Sugar gliderDescription

The sugar glider (Petaurus breviceps) is a small, omnivorous, arboreal, and nocturnal gliding possum belonging to themarsupial infraclass. The common name refers to its preference for sugary nectarous foods and ability to glide through the air, much like a flying squirrel.[5] They have very similar appearance and habits to the flying squirrel despite not being closely related (an example of convergent evolution).[6] The scientific name, Petaurus breviceps, translates from Latin as “short-headed rope-dancer”, a reference to their canopy acrobatics.[7]

Sugar gliders are characterised by their gliding membrane, known as the patagium, which extends from their forelegs to hindlegs.[8] Gliding serves as an efficient means of both locating food and evading predators.[5] They are covered in soft, pale grey to brown fur, which is lighter in colour on their underside. The sugar glider is endemic to mainland Australia, Indonesia, and New Guinea and its surrounding islands; and was probably introduced to Tasmania in the 1830s.[9][10][11]

The sugar glider has a squirrel-like body with a long, partially (weakly)[20] prehensile tail. The length from the nose to the tip of the tail is about 24 to 30 cm (12–13 inches), and males and females weigh 140 grams and 115 grams respectively.[21] Heart rate range is 200-300 beats per minutes, and respiration rate is 16-40 breaths per minute.[22] The sugar glider is a sexually dimorphic species, with males typically larger than females. Sexual dimorphism has likely evolved due to increased mate competition arising through social group structure; and is more pronounced in regions of higher latitude, where mate competition is greater due to increased food availability.[23]

The sugar glider has a thick, soft fur coat that is usually blue-grey; although some have been known to be yellow, tan or (rarely) albino[a] A black stripe is seen from its nose to midway on its back. Its belly, throat, and chest are cream in colour. Males have four scent glands, located on the forehead, chest, and two paracloacal (associated with, but not part of the cloaca which is the common opening for the intestinal, urinal and genital tracts) that are used for marking of group members and territory.[9] Scent glands on the head and chest of males appear as bald spots. Females also have a paracloacal scent gland, as well as a scent gland in the pouch, but do not have scent glands on the chest or forehead.[9] It is nocturnal, and its large eyes help it to see at night, and its ears swivel to help locate prey in the dark. The eyes of the sugar glider are set far apart, allowing them to triangulate the distance between launch and landing location during gliding.[24] The sugar glider has five digits on each foot, with an opposable toe on each hind foot. These opposable toes are clawless, and bend in a way that they can touch all the other digits, like a human thumb, allowing the sugar glider to firmly grasp branches. The second and third digits of the hind foot are partially syndactylous (fused together), forming a grooming comb.[20] The fourth digit of the fore foot is sharp and elongated, aiding in extraction of insects under the bark of trees.[9] The gliding membrane extends from the outside of the fifth digit of each forefoot to the first digit of each hindfoot. When the legs are stretched out, this membrane allows the sugar glider to glide a considerable distance. The membrane is supported by well developed tibiocarpalis, humerodorsalis and tibioabdominalis muscles, and its movement is controlled by these supporting muscles in conjunction with trunk, limb and tail movement.[8]

Lifespan in the wild is up to 9 years; is typically up to 12 years in captivity,[7] and the maximum reported lifespan is 17.8 years.[25]

Distribution and habitat

Sugar gliders are found throughout the northern and eastern parts of mainland Australia, Tasmania, New Guinea and several associated isles, the Bismarck Archipelago, Louisiade Archipelago, and certain isles of Indonesia, Halmahera Islands of theNorth Moluccas.[14] The earliest Australian sugar glider Sugar Glider mapfossils were found in a cave in Victoria and are dated to 15 000 years ago, at the time of the Pleistocene epoch.[9] The facilitated introduction of the sugar glider to Tasmania in 1835[15] is supported by the absence of skeletal remains in subfossil bone deposits and the lack of an Aboriginal Tasmanian name for the animal.[5] In Australia, sugar glider distribution corresponds with forests along the southern, eastern and northern coastlines, and extends to altitudes of 2000 m in the eastern ranges.[9] Sugar gliders occur in sympatry with the squirrel glider, mahogany glider, and yellow-bellied glider; and their coexistence is permitted through niche partitioning where each species has different patterns of resource use.[16]

They have a broad habitat niche, inhabiting rainforests and coconut plantations in New Guinea; and rainforests, wet or dry sclerophyll forest and acacia scrub in Australia; preferring habitats with Eucalpyt and Acacia species.[17] The main structural habitat requirements are a large number of stems within the canopy, and dense mid and upper canopy cover, likely to enable efficient movement through the canopy.[16] Like all arboreal, nocturnal marsupials, sugar gliders are active at night, and shelter in tree hollows lined with leafy twigs during the day.[18] The average home range of sugar gliders is 0.5 hectares, and is largely related to the abundance of food sources;[19] density ranges from 2-6 individuals per hectare.

Native owls (Ninox sp.)[9] are their primary predators; others in their range include kookaburras, goannas, snakes, and quolls.[15] Feral cats (Felis catus) also represent a significant threat.