The greater gliders are three species of large gliding
marsupials
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a po ...
in the genus ''Petauroides'', all of which are found in eastern
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
. Until 2020 they were considered to be one species, ''
Petauroides volans''. In 2020 morphological and genetic differences, obtained using
diversity arrays technology, showed there were three species subsumed under this one name. The two new species were named ''
Petauroides armillatus'' and ''
Petauroides minor
The northern greater glider (''Petauroides minor'') is a species of gliding marsupial endemic to the forests of north-central Queensland, Australia.
Taxonomy
It was initially described as a subspecies of ''Petauroides volans'', which alongsid ...
''.
These species are not closely related to the ''
Petaurus'' group of gliding marsupials but instead to the
lemur-like ringtail possum
The lemuroid ringtail possum (''Hemibelideus lemuroides''), also known as the lemur-like ringtail possum or the brushy-tailed ringtail, is a truly singular member of the ringtail possum group. It was once thought that they were gliding possums ( ...
, ''Hemibelideus lemuroides'', with which it shares the subfamily
Hemibelideinae
Pseudocheiridae is a family of arboreal marsupials containing 17 extant species of ringtailed possums and close relatives. They are found in forested areas and shrublands throughout Australia and New Guinea.
Characteristics
Physically, they ap ...
.
[
The greater gliders are ]nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
and are solitary herbivore
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...
s feeding almost exclusively on ''Eucalyptus
''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as euca ...
'' leaves and buds. Like their relative, the lemur-like ringtail, the southern greater glider is found in two forms: a sooty brown form and a grey-to-white form.[ The central greater glider is instead silvery brown, while the northern greater glider is brownish-gray.]
The greater gliders are found in eucalypt forests from Mossman, Queensland
Mossman is a rural town and locality in the Shire of Douglas, Queensland, Australia. It is the administrative centre for the Douglas Shire Council In the , the locality of Mossman had a population of 1,937 people.
Geography
Mossman in Far N ...
, to Daylesford, Victoria
Daylesford is a spa town located in the foothills of the Great Dividing Range, within the Shire of Hepburn, Victoria (Australia), Victoria, Australia, approximately 108 kilometres north-west of Melbourne. First established in 1852 as a gold-mini ...
.[
]
Taxonomy
Although the genus was formerly thought to be monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...
, there are now known to be three species in the genus:
* Central greater glider
The central greater glider (''Petauroides armillatus'') is a species of gliding marsupial native to the central coast of eastern Australia.
Taxonomy
It was initially described as a subspecies of ''Petauroides volans'', which alongside '' Pet ...
(''Petauroides armillatus'')
* Northern greater glider
The northern greater glider (''Petauroides minor'') is a species of gliding marsupial endemic to the forests of north-central Queensland, Australia.
Taxonomy
It was initially described as a subspecies of ''Petauroides volans'', which alongsid ...
(''Petauroides minor'')
* Southern greater glider
The southern greater glider (''Petauroides volans''), also known as the southern and central greater glider, is a species of large gliding marsupial native to the forests of southeastern Australia. It is a vulnerable species per the IUCN Red Li ...
(''Petauroides volans'')
The species are known to hybridize
Hybridization (or hybridisation) may refer to:
*Hybridization (biology), the process of combining different varieties of organisms to create a hybrid
*Orbital hybridization, in chemistry, the mixing of atomic orbitals into new hybrid orbitals
*Nu ...
with one another near the edges of their ranges.
Anatomy and physiology
The three species differ in their size, with the northern greater glider only growing to the size of a small ringtail possum
Pseudocheiridae is a family of arboreal marsupials containing 17 extant species of ringtailed possums and close relatives. They are found in forested areas and shrublands throughout Australia and New Guinea.
Characteristics
Physically, they ap ...
, while the southern greater glider grows to the size of a house cat
The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members o ...
. The central greater glider is intermediate between these two.
Greater gliders have a head and body long, with the females generally being larger than the males. Their body is covered with a shaggy coat of fur that increases their apparent size, and the tail is long and bushy, ranging from . The head is short with a pointed muzzle and their large ears are fringed and backed with long fur.
