Petaurussquirrel gliders, sugar gliders, and yellow bellied gliders

Diversity

The genus Petaurus, also known as the lesser gliding possums, are known for their ability to glide between trees. Their patagium (gliding membrane) connects from their front feet to their back ankles and they change their direction and speed as they drift from tree limb to tree limb. They also have opposable thumbs to assist in climbing those trees and eating. Recently, they have been reclassified into eight distinct species. (Cremona, et al., 2021; Nowak, 1999)

Geographic Range

The different species of Petaurus reside in Australia, New Guinea, and other surrounding islands. There is much overlap in the species’ range, which for a long time resulted in incorrect classifications. The eastern coast of Australia is home to Petaurus norfolcensis, Petaurus gracilis, Petaurus australis, Petaurus notatus, and Petaurus breviceps. Petaurus abidi resides mainly on the island of New Guinea and Petaurus ariel resides mainly in the northwestern coastal region of Australia. In addition, Petaurus biacensis predominantly inhabits the Biak Island, just north of New Guinea. They tend to remain near coasts, where there is more vegetation, and likely all originated in Australia before colonizing the nearby islands. (Banks, 2017; Cremona, et al., 2021; Jackson and Thorington Jr, 2012; Nowak, 1999; Sharpe and Goldingay, 2007)

Habitat

These animals evolved in an area where incomplete canopies were dominant, so their gliding membranes helped them get from tree to tree. Since they are great climbers, most of their time is spent up in the canopy of the eucalyptus trees, away from predators and then only glide down when they have a reason to. Their omnivorous diet works well with this habitat since they get most of their nutrition from nectar, sap, and insects which are found in the trees. (Banks, 2017; Cremona, et al., 2021; Jackson and Thorington Jr, 2012; Nowak, 1999; Sharpe and Goldingay, 2007)

Systematic and Taxonomic History

Within Metatheria, this genus is a part of the clade Diprotodontia which consists of the "classic" marsupials like kangaroos, koalas, and wallabies. They are further classified as a part of the family Petauridae, containing the arboreal possums of Australia. The subfamily Petaurinae originally included genus Petaurus with genus Gymnobelideus. Later research concluded that genus Gymnobelideus was more closely related to genera in other subfamilies. Members of Petaurinae have many common features such as three single-cusped upper pre-molars and slightly curved procumbent lower incisors. Although in separate sub families, Petaurus' closest relatives are other members of Petauridae like Gymnobelideus leadbeateri, and members of genus Dactylopsila. (Nowak, 1999; "One Zoom: All life", 2021)

  • Synonyms
    • Sometimes referred to as the lesser gliding possums
  • Synapomorphies
    • Gliding membrane between front and hind limbs
    • Entirely furred semiprehensile tails
    • Well developed pouch in females.

Physical Description

The genus Petaurus is most known for their gliding membrane that stretches from the front to hind limbs but many features can distinguish them from other gliding organisms. Their heads and bodies measure around 120-320mm with their tail measuring 150-480mm. The range is deu to differing species being of mildly differing sizes, the biggest, P. australis weighing in at 435-710 grams, and the smallest, P. breviceps weighing in at just 79-160 grams. Skull size has also been used to classify different species and was recently used to support the splitting of P. breviceps into four distinct species. In addition, their tails are semi-prehensile and fully-furred, separating Petaurus from many related groups. All species of this genus have countershading, mostly grey on their dorsal side and lighter coloring on their ventral side. P. australis differs in that it is browner in color on the dorsal side, and an orange-yellow color on their ventral side, giving them the nickname, the yellow-bellied gliders. Similar to some other species in their family, they have a dark dorsal stripe that extends from their nose to the base of their tails. This stripe varies in thickness across the body and can vary from individual to individual. They have dark pelage around their eyes and ears that generally connects around the nose. This darker pelage can also be found on the dorsal side of their forelimbs and occasionally on the hindlimbs. Additionally, there are few significant differences in the morphology of each sex, but in males, bare patches can be found on the head and throat where secretions can more effectively be released. The pouches of all species are fully formed, but P. australis has a well-furred septum dividing its pouch into two compartments. Juveniles don't differ greatly from adults, their fur just being more downy and slightly longer than most adults. (Cremona, et al., 2021; McKay, 1989; Nowak, 1999)

