General

To urban dwellers the Brushtail Possum is arguably be the best known Australian marsupial other than the Kangaroo or Koala.    They range in size from that of a

small cat (the Northern Brushtail) to small dog size of the Tasmanian Brushtail.    Although all these animals are predominantly arboreal, they spend a lot of their time foraging on the ground, unlike the Ringtail Possum (Pseudocheirus peregrinus) which is strictly arboreal except when finding it necessary to move down to the ground to access another nearby tree.

These animals have settled well into urban life, much to the chagrin of many householders but there is some concern for there well-being in the ‘wild’.     They were also introduced into New Zealand around 170 years ago and have subsequently become an enormous ecological problem causing untold damage to the environment.     There have been several concerted efforts to wipe them out, all of which have failed, but their pelts still support a multi-million dollar industry in that country.

There are three extant species:

·       1.       The Common Brushtail Possum, Trichosurus vulpecula.

Trichosurus is derived from the Greek, trix, hair and oura, tail: and vulpecula from the Latin vulpes, fox and ecula, diminutive suffix.

which has three subspecies:

·     (i).     Trichosurus vulpecula vulpecula - found in the central and south-western mainland

·     (ii).    Trichosurus vulpecula johnstoni - found in eastern and northern Queensland

·     (iii).   Trichosurus vulpecula fuliginosus - exclusive to Tasmania and is the largest of this family group (pictured at the head of this article).

·       2.       The Mountain Possum, or Bobuck, Trichosurus caninus.
caninus is taken directly from the Latin caninus - dog like. 

·       3.       The Northern Brushtail Possum, Trichosurus arnhemensis.
arnhemensis is taken from its natural home range i.e. Arnhem Land.

Appearance

Click on thumbnail to enlarge

The brush-tailed possum is found in a wide array of colours, from a pale smoky grey of the tropical animal T. arnhemensis through to a dark chocolate brown of the Tasmanian animal T. v. fuliginosus.  There is also a white, or more correctly yellow, colour mutation sometimes known as the golden possum (see picture at right).

The Common Brushtail, T. vulpecula, (see picture at end of article “The Fate of Translocated Urban Possums”) is generally light to dark grey above with a lighter (almost to white) underbelly with a long bushy tail, usually black.  The male has a dark stripe on his chest which is the result of secretions from scent glands with which he marks his territory. The underneath of latter half of the tail is bare to assist in its arboreal activities.    It is also semi prehensile.

Of the subspecies, T. v. johnstoni is known as the Copper Possum, because of its coppery red/brown colour, and in some respects very similar in colour to the Tasmanian Brushtail but is much smaller and the fur is shorter and thicker.   It feels very much like velvet to the touch.

The Tasmanian Brushtail, T. v. fuliginosus is the ‘big boy’ of the possum world.    It is a very large animal, say, up to that of a small dog, and generally dark chocolate brown blending to a coppery red underneath.   It has very long and very thick fur.

The Mountain Brushtail Possum or Bobuck, T. caninus, is similar to the Common Brushtail but can be recognised as the larger animal in areas where the two species co-habit.  It is more evenly coloured than the common brushtail, having less white underneath and it also lacks the scent gland markings.

The Northern Possum, T. arnhemensis, is again basically a similar to the Common Brushtail (T. vulpecula) although generally a much lighter shade of grey.   It is also the smallest of the brushtails but its main distinguishing feature is that it does not have the bushy tail found on the others. (see picture at right).   The tail is more reminiscent of the Ringtail Possum (Pseudocheirus peregrinus) although lacking any white markings.

Distribution

If you include all the species and subspecies, they cover pretty much most of the country.

The Common Brushtail, Trichosurus vulpecula, is by far the most widespread of the brushtail possums.  It inhabits most of eastern Australia from far north Queensland right through New South Wales, all of Victoria, and into the southern half of South Australia where suitable habitat exists.

The Mountain Brushtail Possum or Bobuck, Trichosurus caninus, is found along the coastal strip of southeastern Australia from southern Queensland through New South Wales and into eastern parts of Victoria.  Its range is also inhabited by T. vulpecula.

The Northern Brushtail Possum, Trichosurus arnhemensis, is found north of the Tropic of Capricorn in Western Australia, the Northern Territory and just creeps into the north-west tip of Queensland where there is suitable habitat.

Of the subspecies, T. v. vulpecula is found in central Australia centering on the Alice Springs region and in the southwest corner of Western Australia.     T. v. johnstoni, or the Copper Possum, is found in a small region in the north-east of Queensland and T. v. fuliginosus or Tasmanian Brushtail, as its name suggests, is found only in Tasmania.

