Squirrel Glider

BIRD: linking the biodiversity community

Category: Marsupials

The Squirrel Glider (Petaurus norfolcensis) is considerably larger and less common than the well-known Sugar Glider, but very closely related. Adults are around 18 to 23 cm in length, with a slightly longer tail, and weigh between 190 and 300 grams. The fur is generally pearl grey, with black and cream patches at the base of the pink ears, and a white or light cream belly. The large, bushy tail is grey, darker near the tip.

Like the Sugar Glider, it is native to eastern mainland Australia, although the larger species is not found in the far north of the continent. It is sparsely distributed through the dry sclerophyll forests and woodlands of eastern Australia, from the Grampians in the southwest, through the box-ironbark country of central and eastern Victoria, the inland slopes of southern NSW, and up the coast and hinterland as far north as Cairns and as far inland as Coonabarabran. It generally avoids closed forest and rainforest.

The Squirrel Glider feeds on acacia and eucalypt sap, nectar, pollen, flowers, caterpillars, beetles and other insects, and the green seeds of the Golden Wattle. It forages at a variety of heights, from the crowns to shrubby understory. It is a sure-footed and agile climber, and can glide as far as 50 metres between trees.

Squirrel Gliders live in family groups of 2 to as many as 10 individuals, but typically comprising an adult male, one or more adult females, and their offspring of the season. Groups occupy a home range estimated at between 0.65 and 8.55ha, largely depending on habitat quality. They are nocturnal and require tree hollows to shelter in through the day, both to escape predators and to maintain body temperature during extremes of heat and cold. Like Sugar Gliders, Squirrel Gliders line hollows with eucalypt leaves, adding more leaves in colder weather, and huddle together for warmth.

Habitat requirements are more strict than those of the Sugar Glider: Squirrel Gliders need a mix of eucalypts and acacias, and also favour banksias. At least one favoured tree species must flower in winter and one or more of the eucalypts needs to be smooth-barked, both to provide a greater variety of insect food and because smooth-barked eucalypts tend to harbour more hollows.

Breeding can take place at any time of year but depends of food availability. Females can have two litters a year in good conditions, more commonly one. The young leave the nest at around 6 months but despite aggression from the dominant male may remain in the general area for about another year before finding a territory of their own. Mortality during the dispersion phase is high but once established, individuals can survive for up to six years,

Although they are around twice the weight of a Sugar Glider, Squirrel Gliders are very similar in most respects (it is worth reading Sugar Glider as well, as most of the information there applies equally to the larger species) and although they are not known to interbreed in the wild, they will in captivity, producing fertile offspring. In general, where the species overlap, the larger Squirrel Gliders usurp the prime habitat, leaving the more marginal territories to the smaller Sugar Gliders. The relative rarity of the Squirrel Glider in recent times is thus a good indicator of the scarcity of remaining quality habitat.