  • Sexual Dimorphism
  • sexes alike

Reproduction

Nesting is in groups of up to seven males and females, then also their young with one or two dominant males doing most of mating. The dominant males are generally heavier, have higher testosterone, and lower cortisol. Mating is done in some monogamous pairs, but when food is abundant, polygynous units are popular. Breeding time is variable depending on species and range, some have specific cycles, while others breed year round when their circumstances allow. They have a 29 day estrous cycle, with generally only one to three young per female, depending on the species. If the first litter is lost or weaned, and if it is still during the breeding period and resources are abundant, the mother can have a second litter. ("Behavioral and endocrinological correlates of social status in the male sugar glider (Petaurus breviceps Marsupialia: Petauridae)", 1994; Brown, et al., 2007; Fokidis and Risch, 2008)

Since the dominant male does the majority of the mating, courting behaviors are not common. In monogamous pairs, males spend around half of their active time within 25m of their partner, and 55-85% of their sleeping time with their female partner. ("Behavioral and endocrinological correlates of social status in the male sugar glider (Petaurus breviceps Marsupialia: Petauridae)", 1994; Brown, et al., 2007; Fokidis and Risch, 2008)

Gestation ranges from two to three weeks, then it spends around 6 weeks attached to the nipple, emerges from pouch at around 10 weeks, leave the nest after another 6 weeks and is then relatively independent. They reach sexual maturity at about a year, a little less for females, a little more for males, and are producing young until around 8 years of age. Having a larger body mass contributes to higher reproduction rates but less flying efficiency so balancing these features is necessary in their reproductive physiology. They are K selected with low infant mortality, slow metabolism, and fewer offspring per litter. ("Behavioral and endocrinological correlates of social status in the male sugar glider (Petaurus breviceps Marsupialia: Petauridae)", 1994; Brown, et al., 2007; Fokidis and Risch, 2008)

  • Parental Investment
  • female parental care
  • pre-hatching/birth
    • provisioning
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • protecting
      • female
  • post-independence association with parents

Lifespan/Longevity

The lifespans of this genus in the wild has not been widely researched so information is quite sparse. In captivity they have been recorded to live as long as 17.8 years, but in the wild their longevity is strongly decreased, P. australis are known to have lived at least six years in the wild. Since P. breviceps has become a popular exotic pet, their captive lifespan is generally around 10-12 years, though they are considered geriatric around 5-7 years implying that may be close to their lifespan in the wild, before special care and medical interventions are needed. (Axelson, 2021)

Behavior

Petaurus species are nocturnal and rest in tree hollows in the day. In harsher times, they are able to achieve temporal heterothermy for up to 16 hours a day. Dominant males survey the area more, keep up territory protection and organize the rest of the group. (Goldingay, 1989; Nowack, et al., 2015)

Communication and Perception

The dominant male will scent the territory and the individuals in the group to communicate within the group and with surrounding groups and species. They also have a few unique calls, but this has not been recorded or researched much outside of P. australis. In that species, they have specific calls for different predators, and ones to define their territory to intruders. They have adequate vision, but not many specific adaptations for nocturnal living. (Goldingay, 1994)

Food Habits

Petaurus is generally omnivorous, feeding on various things in their environment. Since Eucalyptus of various species is available across the majority of their range, they will feed on its sap by tapping, or the honeydew formed by crystallized sap. They will also feed on nectar and pollens of various flowering plants and insects they find in tree bark. They are also known to occasionally feed on small birds and smaller mammals. The patagium is used to glide from tree to tree when foraging. It has been recorded that the mahogany glider, P. gracilis, spends approximately 44% of its time finding food. While being relatively small, they will aggressively protect a food source from larger animals hoping to get a meal, using claws, teeth, and anything else they can. (Jackson and Johnson, 2006; Smith, 1973)