Each side of the body bears membranes
A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. Bi ...
stretching between the elbow and the ankle that give these animals the ability to perform controlled glide
Glide may refer to:
* Gliding flight, to fly without thrust
Computing
*Glide API, a 3D graphics interface
*Glide OS, a web desktop
*Glide (software), an instant video messenger
*Glide, a molecular docking software by Schrödinger (company), Schrà ...
s. This is in contrast to other gliding marsupials, such as the sugar glider
The sugar glider (''Petaurus breviceps'') is a small, omnivorous, arboreal, and nocturnal gliding possum belonging to the marsupial infraclass. The common name refers to its predilection for sugary foods such as sap and nectar and its ability ...
, that have gliding membranes stretching from the wrists to the ankles.
The feet have strongly recurved claws to grip onto bark or other surfaces. There are five toes on each foot. The first toe on the hind foot and the first two toes on the fore foot are opposable.[
The fur is soft and up to long. All three species have cream undersides and primarily differ in the coloration of their pelages. The ]northern greater glider
The northern greater glider (''Petauroides minor'') is a species of gliding marsupial endemic to the forests of north-central Queensland, Australia.
Taxonomy
It was initially described as a subspecies of ''Petauroides volans'', which alongsid ...
has a brownish-gray coloration, the central greater glider
The central greater glider (''Petauroides armillatus'') is a species of gliding marsupial native to the central coast of eastern Australia.
Taxonomy
It was initially described as a subspecies of ''Petauroides volans'', which alongside '' Pet ...
has a dark silvery-brown coloration with dark brown face, legs, and tail, while the southern greater glider
The southern greater glider (''Petauroides volans''), also known as the southern and central greater glider, is a species of large gliding marsupial native to the forests of southeastern Australia. It is a vulnerable species per the IUCN Red Li ...
varies between a dark, almost black morph or a pale white and gray morph. Body mass varies from in the southern greater glider of Victoria
Victoria most commonly refers to:
* Victoria (Australia), a state of the Commonwealth of Australia
* Victoria, British Columbia, provincial capital of British Columbia, Canada
* Victoria (mythology), Roman goddess of Victory
* Victoria, Seychelle ...
to in the northern greater glider of north Queensland
)
, nickname = Sunshine State
, image_map = Queensland in Australia.svg
, map_caption = Location of Queensland in Australia
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, established_ ...
.
Physiology
Heat management in the greater gliders is performed by licking extremities and the ventral
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...
body surface, and direct evaporation
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. High concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when humidi ...
is the main method of cooling. They can also use their gliding membranes to reduce heat loss by increasing the layer of insulation at the skin surface. The gliders are not well equipped to handle high ambient temperatures as they inefficiently use water for evaporation via salivation
Saliva (commonly referred to as spit) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be e ...
despite arboreal
Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...
habitats often having limited water accessibility.
These gliders can digest low nutrient foliage
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...
. Specifically eucalypt
Eucalypt is a descriptive name for woody plants with capsule fruiting bodies belonging to seven closely related genera (of the tribe Eucalypteae) found across Australasia:
''Eucalyptus'', '' Corymbia'', '' Angophora'', ''Stockwellia'', ''Allosyn ...
leaf matter, which contains a variety of phenolic
Phenolic is an adjective and a substantive (noun) that may apply to :
* Phenol (or carbolic acid), a colorless crystalline solid and aromatic compound
* Phenols, a class of chemical compounds that include phenol
* Phenolic content in wine
* Phenol ...
and terpenoid
The terpenoids, also known as isoprenoids, are a class of naturally occurring organic chemicals derived from the 5-carbon compound isoprene and its derivatives called terpenes, diterpenes, etc. While sometimes used interchangeably with "terpenes" ...
compounds and a high concentration of lignified fibre. These animals can digest about 50–60% of the leaf during its passage through the gut. Their guts have a specialized caecum
The cecum or caecum is a pouch within the peritoneum that is considered to be the beginning of the large intestine. It is typically located on the right side of the body (the same side of the body as the appendix, to which it is joined). The wo ...
that contains a population of bacteria that ferment food residues that remain undigested in the small intestine. For a population in a eucalypt
Eucalypt is a descriptive name for woody plants with capsule fruiting bodies belonging to seven closely related genera (of the tribe Eucalypteae) found across Australasia:
''Eucalyptus'', '' Corymbia'', '' Angophora'', ''Stockwellia'', ''Allosyn ...
forest near Maryborough, Queensland
Maryborough ( ) is a city and a suburb in the Fraser Coast Region, Queensland, Australia. At the 2021 Census, Maryborough had a population of 15,287.
Geography
Maryborough is located on the Mary River in Queensland, Australia, approximate ...
, it has been calculated that their daily energy intake is about 1130 kJ, which is provided by about of dry matter daily.
