Lucky me … while camping in the Watagan Mountains south of Newcastle, New South Wales, I was visited in the middle of a cold, calm night by Yellow-bellied Gliders, Petaurus australis. Even more amazingly, they sounded off just few feet from my microphone, letting loose with outrageous squealing ducky growls quite unlike any animal sound I have ever heard.
Squealing growls of Yellow-bellied Gliders, recorded in the middle of the night in the Watagan Mountains near Cooranbong, New South Wales, Australia. 8 October 2012. (silent intervals between calls have been reduced)
Adapted for gliding from tree to to tree, these extraordinary marsupials (including other species of Petaurus) are an excellent example of convergent evolution, often being compared to our own two species of flying squirrels, Glaucomys volans (Eastern Flying Squirrel) and Glaucomys sabrinus (Northern Flying Squirrel). They are able to glide with the help of a thin membrane of furry skin that extends from the elbow of each foreleg to the knee of each hind leg. When leaping, the legs are extended, allowing for downward glides of 200 feet or longer.
The Yellow-bellied Glider is about the size of a small rabbit, and is the largest of Australia’s various Petaurus gliders. Living in family groups, the species is quite vocal, as I discovered myself by spending nights in the forest. When Carl and I heard one growl during our first evening in the Watagan’s, we had no idea what we were hearing, though we presumed the source to be a marsupial mammal of some sort.
Feeding on nectar, pollen, and insects, the Yellow-bellied is also known to gnaw V-shaped incisions in the bark of trees in order to promote the flow of sap. The Yellow-bellied’s range is restricted to a narrow band of Eucalyptus forest extending from Queensland to Victoria. Uncommon to rare in many areas, it is considered threatened over much of its range (though it appears to be quite common in the Watagans).