The Ring-tailed Possum

(Pseudocheirus peregrinus)

Please click on thumbnails to enlarge

Description and Distinguishing Features:

The scientific name of this delightful little creature is a bit of a mouthful and is pronounced ‘syue-doh-kie-rus  pe-re-green-us’ and means ‘false-hand from foreign parts’.

The smallest of the ringtail possums, it has variable grey to brown to blackish fur, with a long tapering prehensile tail, of which at least a third is always white.   Even on the darkest of nights, this feature is very noticeable under torchlight and it would be difficult to confuse it with any other arboreal animal.    The tail has a long friction pad on its underside and is used as a fifth limb when climbing and also to carry nesting material.      When not in use during the night, and also when the possum is sleeping, the tail is held tightly curled.     The head and body are from 300 to 350 mm, with the tail also between 300 to 350mms.     The weight of an adult animal can vary from 700gms to about 1100gms.     The ears are short and rounded and have a patch of white behind them.    They have long sensitive whiskers (vibrissae) and a relatively well developed sense of smell for an arboreal animal.

The manus or hand has five 5 toes, all of which are clawed, with digits one and two being opposed.    The pes or foot also has five toes, with a large opposable thumb (or clawless hallux), the other four digits are all clawed and digits two and three are joined.     These possums tend to make more use of their powerful hind feet rather than their small front feet when moving through the trees.    They also make extensive use of their prehensile tail.

The John Gould print of the Common Ringtail Possum Pseudocheirus peregrinus (formerly known as Phalangista viverrina) courtesy of and with acknowledgments to Museum Victoria

Common Ringtail Possums are almost entirely arboreal, and climb by simple bounds, jump well and crawl amongst branches.   On the ground, they move on all fours – quadrupedally.     They can also swim well. 

They have selendontic dentition – their molar teeth have sharp, triangular or crescentic ridges on them.  This enables them to finely grind tough leaves before swallowing them.

They have a soft, high-pitched twittering chirrup, a chattering alarm call and make harsh grunts when fighting.  The young sometimes make a repetitive shrill chirruping call, which is almost bird-like.      They have a life span of about five years in the wild, but may live slightly longer in captivity.

Distribution, Status and Habitat:

They have the widest distribution of the ringtails, being the only petaurid to inhabit Tasmania and some Bass Strait Islands.     They occur right along Eastern Australia, from the tip of Cape York down to south eastern South Australia, in to the Mt Lofty and also Kangaroo Island, where they were introduced.     The species has a total range of something over 1 million square kilometers and is therefore considered widespread and fairly common within their range.    They are considered to be secure.

They occur in a variety of habitats, including areas of rainforest, scrub and woodland, open and closed forests and also coastal dunes, provided adequate shrubby cover is available.  They have adapted well to live quite happily in domestic gardens, nesting in trees and even house roofs and taking advantage of a wide range of introduced flowers and fruit for their diet.

During breeding season, they build spherical nests of leaves, ferns and twigs, with a side entrance 76 - 175 mm in diameter, in leafy saplings or shrubs, sometimes saddling them on a tree branch or in a hollow.    The nests, sometimes called “dreys” may be lined with shredded bark or grass.    However, in the north, they usually sleep in tree hollows, which may sometimes be lined with dry leaves.    They may have up to 8 of these nests in their home range.

Not overly aggressive although we often come upon individual who will show abhorrent behaviour.    They are nocturnal, sleeping by day in their nest.    Most active in the first part of the night, they will then rest, before resuming feeding just prior to dawn.    They secrete a strong smelling liquid from anal glands when handled.    Gregarious, they live in family groups, generally consisting of I adult male, 1 or 2 females, progeny of the year and young of the previous year and they will communicate vocally.     The average home range of a family group is 0.37 hectares. (0.9 acre).     The home range of a male will overlap the home ranges of several females, and dreys (or nests) may be in close proximity to one another.    Large trees or dense thickets may contain several dreys.

Their diet varies considerably according to availability within their geological range, but consists primarily of Eucalypts other native and cultivated plant leaves, blossoms, flowers (like roses & hibiscus), buds and soft native and orchard fruit. For this reason they are often persecuted, or at least ‘unloved’ by gardeners.     They do not eat insects.