Mature females will give birth to a single joey each year which is typically born in late autumn or early winter. The underdeveloped offspring will then spend the next four months within the pouch of the mother to suckle and develop, and will remain within the security of the pouch until nine months of age.
Distribution and habitat
Greater gliders are found in southern Queensland
)
, nickname = Sunshine State
, image_map = Queensland in Australia.svg
, map_caption = Location of Queensland in Australia
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, established_ ...
, eastern Australia, southeastern New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
, and the montane forests of the Victoria
Victoria most commonly refers to:
* Victoria (Australia), a state of the Commonwealth of Australia
* Victoria, British Columbia, provincial capital of British Columbia, Canada
* Victoria (mythology), Roman goddess of Victory
* Victoria, Seychelle ...
n central highlands. It is usually tracked via spotlighting on transects (considered to underestimate the actual population size), radio tagging and owl-call playback.
The greater gliders choose habitat based on several factors, the dominant factor being the presence of specific species of eucalypt. Distribution levels are higher in regions of montane forest containing manna gum ('' E. viminalis'') and mountain gum ('' E. dalrympleana'', '' E. obliqua''). Furthermore, the presence of '' E. cypellocarpa'' appears to improve the quality of habitat for the greater gliders in forests dominated by ''E. obliqua''. Another factor determining population density is elevation. Optimal levels are 845 m above sea level. Within a forest of suitable habitat, they prefer overstorey basal areas in old-growth tree stands.
Behaviour
The greater gliders are primarily nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
, spending the night foraging
Foraging is searching for wild food resources. It affects an animal's Fitness (biology), fitness because it plays an important role in an animal's ability to survive and reproduce. Optimal foraging theory, Foraging theory is a branch of behaviora ...
in the highest parts of the forest canopy. During the day, they spend most of their time denning in hollowed trees, with each animal inhabiting up to twenty different dens within its home range. The dens are often lined with leaves and strips of bark. This is why spotlighting
Spotlighting or lamping (also known as jacklighting, shining, illuminating, and pit-lamping) is a method of hunting nocturnal animals using off-road vehicles and high-powered lights, spotlights, lamps or flashlights, that makes special use of ...
has become a popular way of locating members of a population. When a strong light is directed at the eyes of a glider, the observer will see two bright red orbs reflecting back.
Within forests, males and females will have home territories and set borders between other individuals. For males, home territory ranges from while that of females is only . Although home ranges may overlap, the animals remain generally solitary outside of the breeding season, and only rarely interact. In large and small patches of forest, the home territories will respectively be larger and smaller.
The gliding posture of the greater gliders is unique among marsupials. The forelimbs are folded so that the wrists are tucked under the chin, giving the patagium a triangular outline when outstretched. These animals regularly glide between high trees, and are able to use their tails to assist in steering. They avoid traveling along the ground whenever possible, and are slow and clumsy if forced to do so.[
Greater gliders do not make any loud sounds,] and are thought to communicate through scent marking. The animal's cloaca
In animal anatomy, a cloaca ( ), plural cloacae ( or ), is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles and birds, a ...
l glands give it a generally musty smell.[
]
Ecology
Greater gliders subsist almost entirely on the young leaves and flower bud
In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of a stem. Once formed, a bud may remain for some time in a dormant condition, or it may form a shoot immediately. Buds may be spec ...
s of select eucalypt species, especially ''Eucalyptus radiata
''Eucalyptus radiata'', commonly known as the narrow-leaved peppermint or Forth River peppermint, is a species of tree that is endemic to south-eastern Australia. It has rough, fibrous to flaky bark on the trunk and larger branches, smooth grey b ...
'', ''Eucalyptus viminalis
''Eucalyptus viminalis'', commonly known as the manna gum, white gum or ribbon gum, is a species of small to very tall tree that is endemic to south-eastern Australia. It has smooth bark, sometimes with rough bark near the base, lance-shaped to c ...
'', and ''Eucalyptus acmenoides
''Eucalyptus acmenoides'', commonly known as white mahogany or barayly,Les Robinson - Field Guide to the Native Plants of Sydney, page 40 is a tree that is endemic to eastern Australia. It is a large tree with grey to reddish brown, stringy b ...
''. Young leaves are preferred because they have higher concentration of protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
, and lower concentration of lignocellulose
Lignocellulose refers to plant dry matter (biomass), so called lignocellulosic biomass. It is the most abundantly available raw material on the Earth for the production of biofuels. It is composed of two kinds of carbohydrate polymers, cellulose a ...
which provides no nutrition. Overall, eucalypt leaves are a poor source of nutrients.
