Squirrel Glider

Squirrel Gliders are small possums that have distinctive membranes of skin, stretching between their front and hind legs, that enable them to glide with ease through the air.

Identification

Squirrel Gliders, Petaurus norfolcensis, are often mistaken for the more common Sugar Glider, Petaurus breviceps.It is,in fact, the larger of the two with a long bushy tail as wide as the body at the base and longer, pointed face.The fur colour is usually a brown-grey with a darker stripe from the forehead and down the back. The underside of the body can vary from a pale grey to creamy yellow. The broad, bushy tail while similar in colour to the upper body, has a distinctive dark tip.

Habitat

The Squirrel Glider has a preference for wet and dry sclerophyll forests and woodlands. While they are often found in the drier forest areas, in some areas of Queensland they prefer wetter forest areas bordering on rainforest. The most common vegetation areas where they can be found are usually charactized by one or more species of iron-barked eucalypts.

Distribution

When the species was first described in 1792, it was given the species name norfolcensis,named in the belief that the Squirrel Glider originated from Norfolk Island. This was incorrect.Being aboreal, the Squirrel Glider can be found along the Great Dividing Range from central Cape York, Queensland south to central Victoria with some isolated pockets in eastern South Australia.

Feeding and diet

Squirrel Gliders are omnivores who feed at night.They live primarily on insects (mainly catepillars,beetles and stick insects) but also on pollen and nectar (mostly from eucalypts). Plant exudates such as sap or resin from wattle and eucalypt trees, are similarly an important part of a Squirrel Glider's diet.Obtaining food from any one of these sources usually depends on seasonal influences.

Other behaviours and adaptations

Being arboreal, Squirrel gliders are very adept at climbing.They are rarely found on the ground and are able to glide from limb to limb of trees using the membranes of skin that stretches between their front and back legs.They have been observed to glide up to 100 metres with the assistance of a downhill slope and up to 50 metres over flatter terrain. To steer and maintain stability, the curvature of either the left or right membrane can be varied. As they approach to land, Squirrel Gliders bring their hind legs closer to their body, make an upward swoop and land on some bark on all fours.

Squirrel Gliders take shelter in tree hollows during the day and will come out only at night.Large light sensitive eyes allow for increased night vision.Movement along branches is in small bounds. They have been known to freeze or hide when detected by a spotlight.

Communication

To communicate, Squirrel Gliders are known to utter a soft nasal gutteral call, interspersed with gurgling chatter. To raise the alarm when disturbed by predators, often a loud yip can be heard.

Life history cycle

In south eastern Australia breeding usually begins in August with each female producing two young. The young newborns will remain in the pouch for about seventy days. Here they attach to the mother's teat being nourished with their mother's milk. After this period they are depositied in the nest for another month or so and forage for food with the adults.By four months of age, the young Squirrel Gliders are ready to leave the nest and establish their own territories. Some females may stay with the group but usually males will leave.

Breeding behaviours

The ability to breed is usually reached around 12 months of age. For males, a scent gland is present on the top of their head. It is found in the middle of the dark strip of fur that extends from the nose to the middle of the back.

Nests are bowl-shaped, lined with leaves and found in tree hollows.

A typical family group consists of one mature male (over two years of age) and one or two mature females with their offspring. The numbers can increase to up to five adults with the inclusion of one or two young males (not more than two years old) to the group.In total there can be up to ten members in a family group.

Conservation status

Squirrel Gliders are listed as: vulnerable in NSW, threatened in Victoria, endangered in South Australia and common in Queensland.

The main threats facing Squirrel Gliders today stem from the fragmentation of their habitat. Coupled with this the loss of trees with suitable hollows for nesting and the loss of food souces contained in the flowering mid storey shrubs,has compounded threats to their habitats.

Barbed wire fences have also contributed to their demise especially when gliding.Additionally attacks by feral cats have accounted for high losses in Squirrel Glider numbers. If you do own a cat, please ensure it is kept inside at night or is fitted with some large bells to allow possums to escape from these hunters.

References

• Strahan R: The Mammals of Australia. Reed New Holland 1995.
• Menkhorst P, Knight F: A Field Guide to the Mammals of Australia. Oxford University Press 2004.
• Cronin L: Key Guide to Australian Mammals Reed 1991.
• NSW National Parks and Wildlife Service: Gliding Possums.
• Smith A, Hume I: Possums and Gliders. Surrey Beatty&Sons Pty Ltd 1985.