Predation

Species within this genus have very complex calling and chemical communication systems. They have specific alarm calls and maintain a home range with their community to keep in contact with each other for protection. In their region, the main predators are feral dogs and cats, owls, foxes, quolls, and a few larger reptiles such as goannas and pythons. (Smith, 1973)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

These animals play an often-underrated role in their ecosystems, leaving much to still be discovered about their impacts. They aid in the spreading of pollen and seeds because of their diet, providing a necessary boost to the native Australian vegetation. They generally nest in the hollows of trees if available, creating a bed of leaves, which can then be reused by other animals if abandoned. (Jackson and Johnson, 2006; McKay, 1982; Smith, 1973; Welsh, et al., 1910)

  • Ecosystem Impact
  • disperses seeds
  • pollinates
Commensal/Parasitic Species

Economic Importance for Humans: Positive

P. breviceps is a common exotic pet that has grown in popularity over the past few years. While this species in the pet trade is highly debated, and in some areas, illegal to own or distribute, it is often kept as a unique gliding friend. (Axelson, 2021)

Economic Importance for Humans: Negative

There are no known adverse effects of Petaurus on humans.

Conservation Status

While there is not extensive research on the conservation status of Petaurus, the IUCN has information on a few of the species. For P. breviceps, as the most researched of this genus, are least concern and stable. P. australis, P. abidi, P. norfolcensis, and P. gracilis are all decreasing in population, but are at varying levels of concern. P. australis is considered near threatened, P. abidi critically endangered, P. norfolcensis least concern, and P. gracilis endangered. The final species that IUCN has information on is P. biacensis who are considered least concern with unknown population trends as of 2015. This information is somewhat outdated with the amount of environmental change that has occurred to their habitat and around the world. With that being said, the information gives a starting place to infer what might be happening with this genus right now. Since the main concerns for this species involve habitat destruction due to logging industries and urban sprawl, it can be assumed that these problems are still causes for concerns in this genus and are likely still contributing to the current decline. Some action is being taken legally and socially to improve the care for the environment, like replanting forests and labeling protected areas. (Banks, 2017; "IUCN Redlist: Petaurus", 2021)

  • IUCN Red List [Link]
    Not Evaluated

Contributors

Audrey Bowman (author), Colorado State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

acoustic

uses sound to communicate

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

omnivore

an animal that mainly eats all kinds of things, including plants and animals

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

polygynous

having more than one female as a mate at one time

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

1994. Behavioral and endocrinological correlates of social status in the male sugar glider (Petaurus breviceps Marsupialia: Petauridae). Physiology and Behavior, 55 (6): 1131-1134.

2021. "IUCN Redlist: Petaurus" (On-line). IUCN Redlist. Accessed November 29, 2021 at https://www.iucnredlist.org/search?taxonomies=105642&searchType=species.

2021. "One Zoom: All life" (On-line). Accessed September 21, 2021 at https://www.onezoom.org/life.html.

Axelson, R. 2021. "Sugar Gliders - Owning" (On-line). VCA Hospitals. Accessed September 29, 2021 at https://vcahospitals.com/know-your-pet/sugar-gliders-owning.

Banks, S. 2017. Conserving and restoring endangered southern populations of the Squirrel Glider (Petaurus norfolcensis) in agricultural landscapes. Ecological Management & Restoration, 18(1): 15-25. Accessed September 12, 2021 at https://doi.org/10.1111/emr.12245.

Bell, S., C. McAlpine. 2010. Influence of contrasting urban edges on the abundance of arboreal mammals: A study of squirrel gliders ( Petaurus norfolcensis) in southeast Queensland, Australia. Biological Conservation, 143(1): 60-71. Accessed September 12, 2021 at https://doi.org/10.1016/j.biocon.2009.09.003.