Due to its nocturnal lifestyle, a natural predator of the gliders is the Powerful Owl
The powerful owl (''Ninox strenua''), a species of owl native to south-eastern and eastern Australia, is the largest owl on the continent. It is found in coastal areas and in the Great Dividing Range, rarely more than inland. The IUCNRed List ...
(''Ninox strenua''). It hunts by concentrating in pockets within their relatively large home range until populations of prey are depleted to a level that causes the owl to shift hunting grounds. Other predators include feral cats, introduced to Australia with the arrival of Europeans.
Reproduction
The breeding season for greater gliders is relatively brief, lasting from February to May, with births occurring between April and June. Females have a relatively well-developed pouch, opening towards the forward part of the animal, and containing two teat
A teat is the projection from the mammary glands of mammals from which milk flows or is ejected for the purpose of feeding young. In many mammals the teat projects from the udder. The number of teats varies by mammalian species and often corre ...
s.[ Only a single young is born each year.][
At birth, the young weighs only around , but it does not begin to leave the pouch for about four months, by which time it is already furred and well developed. After leaving the pouch, the mother may carry it about on her back until it is weaned at about seven months of age. The young are independent at nine months, and reach sexual maturity between 18 months and two years after birth.][
Greater gliders have been recorded living up to fifteen years.]
Evolution
Although previously thought to be related to the other gliding possums, the greater glider genus, ''Petauroides'', is now known to be most closely related to the ringtail possum
Pseudocheiridae is a family of arboreal marsupials containing 17 extant species of ringtailed possums and close relatives. They are found in forested areas and shrublands throughout Australia and New Guinea.
Characteristics
Physically, they ap ...
s, and especially to the lemur-like ringtail possum
The lemuroid ringtail possum (''Hemibelideus lemuroides''), also known as the lemur-like ringtail possum or the brushy-tailed ringtail, is a truly singular member of the ringtail possum group. It was once thought that they were gliding possums ( ...
, from which its ancestors diverged around 18 million years ago. In contrast, it diverged from the gliding possums much earlier, around 36 million years ago. Fossils of greater gliders are known from the late Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
onwards, and show that the animal was once more widespread and inhabited other areas including parts of South Australia
South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...
.[
]
Conservation Status
Greater gliders as a whole are listed as vulnerable nationally, in Queensland and Victoria, under the EPBC Act, the Queensland Nature Conservation Act and Victorian Advisory List of Threatened Vertebrate Fauna. Given the split into three species, and the uniquely threatened statue of the southern species, this may need revision.
References
Bibliography
* Cronin, Leonard — "''Key Guide to Australian Mammals''", published by Reed Books Pty. Ltd., Sydney, 1991
* van der Beld, John — "''Nature of Australia — A portrait of the island continent''", co-published by William Collins Pty. Ltd. and ABC Enterprises for the Australian Broadcasting Corporation, Sydney, 1988 (revised edition 1992),
* Russell, Rupert — "''Spotlight on Possums''", published by University of Queensland Press, St. Lucia, Queensland, 1980,
* Troughton, Ellis — "''Furred Animals of Australia''", published by Angus and Robertson (Publishers) Pty. Ltd., Sydney, in 1941 (revised edition 1973),
* Morcombe, Michael & Irene — "''Mammals of Australia''", published by Australian Universities Press Pty. Ltd., Sydney, 1974,
* Ride, W. D. L. — "''A Guide to the Native Mammals of Australia''", published by Oxford University Press, Melbourne, 1970,
* Serventy, Vincent — "''Wildlife of Australia''", published by Thomas Nelson (Australia) Ltd., Melbourne, 1968 (revised edition 1977),
* Serventy, Vincent (editor) — "''Australia's Wildlife Heritage''", published by Paul Hamlyn Pty. Ltd., Sydney, 1975
External links
WPSQ Wildlife page on Greater Glider (includes photo)
- Wildlife Preservation Society of Queensland
The Wildlife Preservation Society of Queensland (Wildlife Queensland) based in Queensland, Australia is a not-for-profit organisation which aims to engage communities to deliver conservation outcomes.
Founded in 1962, Wildlife Queensland works ...
{{Taxonbar, from=Q10804830
Gliding possums
Marsupial genera
Taxa named by Oldfield Thomas