Petaurus gracilis
mahogany glider

Mahogany gliders, Petaurus gracilis, are native to Northern Queensland, Australia. They are currently found between Toomulla and Tully and about 40 km inland. ("ARKive", 2010; "Mahogany Glider", 2010; Dettmann, et al., 1995; Jackson, 2000a)

Mahogany gliders live in highly fragmented open Eucalyptus woodlands as well as swampy coastal lowlands of Northern Australia. They are found at elevations between 20 and 120 m. They are generally a solitary species, preferring to sleep in the hollows of trees either alone or with one individual of the opposite sex. ("ARKive", 2010; "Mahogany Glider", 2010; Jackson, 2000b)

Mahogany gliders are the second largest species of glider in Australia and are approximately 600 mm in length from head to the tip of their tail when fully grown. Adult males weigh from 337 to 500 g while females weigh from 310 to 450 g. They are grey and brown in color with a long black stripe along the back of their coat. Their underbelly is creamy mahogany in color, which gives them their name. Mahogany gliders have a thin fold of skin between their front and rear legs that stretches out like a parachute when they leap, allowing them to glide distances of 30 to 60 m. Their long tail is used to stabilize them as they glide. ("ARKive", 2010; Jackson, 2000a)

Though solitary, mahogany gliders appear to be a socially monogamous. Their breeding season extends from April through October, but little else is known about the mating systems of this species. (Jackson, 2000b)

Mahogany gliders breed between April and October. They usually breed once a year, producing litters of 1 to 2 offspring. Occasionally, females breed twice in one season when the first litter is born early enough in the season to permit a second attempt at breeding. They may also breed twice in a season if the first litter of offspring dies. Weaning occurs between 4 and 5 months of age. Once weaned, juveniles disperse from the nest to survive on their own; this generally occurs within their first year. Mahogany gliders reach sexual maturity at 12 to 18 months of age. It has been suggested that the breeding rate of females does not fully peak until their second year when they reach full adult size and weight. ("Mahogany Glider", 2010; Jackson, 2000a; Jackson, 2001)

Female mahogany gliders are the primary caregiver to offspring, carrying them in their pouch until they are weaned at 4 to 5 months of age. Females have been observed raising young in up to 12 different nests per season. Little is known about post-weaning habits of offspring. Although mahogany gliders appear to be monogamous, there is no evidence supporting male investment in care of offspring. (Jackson, 2000a; Jackson, 2001)

Little is known regarding the lifespan of mahogany gliders, as the longest studies focusing on this species have been no more than 2 years in duration. However, it is thought that the lifespan of mahogany gliders is similar to that of the sugar glider of Australia, which is aproximately 6 years. (Jackson, 2000a)

Mahogany gliders tend to be a solitary, though they do appear to be socially monogamous. Males and females do not forage with one another, and they generally sleep in separate dens. This suggests efficiency in defending their home-range from other conspecifics as well as increased exploratory capabilities. They have upwards of 10 dens per season. Dens are usually made in hollows in Eucalyptus and bloodwood trees and are lined with a thick mat of leaves. Almost totally silent, this species rarely vocalizes more than once a night, emitting a nasal sounding "na-when" call. This vocalization lasts no more than 10 minutes, and responses from either sex are rare. Mahogany gliders can glide distances of 30 to 60 m. ("ARKive", 2010; "Mahogany Glider", 2010; Jackson, 2000b)

Mahogany gliders are very defensive of their territory, viciously attacking other mahogany gliders that trespass within it. The territory size of mahogany gliders is about 20 ha for males and 10 ha for females. Individuals of both sexes travel the border of their territory in a "foraging loop" every 2 to 3 nights either early in the evening before feeding or after feeding prior to returning to their den. This loop appears to have two purposes: to maintain defensive borders as well as to locate trees that may be fruiting or flowering in the near future. Well developed scent glands on the front of their heads as well as on the front of the chest of males help to maintain the home range of mahogany gliders. Scent marking is also performed by urinating on the branches of trees. ("Mahogany Glider", 2010; Jackson, 2000b)

Mahogany gliders are solitary and monogamous, and the only vocal communication seems to be aimed at an individual of the opposite sex in the form of a nasal sounding "na-when" cry. This is rarely returned by the other glider. Even when defending their territory, mahogany gliders are virtually silent. Most communication is carried out through scent marking. Mahogany gliders have scent glands in the front part of their head, and in males on the front of their chest, which they rub on trees in their territory. They also urinate on tree branches to mark territory. (Jackson, 2000b)

Mahogany gliders are nectivorous and folivorous. They primarily feed on nectar and pollen from a variety of trees and shrubs within their home-range, including many species from the family Myrtaceae such as Corymbia (Corymbia intermedia), Eucalyptus (Eucalyptus cloeziana) and Melaleuca (Melaleuca dealbata). At higher elevations, Bankasia trees such as Bankasia aquilonia and Bankasia plagiocarpa are also likely sources of food. When little else is flowering, mahogany gliders also consume Acacia trees, including Acacia crassicarpa, A. flavescars and A. mangium. They also eat some insects. (Jackson, 2000b; Jackson, 2001)

Most plants in the diet of mahogany gliders are available during certain times of the year. Timing and availability of food affects time and energy invested in foraging, including the distance traveled to obtain food. During times of a high flowering index, mahogany gliders tend to travel further and maintain a larger home-range. During times of a low flowering index, they appear to maintain a smaller home range. (Jackson, 2000b; Jackson, 2001)

A variety of organisms prey on mahogany gliders, including Amethystine pythons, Rufus owls, Barking owls, Masked owls, Sooty owls, and Carpet pythons. ("Mahogany Glider", 2010)

Mahogany gliders are mutualists with many species of trees including those in the families Myrtaceae and Xanthorrhoea. While feeding on pollen and nectar, pollen gets caught in their fur and is dispersed as they continue to forage. ("Mahogany Glider", 2010; Dettmann, et al., 1995; Jackson, 2001)

There are no known direct positive effects of mahogany gliders on humans. Because they are important pollinators, however, they help maintain a thriving ecosystem in the forests of Australia.

As endangered species, mahogany gliders may induce economic cost to the Australian government, which is attempting to create a conservation area for this species. This could limit building sites and roads in certain areas and could also limit areas to be used for agriculture. Otherwise, there are no known adverse effects of mahogany gliders on humans. ("ARKive", 2010; Wildlife, 2010)

Mahogany gliders are listed as endangered by the IUCN and are listed on the Australian Endangered Species Protection Act of 1992. Less than 20 % of their habitat remains because of clearing for agriculture, intensive grazing, weed invasion, forestry, and human settlement. Their population is currently estimated to be 1,500 individuals and is declining. Because mahogany gliders require near continuos vegetation, roads, power lines, and railway lines prevent movement to potential habitats. A recovery plan was created in 1999, recommending action to maintain populations of mahogany gliders, and both government and community are starting to respond. National refuges and national parks are becoming important habitat for this species. Barbed wire fences which cause death in this species are slowly being altered. Additionally, artificial den boxes have been created in some areas of fragmented habitat, which are used by mahogany gliders. ("ARKive", 2010; "Mahogany Glider", 2010)

Although first described in 1883, Mahogany gliders were thought to be a subspecies of the more common squirrel glider (Petaurus norfolcensis) for over 100 years. They were "rediscovered" in 1989 and attained the status of species in 1993. ("ARKive", 2010)