectar, what intrigues scientists most are their habits for tapping tree sap.
All year round gliders use their lower teeth to extract sap from a number of particular species of eucalypt trees, leaving a distinctive V-shaped incision on the tree trunk.
Peculiarly however, gliders will only use a single tree located within a group of similar trees for tapping sap, self-limiting their own food supply.
Scientists argue that their fussy eating habits are due to the tree sap flowing at faster or slower rates at different elevations.
The challenges ahead
Listed as Vulnerable under the NSW Threatened Species Conservation Act 1995, the yellow-bellied glider requires a specific set of resources for survival.
Because the gliders only live and feed on specific species of gum tree, and are picky about which ones they choose for sap tapping, their habitats and food sources are under constant threat.
Land clearing, changes in forest type (due to fire regimes and climate change) and logging has further isolated the areas in which the yellow-bellied glider can survive.
In an attempt to combat the endangered status of these gliders, the New South Wales Government has compiled an action list to help protect the rare marsupial.
This list includes protecting high quality habitat, undertaking revegetation and limiting clearings to allow gliders to move freely. Due to small population numbers, it is difficult to gauge whether these measures are helping to improve the status of yellow-bellied gliders.
Taronga Zoo Keeper Wendy Gleen explained Australians can help to preserve this endangered species by planting native trees and shrubs in their backyards. These small undertakings create wildlife corridors which assist gliders’ movement to feeding trees
Through more research, awareness and the implementation of conservation measures, with any luck yellow-bellied gliders will be startling campers for many years to come.