The common ringtail possum (''Pseudocheirus peregrinus'',
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
for "false hand" and
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
for "pilgrim" or "alien") is an Australian
marsupial
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 ...
.
It lives in a variety of habitats and eats a variety of leaves of both native and introduced plants, as well as flowers, fruits and sap. This
possum also consumes a special type of faeces that is produced during the daytime when it is resting in a nest. This behaviour is called
caecotrophy and is similar to that seen in rabbits.
Taxonomy
The common ringtail possum is currently classified as the only living species in the genus ''
Pseudocheirus
''Pseudocheirus'' is a genus of ringtail possums (family Pseudocheiridae). It includes a single living species, the common ringtail possum (''Pseudocheirus peregrinus'') of Australia, as well as the fossil ''Pseudocheirus marshalli'' from the Pli ...
''; the species of ''
Pseudochirulus
Slender ringtail possum or Small ringtail possum (''Pseudochirulus''), also known as the ringtail possum, is a genus of marsupial in the family Pseudocheiridae native to Indonesia, Papua New Guinea and Queensland, Australia. ''Pseudochirulus'' l ...
'' and other ringtail genera were formerly also classified in ''Pseudocheirus''. Several subspecies have been described, such as the Western Australian ''
Pseudocheirus peregrinus occidentalis
The western ringtail possum or ngwayir refers to a species of possum, ''Pseudocheirus occidentalis'', found in a small area of Southwest Australia. They are a cat-sized marsupial with a stocky build, dark greyish-brown fur, pale underparts and ...
'', but the entire population may be a
species complex
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
.
The arrangement as the only extant species of ''Pseudocheirus'' is:
*''Pseudocheirus peregrinus pereginus'', the type subspecies based on a collection made at
Endeavour River
The Endeavour River ( Guugu Yimithirr: ''Wabalumbaal''), inclusive of the Endeavour River Right Branch, the Endeavour River South Branch, and the Endeavour River North Branch, is a river system located on Cape York Peninsula in Far North Queen ...
*''Pseudocheirus peregrinus convolutor'', (Eastern ringtail possum or Southeastern ringtail possum)
*''Pseudocheirus peregrinus pulcher'', (Rufous ringtail possum)
*''
Pseudocheirus peregrinus occidentalis
The western ringtail possum or ngwayir refers to a species of possum, ''Pseudocheirus occidentalis'', found in a small area of Southwest Australia. They are a cat-sized marsupial with a stocky build, dark greyish-brown fur, pale underparts and ...
'', called the Western ringtail possum, found in the south west of the country. Taxonomic opinion favours regarding this as a separate species, ''Pseudocheirus occidentalis'', though the currently contradictory evidence would not allow this recommendation to be formalised.
Description
The common ringtail possum weighs between and is approximately cm long when grown (excluding the tail, which is roughly the same length again). It has grey or black fur with white patches behind the eyes and usually a cream-coloured belly. It has a long
prehensile
Prehensility is the quality of an appendage or organ (anatomy), organ that has Adaptation (biology), adapted for grasping or holding. The word is derived from the Latin term ''prehendere'', meaning "to grasp". The ability to grasp is likely der ...
tail which normally displays a distinctive white tip over 25% of its length. The back feet are
syndactyl
In biology, dactyly is the arrangement of digits (fingers and toes) on the hands, feet, or sometimes wings of a tetrapod animal. It comes from the Greek word δακτυλος (''dáktylos'') = "finger".
Sometimes the ending "-dactylia" is use ...
, which helps it to climb. The ringtail possum's molars have sharp and pointed
cusps.
Distribution and habitat
The common ringtail possum ranges on the east coast of Australia, as well as Tasmania and a part of southwestern Australia.
[Pseudocheirus peregrinus]
Animal diversity They generally live in temperate and tropical environments and are rare in drier environments. Ringtail possums prefer forests of dense brush, particularly
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 ...
forests.
[ The common ringtail possum and its relatives occupy a range of niches similar to those of lemurs, monkeys, squirrels, and bushbabies in similar forests on other continents.][Barnett, J.L, A., R. R.A. How. 1984. "The Population Biology of Pseudocheirus peregrinus". pp. 261–268 in ''Possums and Gliders'' Andrew Smith, Ian D. Hume (Eds.) New South Wales: Surrey Beatty & Sons Pty Limited.] It is less prolific and less widespread than the common brushtail possum
The common brushtail possum (''Trichosurus vulpecula'', from the Greek for "furry tailed" and the Latin for "little fox", previously in the genus ''Phalangista'') is a nocturnal, semiarboreal marsupial of the family Phalangeridae, native to Austr ...
.
Behaviour
The common ringtail possum is nocturnal and well adapted to arboreal life. It relies on its prehensile tail and sometimes will descend to the ground.[ They communicate with soft, high-pitched, and twittering calls.
]
Diet and foraging
The common ringtail possum feeds on a wide variety of plants in the family Myrtaceae
Myrtaceae, the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All speci ...
including the foliage, flowers and fruits from shrubs and lower canopy. Some populations are also known to feed on the leaves of cypress pine (''Callitris
''Callitris'' is a genus of coniferous trees in the Cupressaceae (cypress family). There are 16 recognized species in the genus, of which 13 are native to Australia and the other three (''C. neocaledonica, C. sulcata'' and ''C. p ...
''), wattles (''Acacia
''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus na ...
'' spp.) and plant gum or resins.
When foraging, ringtail possums prefer young leaves over old ones. One study found the emergence of young possums from their pouches corresponds to the flowering and fruiting of the tea-tree, ''Leptospermum
''Leptospermum'' is a genus of shrubs and small trees in the myrtle family Myrtaceae commonly known as tea trees, although this name is sometimes also used for some species of ''Melaleuca''. Most species are endemic to Australia, with the greate ...
