Rock-haunting Ringtail Possum
Encyclopedia
The Rock-haunting Ringtail Possum (Petropseudes dahli), also known as the Rock Ringtail Possum, is a species of Australia
n possum
. It is found in rocky escarpments in the Kimberley
, Arnhem Land
and Gulf of Carpentaria
across Western Australia
and Northern Territory
and just passing the Queensland
border. It is also found on Groote Eylandt
. It the only species in the genus Petropseudes, but is part of the group including the Common Ringtail Possum
(Pseudocheirus peregrinus).
The Rock-haunting Ringtail Possum has one of the shortest tails of all ringtail possums, and at its end it is hairless and scaly. It lives in small groups and is mainly herbivorous. It has a stocky build and is mostly grey in colour.
. It is grey to reddish-grey in color on the back, while its underside is a light cream color. It has white hair patches underneath its small, round ears and both above and below the eyes. A mid-dorsal stripe runs from the crown of the head to the middle of the back. Just like other possums, it has a prehensile tail, adapted for grasping especially by wrapping around. However, the tail is unique in its appearance compared to that of other possums' as it is covered with fur only half way down. Males are 334 to 375 mm long while females are generally bigger and range from 349 to 383mm in length and they weigh between 1280 to 2000 grams. Another uncommon feature in the appearance of this species is that it has vertical pupils.
s, flower
s and leaves
of a variety of trees found near its habitat and occasionally feeds on termite
s. It usually stays close to the rocks while feeding but has been found as far as 100m from the nearest outcrop. Most common of the blossoms it eats are of Darwin Woollybutt (Eucalyptus miniata
) and Darwin Stringybark (Eucalyptus tetrodonta). Its major fruit intake is from Zyziphus oenoplia, Vitex glabrata, Billy Goat Plum (Terminalia ferdinandiana
), and Owenia vernicosa. Leaves eaten include Flagelleria indica, Pouteria sericea and Vine Reedcane.
(Canis lupus dingo), the Oenpelli Python (Morelia oenpelliensis), the Olive Python (Liasis olivaceous), quoll
s (Dasyurus spp.), owl
s (Strigiformes), feral cats (Felis catus), domestic dogs (Canis lupus familiaris) and human
s (Homo sapiens). The Rock-haunting Ringtail Possum spends a large amount of time participating in sentinel behavior to avoid predators. It perches on branches or ledges and scans the area for danger. In an attempt to deter predators and to warn others, this possum beats its tail against tree branches vigorously causing the entire tree to shake.
, moving into the trees only to feed. This distinguishes it from its close, mostly arboreal relatives. Its eye-shine is very bright in a spotlight but unlike most possums, it doesn't freeze when caught in a bean of light. Instead, it retreats to its rock shelter or crevices where it hides with its head in the crevice but its body exposed.
period information is not available for the species, it is known that close relatives have gestation periods from 16 to 30 days. The new offspring spends its first five weeks in the female's large pouch which has two teats. The parents usually carry the new offspring on their back after they have left the mother's pouch. Caring for the young is divided nearly equally among the parents. The parents are assisted in raising the offspring by the previous offspring who commonly stay with the family unit. The parents practice protective behaviors such as spend time watching for predators, tail beating, and vocalizing and marshaling the young to keep them relatively close.
The Rock-haunting Ringtail Possum is one of few obligate monogamous marsupial species. A consistent characteristic of obligate monogamy displayed by this species is the existence of cohesive and persistent pair bonds with mutual or asymmetrical attraction between adults. Both sexes of this species maintain strong pair bonds, as shown by the wide array of maintenance behaviours, which is a measure of bond 'strength'. However, males maintained the pair bond at a higher rate than females. Both sexes shared the decision-making process in terms of changing group activity.
Presence of long-lasting bonds between parents and young seen in the family of this species is another attribute of obligate monogamy. Both sexes of the Rock-haunting Ringtail Possum showed substantial long-term care of offspring. An unusual interaction observed between parents and young were the embrace by adult males and the bridge formation. Both sexes embrace young, whereas only females engage in bridge formation. The mother allows her young to move from branch to branch by using her body as a bridge. This has never been seen in another possum. Embracing is a way for the adults to know the stage of maturation of the offspring. A third feature of obligate monogamy shown by the Rock-haunting Ringtail Possum is the rearing of younger siblings by juveniles.
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n possum
Possum
A possum is any of about 70 small to medium-sized arboreal marsupial species native to Australia, New Guinea, and Sulawesi .Possums are quadrupedal diprotodont marsupials with long tails...
