Sugar Glider

Echuca Moama Wildlife

The Sugar Glider (Petaurus breviceps) is a small gliding possum native to eastern and northern mainland Australia, New Guinea, and the Bismarck Archipelago, and introduced to Tasmania.

The Sugar Glider is around 16 to 21 cm (6.3 to 7.5 inches) in length, with a tail almost as long as the body and almost as thick as a human thumb, and weighs between 90 and 150 grams (3 to 5.3 oz). The fur is generally pearl grey, with black and cream patches on the underbelly and black or grey ears. Other colour variations include leucistic and albino recessive traits. The tail tapers only moderately and the last quarter of it is black, often with a dark tip. The muzzle is short and rounded. Northern forms tend to be brown coloured rather than grey and, as predicted by Bergmann's Rule, smaller.

The most distinctive features of its anatomy, however, are the twin skin membranes called patagia which extend from the fifth finger of the forelimb back to the first toe of the hind foot. These are inconspicuous when the Sugar Glider is at rest – it merely looks a little flabby, as though it had lost a lot of weight recently – but immediately obvious when it takes flight. The membranes are used to glide between trees: when fully extended they form an aerodynamic surface the size of a large handkerchief.

The gliding membranes are primarily used as an efficient way to get to food resources. They may also, as a secondary function, help the Sugar Glider escape predators like goannas, introduced foxes and cats, and the marsupial carnivores, such as quolls, the Kowari, mulgaras, and antechinuses that foxes, cats, and dingos largely supplanted. The ability to glide from tree to tree is clearly of little value with regard to the Sugar Glider's avian predators, however, in particular owls and kookaburras.

Although its aerial adaptation looks rather clumsy in comparison to the highly specialised limbs of birds and bats, the Sugar Glider can glide for a surprisingly long distance — flights have been measured at over 50 metres (55 yd) — and steer effectively by curving one patagium or the other. It uses its hind legs to thrust powerfully away from a tree, and when about 3 metres (3 yd) from the destination tree trunk, brings its hind legs up close to the body and swoops upwards to make contact with all four limbs together.

The Sugar Glider can occupy any area where there are tree hollows for shelter and sufficient food. Its diet varies considerably with both geography and the changing seasons, but the main items are the sap of acacias and certain Eucalyptus, nectar, pollen, and arthropods. It is difficult to see in the wild, being small, wary, and nocturnal, but a sure sign of its presence is the stripping of bark and tooth marks left in the soft, green shoots of acacia trees.

In suitable habitats it is common, often reaching densities of 1 per 1,000 square metres provided that there are tree hollows available for shelter. It lives in groups of up to seven adults, plus the current season's young, all sharing a nest and defending their territory. Adult males mark the territory with saliva and with a scent produced by separate glands on the forehead and chest, and also mark members of the group with this scent. Visitors which lack the appropriate scent marking are expelled violently. The dominant male mates more frequently with the female of the group than the other males, and does most of the scent marking. When an adult member of the group dies, it is normally replaced either by one of the group's own offspring if female, but by an outsider if male.

In the more temperate south, breeding starts in mid-winter (June or July). In the north, there seems to be no particular breeding season. Two young per female is typical; they remain in the pouch for about 70 days, and after leaving it stays inside the nest for another 40 or 50 days, then begin to forage outside, usually under the care of the mother. The young are normally ejected from the group territory at 7 to 10 months of age. Sometimes they form new groups if an area is vacant, but competition for territory is fierce and not many survive the first months of independent life. In captivity, they may live up to fifteen years.