'' and the peak of fresh plant growth.[ Young eucalypt leaves are richer in nitrogen and have less dense cell walls than older leaves; however, the protein gained from them is less available due to higher amounts of tannins. When feeding, the possum's molars slice through the leaves, slitting them into pieces. The possum's caecum separates the fine particles from the coarse ones.][ These particles stay in the caecum for up to 70 hours where the cell walls and tanned cytoplasts are partially digested.
What distinguishes the digestive system of the common ringtail possum from that of the koala and the greater glider is the caecal content transfers directly back to the stomach. Because of this, the ringtail possum is able to gain more protein.][ This is also done by ]lagomorph
The lagomorphs are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae (hares and rabbits) and the Ochotonidae (pikas). The name of the order is derived from the Ancient Greek ''lagos'' (λαγ ...
s like rabbit
Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit speci ...
s and pika
A pika ( or ; archaically spelled pica) is a small, mountain-dwelling mammal found in Asia and North America. With short limbs, very round body, an even coat of fur, and no external tail, they resemble their close relative, the rabbit, but wi ...
s. Hard faeces are produced during the night while feeding and are not eaten, while soft faeces are produced during the day during rests and are eaten.
Metabolism
The re-ingestion of caecal content also serves to maintain the ringtail possum's energy balance. Ringtail possums gain much of their gross energy from reingestion. The common ringtail possum has a daily maintenance nitrogen requirement (MNR) of 290 mg N/kg0.75. Common ringtail possums gain much of their MNR from consuming their nitrogen-rich caecal pellets. They would have to gain 620 mg N/kg0.75 otherwise.[ The ringtail possum recycles 96% of its liver's urea, which is then transferred into the caecum and made into bacterial protein. Only re-ingestion makes this effective and the bacterial protein must be digested in the stomach and the amino acids subsequently absorbed in the small intestine.][ This recycling also allows the possum to conserve water and urinate less. Reingestion allows the possum to live on low nitrogen eucalyptus leaves which is particularly important during late lactation. It has been found that at higher temperatures, the common ringtail possum consumes less food due to a limited ability to metabolize ]toxin
A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849– ...
s found in their diet. Because 55% of their water intake comes from the leaves and foliage they consume, their metabolic rate
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
must remain low and stable while facing water loss. In response to this challenge, common ringtail possums can control their body temperature and conserve water by using facultative hyperthermia to temporarily raise their internal body temperature, ranging from .
Nesting
Common ringtail possums live a gregarious
Sociality is the degree to which individuals in an animal population tend to associate in social groups (gregariousness) and form cooperative societies.
Sociality is a survival response to evolutionary pressures. For example, when a mother wasp ...
lifestyle which centres on their communal nests, also called dreys. Ringtail possums build nests from tree branches and occasionally use tree hollows. A communal nest is made up of an adult female and an adult male, their dependant offspring and immature offspring of the previous year.[ A group of ringtail possums may build several dreys at different sites. Ringtail possums are territorial and will drive away any strange conspecifics from their nests. A group has a strong attachment to their site. In one experiment, in which a group was removed from their territory, it remained uncolonised for the following two years.][ Ringtail possum nests tend to be more common in low scrub and less common in heavily timbered areas with little under-story.][ Dreys contribute to the survival of the young when they are no longer carried on their mother's back.][
]
Reproduction and growth
As a marsupial, the common ringtail possum carries its young in a pouch, where it develops. Depending on the area, the mating season can take place anywhere between April and December.[ The majority of the young are born between May and July. The oestrous cycle of ringtail possum lasts 28 days.][ It is both polyoestrous and polyovular. If a female prematurely loses her litter, she can return to oestrous and produce a second litter in October as a replacement if conditions are right.][ The average litter is two, although there are very occasionally triplets.][ Common ringtail possum young tend to grow relatively slowly due to dilute milk with low lipid levels that is provided to the young. As with other marsupials, the common ringtail possum's milk changes through lactation.] During the second phase of lactation, more solid foods are eaten, especially when the young first emerges from the pouch.[ During this time, the concentration of carbohydrates fall, while those of proteins and lipids reach their highest.][ The long lactation of the ringtail possums may give the young more time to learn skills in the communal nest as well as to climb and forage in the trees.][
The young are first able to vocalise and open their eyes between 90 and 106 days of age.][ They leave their mother's pouch at 120–130 days. However, lactation usually continues until 180–220 days after birth but sometimes ends by 145 days.][ Both sexes become sexually mature in the first mating season after their birth.
]
Status
Common ringtail possum populations severely declined during the 1950s. However, populations seem to have recovered in recent times.[ Because they are largely arboreal, common ringtail possums are particularly affected by ]deforestation in Australia
Land clearing in Australia describes the removal of native vegetation and deforestation in Australia. Land clearing involves the removal of native vegetation and habitats, including the bulldozing of native bushlands, forests, savannah, woodlands ...
. They are also heavily predated upon by the introduced red fox
The red fox (''Vulpes vulpes'') is the largest of the true foxes and one of the most widely distributed members of the Order (biology), order Carnivora, being present across the entire Northern Hemisphere including most of North America, Europe ...
. They are also hit by cars, or killed by snakes, cats and dogs in suburban areas.[
]
References
{{Taxonbar, from=Q928390
Mammals of New South Wales
Mammals of Queensland
Mammals of South Australia
Mammals of Tasmania
Mammals of Victoria (Australia)
Possums
Mammals described in 1785