Squirrel gliders, Petaurus norfolcensis, are similar to sugar gliders, Petaurus breviceps, in general appearance, but are twice as large (Nowak 1999). They have more distinct facial markings, a longer face, and a bushier tail than P. breviceps (Suckling 1995). At times though, these two species can only be reliably distinguished by the larger molar teeth of P. norfolcensis (Smith 1979).
Squirrel gliders have pale grey fur on their dorsal surface, with a dark brown or black stripe down the middle (Barrett 1955). They possess a prehensile tail, an opposable hallux (Feldhamer 1999), and a long gliding membrane that extends from the outside of the forefoot to the ankle (Nowak 1999).
Squirrel gliders have long, sharp, diprotodont lower incisors. Their molars are bunodont, and they possess a total of 40 teeth (Feldhamer 1999).
Range mass: 190 to 300 g.
Habitat and Ecology
In south-eastern Australia, P. norfolcensis occupies dry sclerophyll forest and woodlands, but is absent from the dense coastal ranges. In northern New South Wales and Queensland it inhabits coastal forest and some wet forest areas that border rainforest (Suckling 1995).
In some habitats density of P. norfolcensis is as high as 3 individuals per hectare (Suckling 1995).
The squirrel glider is an omnivorous species. Typical foods in the diet of P. norfolcensis include insects (mainly beetles and caterpillars), acacia gum, sap from certain eucalypts, nectar, pollen, and the green seeds of the Golden Wattle (Nowak 1999). Nectar and pollen are the most important dietary items, but in the absence of these foods the squirrel glider will more heavily utilize sap and gum (Nowak 1999).
Life History and Behavior
Status: captivity: 11.9 years.
Lifespan, longevity, and ageing
The breeding season in P. norfolcensis occurs during June and July, with a gestation period that lasts slightly less than three weeks (Suckling 1995, Nowak 1999). During the breeding season, female P. norfolcensis exhibit a well-developed pouch (Nowak 1999) that is maintained through December (Smith 1979). This pouch opens anteriorly (Feldhamer 1999) and has four nipples (Smith 1979). In the months of January through May, the female's pouch becomes small and dry, indicating anestrus. Male P. norfolcensis produce sperm throughout the year (Smith 1979).
The typical litter consists of one or two young (Nowak 1999). These young stay in the mother's pouch for approximately 70 days after parturition. The young are fully furred at approximately 76 days and eyes open at 84-85 days (Smith 1979). The young will remain in the nest for another 40-50 days after emerging from the pouch. At the age of 110-120 days, the young of P. norfolcensis begin to venture out and forage with their mother (Suckling 1995).
Average gestation period: 20 days.
Average number of offspring: 1.5.
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1996Lower Risk/near threatened(Baillie and Groombridge 1996)
The squirrel glider may be endangered in the southern part of its range, due to the mass clearing of woodland for agriculture and forest operations. This impacts P. norfolcensis by decreasing the abundance of tree hollows which it relies on for nesting sites (Suckling 1995).
Lunney (1987) found that the effects of logging, especially when compounded with exposure to drought and fire, have a negative impact on glider species, reducing the habitability of an area. Deep gullies, unaffected by logging, were found to be crucial refuges for gliders. It is recommended that these gullies be maintained and protected in order to conserve habitat for all species of gliders.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
This species' home range extends from Bordertown near the South Australian/Victorian Border through south-eastern Australia to northern Queensland. This species was thought to be extinct in South Australia since 1939 until a genetic test confirmed their inhabitance in this area.
The Squirrel Glider lives in south-eastern Australia in the dry sclerophyll forest and woodlands. In Queensland, however, they occupy a wetter eucalypt forest.
The glider will make a den in the hollow tree and line it with leaves. Here it will sleep and usually lives in groups of one male, 2 females, and offspring.
Like most of the wrist-winged gliders, the Squirrel Glider is endemic to Australia. It is about twice the size of the related Sugar Glider (P. breviceps). Its body is 18–23 cm long and its tail measures at 22–33 cm long. It weighs about 230g or 0.5 lbs. They have blue-grey or brown-grey fur on their back and a white belly. The end of their tail is black and they have ha black stripe from their eyes to the mid-back. They have a flying membrane that extends from their 5th front toe to the back of their foot on both sides. When they glide their prehensile tail can act as a rudder, allowing them to steer which direction they want to go. They can glide up to 50m from tree to tree. They tend not to glide in captivity.
The breeding season is between June and January. The gestation/pregnancy of a female is 18 days. The litter sizes are usually one to two offspring a year. The offspring will immediately crawl to the mother's marsupium and anchor itself to a teat were it will stay for about 3 months. The mother will wean off her offspring around 4 months were they stay in the den. The offspring become independent at 10 months and go off on their own. The life expectancy is 4–6 years.
The Squirrel Glider eats mostly fruit and insects. It also feeds on tree sap, mainly Eucalypt or Red Bloodwood trees. In order to get the sap the Squirrel glider will pierce the trunk of the tree causing sap to flow out of it. It also eats pollen, nectar, leaves, and bark.
The species is threatened by humans clearing and breaking up their habitats. It also has predators of dogs, cats, foxes, and owls. This causes the species to be put on the Near Threatened list, meaning it is close to being a threatened species.
The Squirrel Glider's closest relatives come from the same genus, Petaurus and they include the Sugar Glider (P. breviceps) , Mahogany glider (P. gracilis), Northern glider(P. abidi), Biak Glider(P. biacensis) and Yellow-Bellied glider (P. australis). It is not yet known which species the gliders diverged from. The Squirrel Glider most likely evolved from a marsupial like a possum that had membranes for gliding. Other animals that have this same ancestor include Striped possum and Leadbeaters possum.
Squirrel Gliders are often mistaken for flying squirrels of North America. These two species aren’t related at all. The Flying Squirrel is a placental mammal and the Squirrel glider is a marsupial like koalas and kangaroos. Both have an adaptation for tree living – Patagia. This is the skin that extends from their front to hind legs allowing them to glide between the trees avoiding predators they might come into contact with on the ground. Because these animals are distantly related we call these characteristics analogous.
Squirrel gliders are able to curl their tails around branches to hold on. This feature is homologous to the ring tail possum (order of Diprodontia) which use their tail as an extra limb to grab hold of trees. It is longer but the squirrel gliders tail is bushier.
- Groves, C. P. (2005). In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press. p. 55. OCLC 62265494. ISBN 0-801-88221-4.
- Winter, J., Lunney, D., Denny, M., Burnett, S. & Menkhorst, P. (2008). Petaurus norfolcensis. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 28 December 2008. Database entry includes justification for why this species is of least concern
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