About this publication
Gliding possums
Yellow-bellied glider
September 2002
Gliding possums are marsupials. There are five species in New South Wales:
- feathertail gliders
- sugar gliders
- squirrel gliders
- yellow-bellied gliders
- greater gliders.
In size, they range from only 7 cm long in the body (feathertail gliders) to almost cat-sized (greater gliders).
Where do they live?
Gliders generally live in a wide variety of eucalypt forests, most of which line the east coast and ranges of Australia. Sugar gliders have the widest distribution, as they can stand a greater variation in climate than the other species. They can be found in many different habitats, from the tropical parts of the Northern Territory to the cooler areas of Tasmania. Yellow-bellied gliders, on the other hand, are restricted to rich forest ecosystems that provide a continual supply of food.
Gliders usually make their nests in tree hollows, which they line with dry leaves. Some species, particularly the greater glider, mark out their territory by using scent glands. They rub the gland against the trees to warn off intruders.
How do they glide?
A gliding possum has a 'gliding membrane' - a thin sheet of skin which stretches between its forepaws and its ankles. When it leaps from a branch, its outspread limbs extend the membrane, allowing the animal to glide from tree to tree. At first the leap is downwards, but as the animal increases speed, the angle of flight flattens out. With its long, well-furred tail acting as a rudder, the glider can steer towards its next tree. Then, just before landing, it uses its tail to bring it into a 'nose up' position (much like an aircraft landing). Feet stretched out in front, it is ready to grasp the tree trunk on which it will land.
The yellow-bellied glider can cover distances of up to 140 metres in one leap. The sugar glider and squirrel glider can reach about 50 metres.
What do they eat?
Gliders feed at night. Their diet includes nectar, pollen, insects and the sap of certain eucalypt or wattle trees (in collecting eucalypt sap, yellow-bellied gliders leave distinctive 'v'-shaped notches on trees). The greater glider, however, feeds almost entirely on eucalypt leaves.
Growing up
The greater glider is the only gliding possum that doesn't live in a family or social group. These animals only come together for mating, and usually only one young is born. Other gliders have one or two at a time, although the feathertail glider can have a litter of up to four.
A naked, newborn glider (also called a neonate - a term which applies to all newborn marsupials) would fit on your thumbnail. Following birth, it crawls through its mother's fur to her pouch, where it attaches itself to a teat. Here it is kept warm and nourished with milk. After about three or four months it will come out into the nest and, with the adults, search for food.
When the young are big enough to look after themselves, they will usually leave the family and set up a group or territory of their own. Some females may stay with the original group, but males are often forced to leave.
An uncertain future
Gliders are protected in NSW. The squirrel glider and the yellow-bellied glider are quite uncommon (they have been listed as vulnerable under the Threatened Species Conservation Act 1995), and are in need of special protection.
The greatest threat to gliders comes from the destruction and alteration of the forest habitats in which they live. Gliders need mature forests with lots of tree hollows to nest in. When forest is cleared they lose their home and food supply, and may become prey to other species such as owls, foxes and cats. The gliders are easy targets in cleared or opened-up areas.
The NPWS is protecting forests in national parks, but these form only a small part of the state. The future of gliders outside national parks and other wildlife protection areas is far from certain.