Brown, M., S. Carthew, S. Cooper. 2007. Monogamy in an Australian arboreal marsupial, the yellow-bellied glider (Petaurus australis). Australian Journal of Zoology, 55 (3): 185-195.

Cremona, T., A. Baker, S. Cooper, R. Montague-Drake, A. Stobo-Wilson, S. Carthew. 2021. Integrative taxonomic investigation of Petaurus breviceps (Marsupialia: Petauridae) reveals three distinct species. Zoological Journal of the Linnean Society, 191(2): 503-527.

Fokidis, B., T. Risch. 2008. The Burden Of Motherhood: Gliding Locomotion In Mammals Influences Maternal Reproductive Investment. Journal of Mammalogy, 89. Issue 3: 617-625.

Goldingay, R. 1994. Loud Calls of the Yellow-Bellied Glider, Petaurus-Australis - Territorial Behavior by an Arboreal Marsupial. Australian Journal of Zoology, 42(3): 279-293.

Goldingay, R., S. Jackson. 2004. The biology of Australian possums and gliders. Chipping Norton, New South Wales: Surey Beatty and Sons.

Goldingay, R. 1989. The behavioural ecology of the gliding marsupial, Petaurus australis. Wollongon, Australia: University of Wollongong.

Jackson, S. 2001. Foraging behaviour and food availability of the mahogany glider Petaurus gracilis (Petauridae: Marsupialia). Journal of Zoology, 253(1): 1-13.

Jackson, S., R. Thorington Jr. 2012. Gliding mammals: taxonomy of living and extinct species. Washington D.C: Smithsonian Institution Scholarly Press.

Jackson, S., C. Johnson. 2006. Jackson, S. M., and Jackson, C.N. (2002). Time allocation to foraging in the mahogany glider Petaurus gracilis (Marsupialia, Petauridae) and a comparison of activity times in exudivorous and folivorous possums and gliders.. Journal of Zoology, 256(2): 271-277.

Lindenmayer, D. 2002. Gliders Of Australia: A Natural History. Sydney, New South Wales: UNSW Press.

Malekian, M., S. Cooper, J. Norman, L. Christidis, S. Carthew. 2010. Molecular systematics and evolutionary origins of the genus Petaurus (Marsupialia: Petauridae) in Australia and New Guinea. Molecular Phylogenetics and Evolution, 54(1): 122-135.

McKay, G. 1989. Family Petauridae. Pp. 1-29 in B Richardson, D Walton, eds. Fauna of Australia, Vol. 1B. Australia: AGPS Canberra. Accessed September 17, 2021 at https://www.environment.gov.au/science/abrs/publications/fauna-of-australia/fauna-1b.

McKay, G. 1982. Nomenclature of the gliding possum genera Petaurus and Petauroides (Marsupialia: Petauridae). Australian Mammalogy, 5: 37-39.

Murray, J., S. Donnellan, G. McKay, R. Rofe, P. Baverstock, D. Hayman, M. Gelder. 1990. The Chromosomes of 4 Genera of Possums From the Family Petauridae (Marsupialia, Diprotodonta). Australian journal of zoology, 38(1): 33-39.

Nowack, J., A. Rojas, G. Kortner, F. Geiser. 2015. Snoozing through the storm: Torpor use during a natural disaster. Scientific Reports, 5(1): 1-6.

Nowak, R. 1999. Walker's Mammals of the World: Volume 1. Baltimore, Maryland: John's Hopkins University Press.

Sharpe, D., R. Goldingay. 2007. Home Range of the Australian Squirrel Glider, Petaurus norfolcensis (Diprotodontia). Journal of Mammalogy, 88(6): 1515-1522.

Smith, M. 1973. Petaurus hreviceps. MAMMALIAN SPECIES, No. 30: 1-5.

Welsh, D., J. Barling, E. Dalyell, M. Burfitt. 1910. Haemogregarina Petauri: A Haemogregarine of a Marsupial Flying Squirrel. Sydney, New South Wales: The Pathological Laboratories, University of Sydney.