By Juliet Nagel
Geographic Range
Greater gliders are found along the eastern coast of the Australian mainland, from eastern Queensland to southern Victoria (Nowak, 1999; Troughton, 1966).
Biogeographic Regions:
australian 
(native ).
Habitat
Greater gliders are generally restricted to fairly expansive tall eucalyptus forests, and are never found in the rainforest (Grzimek, 1990). Patches of old growth must be at least 20 ha to sustain a population (Possingham, et al. 1994). Greater gliders are associated with high basal areas of over-story, and they need large patch sizes of old-growth forest. They are most often found in sites containing many trees with hollows. A single glider may use 4-18 den sites (Incoll et al., 2001; Lindenmayer et al., 1993).
These animals are found in the following types of habitat:
temperate .
Terrestrial Biomes:
forest .
Physical Description
(2.2 to 3.3 lbs; avg. 2.75 lbs)
(11.81 to 18.9 in; avg. 15.35 in)
Greater gliders are the largest of the gliding possums. Females have a well-developed pouch and two mammae. P. volans are about the size of a domestic cat, weighing 1-1.5 kg as adults. The head and body length is 300-480 mm and the tail is 450-550 mm long (Nowak, 1999). These marsupials have a short snout and large round ears covered by thick fur (Strahan, 1995). The patagium, which is also covered with fur, extends from the knee to the elbow, (unlike the Petauridae, in which it extends from the ankle to the wrist), giving the glider a triangular shape when in the air (Berra, 1998). The long, furred tail, which is not prehensile, is used as a rudder (Grzimek, 1972). Color varies more than that of any other marsupial. The very long, dense fur is typically brownish-black, but can range from pure black with a creamy underside, to dusky browns and grays, cinnamon, red, yellow, and completely white (Grzimek, 1972; Troughton,1966).
Some key physical features:
endothermic ; bilateral symmetry .
Reproduction
Breeding begins in March, and the young is born between April and June.
Males and females will normally share a den from the onset of breeding until the young emerge from the pouch (Strahan, 1995). Some males are monogamous while others are bigamous, although there is no paternal care given to the young (Nowak, 1999).
Mating systems:
monogamous ; polygynous .
Breeding season begins in March, and a single young is born between April and June. The offspring rides in the mother’s pouch until September, suckling on one of the two teats, then rides on the mother’s back until November or December. In January it reaches the age of independence. Sexually maturity is reached at two years of age. Until weaning, approximately half of the offspring produced are male. After the weaning period, the proportion of the population that is male drops precipitously to 39% (Hand, 1990; Tyndale-Biscoe and Smith, 1969).
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (internal ); viviparous .
As in all marsupials, the young are born highly altricial in most respects. Development must be completed in the mother's pouch, rather than in the uterus, as it is in placental mammals. The single offspring is nursed in the pouch until September, when the young glider emerges at 150 g to ride on its mother’s back. In November-December, when about 300 g, the young leaves its mother’s back and becomes more independent. In January, at about 600 g, the young is able to live independently. (Tyndale-Biscoe and Smith, 1969).
Parental investment:
altricial ; female parental care .
Lifespan/Longevity
[External Source: Max Planck Institute for Demographic Research]
Longevity may be up to 15 years in the wild (Nowak, 1999).
Behavior
Gliders are solitary arboreal animals, with a home range of 1-2.2 ha. Home ranges of females overlap, whereas males maintain separate territories (Incoll et al., 2001). They nest in hollows high up in both living and dead trees. The hollows are occasionally lined with strips of bark or layers of leaves (Troughton, 1966). P. volans may transport nesting material rolled-up in their tails (Nowak, 1999).
Greater gliders are clumsy and slow on the ground, but they are at home in the trees and in the air. During gliding, they bend their forearms, with the hands almost meeting in front of the chest (Grzimek, 1972; Nowak, 1999). They use their long, furred tail as a rudder (Troughton, 1966).
Greater gliders use their patagium as a blanket to reduce heat loss by wrapping it around themselves. On hot days, they will lick their fur to lose heat through evaporation (Grzimek, 1990).
Key behaviors:
nocturnal ; motile ; sedentary ; solitary ; territorial .
Food Habits
Greater gliders are folivores, feeding almost entirely on eucalyptus leaves that they break down with bacterial fermentation in an enlarged cecum (Berra, 1998; Lindenmayer et al., 1999; Possingham et al., 1994). This specialized diet means they are very difficult to keep in zoos (Grzimek, 1990). Greater gliders rarely need to drink (Strahan, 1995).
Plant Foods:
leaves.
Predation
- powerful owls (Ninox strenua)
- sooty owls (Tyto tenebricosa)
- dingos (Canis lupus dingo)
- red foxes (Vulpes vulpes)
Owls may represent the largest threat to gliders. Powerful owls and sooty owls both prey upon them. Dingos and introduced foxes also take P. volans. Because they are gliders, it is likely that they can escape predators by "flying" away.
Ecosystem Roles
The role of these gliders in the ecosystem has not been evaluated. However, they do eat eucalyptus leaves, maing the energy stored in those leaves available to their predators.
Economic Importance for Humans: Negative
Since greater gliders require large patches of old growth habitat (Possingham et al., 1994), their needs can conflict with those of humans who wish to cut the trees for timber.
Economic Importance for Humans: Positive
Although the fur is long and thick, it is rather loose and soft which makes it difficult to work with. Luckily for greater gliders, fur traders rarely wanted their skins (Strahan,1995).
Conservation Status
Although widespread and abundant in some areas, greater gliders are very sensitive to clear-cuts and fragmentation of their old-growth habitat. Their conservation is entirely dependent upon the responsible management of the old growth forests in which they live (Kavanaugh and Bamkin, 1995; Strahan, 1995). Tyndale-Biscoe and Smith (1969) showed that over 90% of gliders displaced by a clear-cut die rather than establish a new territory in suitable habitat nearby. Greater gliders may have difficulty migrating through unfavorable habitat for several reasons. They are specialist feeders, and only eat the leaves of some eucalyptus trees. They only carry limited quantities of body fat, and are likely to undergo rapid changes in body condition under adverse conditions, such as with dispersal. They are also very clumsy on the ground, and so have difficulty in crossing open tree-less areas (Lindenmayer et al., 1999).
Other Comments
Greater gliders were previously classified as Schoinobates volans until 1982, when the generic name was changed to Petauroides (Nowak,1999).
Contributors
Juliet Nagel (author), University of Wisconsin-Stevens Point.
Chris Yahnke (editor), University of Wisconsin Stevens Point.