. It is found in rocky escarpments in the Kimberley
Kimberley region of Western Australia
The Kimberley is one of the nine regions of Western Australia. It is located in the northern part of Western Australia, bordered on the west by the Indian Ocean, on the north by the Timor Sea, on the south by the Great Sandy and Tanami Deserts, and on the east by the Northern Territory.The region...
, Arnhem Land
Arnhem Land
The Arnhem Land Region is one of the five regions of the Northern Territory of Australia. It is located in the north-eastern corner of the territory and is around 500 km from the territory capital Darwin. The region has an area of 97,000 km² which also covers the area of Kakadu National...
and Gulf of Carpentaria
Gulf of Carpentaria
The Gulf of Carpentaria is a large, shallow sea enclosed on three sides by northern Australia and bounded on the north by the Arafura Sea...
across Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
and Northern Territory
Northern Territory
The Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...
and just passing the Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
border. It is also found on Groote Eylandt
Groote Eylandt
Groote Eylandt is the largest island in the Gulf of Carpentaria in northeastern Australia. It is the homeland of, and is owned by, the Anindilyakwa people who speak the isolated Anindilyakwa language)....
. It the only species in the genus Petropseudes, but is part of the group including the Common Ringtail Possum
Common Ringtail Possum
The common ringtail possum is an Australian marsupial. It lives in a variety of habitats and eats a variety of leaves of both native and introduced plants, as well as flowers and fruits. These dietary factors have, over time, aided burgeoning introduced populations in New Zealand...
(Pseudocheirus peregrinus).
The Rock-haunting Ringtail Possum has one of the shortest tails of all ringtail possums, and at its end it is hairless and scaly. It lives in small groups and is mainly herbivorous. It has a stocky build and is mostly grey in colour.
Description
The Rock-haunting Ringtail Possum is almost as big in size as a small rabbitRabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
. It is grey to reddish-grey in color on the back, while its underside is a light cream color. It has white hair patches underneath its small, round ears and both above and below the eyes. A mid-dorsal stripe runs from the crown of the head to the middle of the back. Just like other possums, it has a prehensile tail, adapted for grasping especially by wrapping around. However, the tail is unique in its appearance compared to that of other possums' as it is covered with fur only half way down. Males are 334 to 375 mm long while females are generally bigger and range from 349 to 383mm in length and they weigh between 1280 to 2000 grams. Another uncommon feature in the appearance of this species is that it has vertical pupils.
Ecology
The Rock-haunting Ringtail Possum disperses seeds through its fruit eating habits. It also influences termite populations and acts as prey for regional predators. The Rock-haunting Ringtail Possum has been affected by human induced habitat fragmentation and hence, its numbers have decreased significantly. The species is listed as a priority species in Western Australia.Habitat
The Rock-haunting Ringtail Possum lives exclusively in rocky outcrops and prefers areas with large boulders and deeply fissured rock. It uses the crevices to hide by just sticking its head into the crevice with the body exposed. It is strictly nocturnal; it only moves out of it sheltered rock crevices to climbing trees to feed at night. It does not make a nest and has been observed occasionally to be sleeping in well protected rock ledges during the day. This suggests a high level of adaptation to a terrestrial existence. Indicators of a reduction in arboreal adaptation are shorter legs, shorter claws, shorter tail and a slightly longer snout.Diet
The Rock-haunting Ringtail Possum eats fruitFruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
s, flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s and leaves
Leaves
-History:Vocalist Arnar Gudjonsson was formerly the guitarist with Mower, and he was joined by Hallur Hallsson , Arnar Ólafsson , Bjarni Grímsson , and Andri Ásgrímsson . Late in 2001 they played with Emiliana Torrini and drew early praise from the New York Times...
of a variety of trees found near its habitat and occasionally feeds on termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
s. It usually stays close to the rocks while feeding but has been found as far as 100m from the nearest outcrop. Most common of the blossoms it eats are of Darwin Woollybutt (Eucalyptus miniata
Eucalyptus miniata
The Darwin woollybutt is a eucalypt which is native to Australia's Top End, found from Cape York in north Queensland across through to the Northern Territory into the Kimberley Region of northern Western Australia. It is a medium-sized tree which can reach 15–25 m in height. The bark is soft and...
) and Darwin Stringybark (Eucalyptus tetrodonta). Its major fruit intake is from Zyziphus oenoplia, Vitex glabrata, Billy Goat Plum (Terminalia ferdinandiana
Terminalia ferdinandiana
Terminalia ferdinandiana, also called the gubinge, billygoat plum, Kakadu plum or murunga is a flowering plant in the family Combretaceae, native to Australia, widespread throughout the tropical woodlands from northwestern Australia to eastern Arnhem Land.Its vitamin C concentration may be as high...