The Common Ringtail Possum is one of a variety of marsupials able to eat Eucalypt leaves, which are very poor in nutritional value and difficult to digest. They are only able to do this as their gut has evolved to cope with this, by their colon becoming larger and their caecum even larger.    Here, the chewed leaves are fermented by a variety of differing bacteria, with fluid and fine particles being retained in the caecum longer than coarser particulate matter.    Once a day, while resting in its nest, the Possum passes the caecum contents as soft faeces, which it eats.    This second “turn” at eating enables the possums to extract any remaining nourishment from its food.    At weaning, the young also eat these soft faeces, which aids in the establishment of their gut flora.     At night, when they are active, they pass hard faeces, which consist of the coarser particles from their diet and twice digested material.     Their selenodonty is an adaptation which assists their digestive process.

Reproduction:

Common Ringtails Possums are sexually mature at between 13 and 18 months and may live for 5 years or more in the wild.

The pouch is well developed with a forward opening and has 4 nipples, but usually only the posterior pair is functional.     The usual litter is 2, but 1 is common, and 3 and 4 have been recorded.   After scouring a multitude of sources there seems to be a gap in our knowledge of the gestation period for this animal.    It has been suggested that it would probably be around the thirty day mark but I can find no scientific reference to this anywhere.    (If anyone can help I would be pleased to hear from you, with a note of your reference source – please email the Ed).

They breed from April to November, with usually 1 litter a year in Victoria, and 2 elsewhere.    The newborn attach to nipples for 42 to 49 days and then stay in the pouch until about 4 months, (125 to 130 days) but are not weaned until they are after 6 months old - 180 to 210 days.    They either stay in the nest or cling to their mother’s back after they leave the pouch, but their care is often shared by their father.

In Captivity

Single animals of this species can become quite tame if treated well and with heaps of TLC.     However, as with all Australian possums they have a habit of ‘marking’ their territory which can become quite overpowering in confined spaces and it will only exacerbate the situation if you insist on ‘cleaning up’ after them.   All this does is to encourage them to scent mark again and with renewed vigour.    However, not being a strong believer of keeping one of anything I would suggest they are best kept as pairs in an outdoor aviary of fairly large dimensions; say not less than 3.7m (12ft) long by 2.4m (8ft) high by 1.2m (4ft) wide, height being the most important as these animals are primarily arboreal.   The height should leave plenty of room for them to climb around the aviary well above your head.

Their diet should consist of fruit, nuts, greens, oats, flowers and flower petals both native and exotic (but careful with exotics - don’t give anything likely to be poisonous - like Oleander for example) and Australian native vegetation.   Unlike the Brush tailed Possum (Trichosurus vulpecula) it is most important that Ringtails get lots of native vegetation in their diet to ensure a long and healthy life and is essential if you wish them to breed.    This should be provided on a regular basis and could form part of your normal garden pruning regime.   If you maintain a high proportion of native vegetation in the diet they will probably live for ten or twelve years in captivity and will be quite happy to live as small family groups.

Ringtail Possum in an obviously captive environment.    Please note the extensive white portion of the tail.   This is a major distinguishing feature of this animal when viewed from a distance, especially at night

Fresh water must be available at all times and a number of nesting logs or boxes should be provided and they should exceed the number of animals within the aviary.   This will ensure a choice of sleeping quarters and will assist in the reduction of any squabbles that might ensue.

On occasions it has been known for some animals to become extremely aggressive and will literally fly out their log or box at any intruder within their territory.    If you are unfortunate enough to have one of these animals it may be a good idea to arrange a small door in the side of the aviary for feeding purposes as sometimes they can be so bad that you have can sustain some quite nasty injuries when entering the aviary and extreme caution is advised.

Subspecies:

P. peregrinus peregrinus – Cape York (Queensland) to Kangaroo Island (SA)

P. peregrinus cooki - coastal scrub of south-eastern mainland.

P. peregrinus convolutor – Tasmania and Bass Strait Islands

P. peregrinus pulcher – south-eastern Queensland and north-eastern New South Wales rainforest.

Bibliography

Strahan, R. (1998) The Mammals of Australia. Australian Museum, Reed New Holland.

Cronin, L. (1991) Key Guide To Australian Mammals.  Reed Books, Australia.

Morcombe, I and M., (1975), Reed Books.

Hyatt, J. and Shaw, N. (1980), Australian Mammals – A Field Guide for New South Wales, Victoria, South Australia and Tasmania. Thomas Nelson Australia.

Troughton, E. (1973) Furred Animals of Australia. Angus and Robertson.