), and Owenia vernicosa. Leaves eaten include Flagelleria indica, Pouteria sericea and Vine Reedcane.
Known predators
Some known predators of the Rock-haunting Ringtail Possum are the DingoDingo
The Australian Dingo or Warrigal is a free-roaming wild dog unique to the continent of Australia, mainly found in the outback. Its original ancestors are thought to have arrived with humans from southeast Asia thousands of years ago, when dogs were still relatively undomesticated and closer to...
(Canis lupus dingo), the Oenpelli Python (Morelia oenpelliensis), the Olive Python (Liasis olivaceous), quoll
Quoll
The quoll, or native cat, is a carnivorous marsupial native to mainland Australia, New Guinea and Tasmania. It is primarily nocturnal and spends most of the day in its den. There are six species of quoll; four are found in Australia and two in New Guinea...
s (Dasyurus spp.), owl
Owl
Owls are a group of birds that belong to the order Strigiformes, constituting 200 bird of prey species. Most are solitary and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish...
s (Strigiformes), feral cats (Felis catus), domestic dogs (Canis lupus familiaris) and human
Human
Humans are the only living species in the Homo genus...
s (Homo sapiens). The Rock-haunting Ringtail Possum spends a large amount of time participating in sentinel behavior to avoid predators. It perches on branches or ledges and scans the area for danger. In an attempt to deter predators and to warn others, this possum beats its tail against tree branches vigorously causing the entire tree to shake.
Lifestyle
Of all the Australian possums, the Rock-haunting Ringtail Possum lives in the most tightly knit family groups. Adults and their young will stay within 2-3 metres of each other throughout the night. The family groups are generally made up of about 4 individuals, although group sizes of 2 to 10 individuals have been reported. The possum spends most of its time sheltered within rock piles or crevices. After dark it moves from its rocky home into the nearby trees where it feeds. This possum is secretive, difficult to trap and avoids contact and confrontation as far as possible. It is primarily terrestrialTerrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
, moving into the trees only to feed. This distinguishes it from its close, mostly arboreal relatives. Its eye-shine is very bright in a spotlight but unlike most possums, it doesn't freeze when caught in a bean of light. Instead, it retreats to its rock shelter or crevices where it hides with its head in the crevice but its body exposed.
Reproduction
There appears to be no particular season for breeding. However, females with a large young in the pouch and a young on the back have been seen in March, July, August and September. Although the gestationGestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
period information is not available for the species, it is known that close relatives have gestation periods from 16 to 30 days. The new offspring spends its first five weeks in the female's large pouch which has two teats. The parents usually carry the new offspring on their back after they have left the mother's pouch. Caring for the young is divided nearly equally among the parents. The parents are assisted in raising the offspring by the previous offspring who commonly stay with the family unit. The parents practice protective behaviors such as spend time watching for predators, tail beating, and vocalizing and marshaling the young to keep them relatively close.
Home range and obligate monogamy
Both sexes have about the same home range size. Average home range is 0.9 hectares, with home ranges ranging in size from 0.5 to 1.2 hectares. The average density in these home ranges is 0.4 possums per hectare. Females live with one male in their home range, which are commonly marked by scent posts. To scent-mark, the Rock-haunting Ringtail Possum rubs or presses their cloacal-caudal region or chest against the surface. While the possum also marked rock ledges and trees within its home ranges, scent marking was most vigorous around den sites.The Rock-haunting Ringtail Possum is one of few obligate monogamous marsupial species. A consistent characteristic of obligate monogamy displayed by this species is the existence of cohesive and persistent pair bonds with mutual or asymmetrical attraction between adults. Both sexes of this species maintain strong pair bonds, as shown by the wide array of maintenance behaviours, which is a measure of bond 'strength'. However, males maintained the pair bond at a higher rate than females. Both sexes shared the decision-making process in terms of changing group activity.
Presence of long-lasting bonds between parents and young seen in the family of this species is another attribute of obligate monogamy. Both sexes of the Rock-haunting Ringtail Possum showed substantial long-term care of offspring. An unusual interaction observed between parents and young were the embrace by adult males and the bridge formation. Both sexes embrace young, whereas only females engage in bridge formation. The mother allows her young to move from branch to branch by using her body as a bridge. This has never been seen in another possum. Embracing is a way for the adults to know the stage of maturation of the offspring. A third feature of obligate monogamy shown by the Rock-haunting Ringtail Possum is the rearing of younger siblings by juveniles.