Habitat & Diet

These animals inhabit a variety of terrains provided there are suitable trees to supply them with a source of food and hollows in which to sleep.  Being very adaptable animals some populations have become urbanised, living in man-made structures and scavenging from gardens, dustbins and refuse tips.  Even though the brushtail possum is generally vegetarian they will eat just about anything.  In the wild they will favour native flowers, fruits, nuts, fungi and a variety of green vegetation.  However, they will also eat grubs, insects, and moths and actively seek other sources of protein.  They are also known to feed on carrion.

Captive Husbandry

Brushtails are comparatively easy to keep in captivity provided you stick to a few common sense rules.  They need an aviary with a reasonable amount of space and plenty of branches for them to climb over and run along.  They should also be offered a selection of sleeping quarters such as hollow logs or boxes.  As a rule of thumb, always provide one more box or log than there are inhabitants of the aviary.  In this way they will always have a choice and it avoids, or at least reduces, the chances of fighting.   These animals are highly territorial so care must taken when introducing new animals into an existing situation as they can be extremely pugnacious towards one another.   This means, if you are going to keep more than one in an aviary it is essential that they are compatible.    Likewise if you're going to breed these animals in captivity it is also essential that a close eye is kept on any offspring for signs of aggression by the adults.   Horrific injuries and even death can result.

If you keep these animals in an aviary in suburbia some thought should also be given to your neighbours.    Brushies can be very vocal with a range of sounds from a loud hissing to deep growling coughs and if you are keeping breeding pairs, during the mating ritual you can expect a lot of this sort of behaviour as well as them chasing one another around the aviary.    To the uninitiated this can sound a bit like world war three or at the very least a heard of stampeding elephants about to land on your doorstep.

A captive diet is comparatively simple.    They will do very well on diet of fruit, nuts, vegetables and native vegetation in the form of branches from eucalypts, callistemon, or grevillea and so on.    If you are growing native trees and shrubs in your garden, the prunings from these will be readily accepted.    They are also fond of grain bread, cakes and pastries although I would not advocate these as a staple, but just as treats.    With regard to the types of fruits and vegetables you offer them, maybe I should put it this way; if you are prepared to eat it then the possums will probably enjoy it also.    In addition it would not do any harm to offer the occasional chop bone (or similar) for them to chew on to introduce some additional protein into their diet.

Breeding

Females become sexually active at around one year of age and will produce offspring annually although on occasions they will produce twice yearly.     The female has two teats in her pouch but only a single young is born around 17 days after mating and it attaches itself to one of the teats where it remains for the next four to five months.    After pouch emergence the young will remain with its mother for up to a couple of months, riding on her back and suckling from the pouch when necessary.     After the young are weaned they have to find their own way in life at which time there is a very high mortality rate.    The brushtail being highly territorial, the young, and young males in particular, are ostracised from their home range and often fall prey to creatures like the Powerful Owl (Ninox strenua) and Barking Owl (Ninox connivens) as well as introduced predators like the fox, the cat (both feral and domestic) and the domestic dog.

This article is also a must read particularly if you are considering applying for permission to relocate a problem possum
TThe Fate of Translocated Urban Possums

References

Strahan, Ronald (1983) edited by “The Complete Book of Australian Mammals” published by Angus & Robertson.

Cayley, Neville (1987) “What Animal is That” published by Angus & Robertson

But wait there’s more……

In addition to the foregoing, the following is information available from a National Parks and Wildlife Service of South Australia.  This is a reprint of their information leaflet No 6 for which offers some useful additional information…..

The common brushtail possum (Trichosurus vulpecula) is about the same size as a domestic cat.  In South Australia the dense fur varies from light to dark grey on the back, and is pale on the underbelly.  The thick brushy tail, which is usually darker in colour than the body, narrows at the tip and tends to be bare on the lower surface.

The brushtail is a nocturnal, tree-living animal, but may also be seen on the ground.  It should not be confused with the less common ringtail possum which is kitten sized with a characteristic tapering tail which is white at the end.  Both possums can curl their tails to grip branches.

Although brushtail possums have disappeared from much of their range in the drier parts of South Australia, where they were common when Europeans first arrived, they still occur in the wetter areas in a range of habitats from woodland to farmland.  They have increasing numbers in the metropolitan area of Adelaide and some other towns because daytime shelter in the form of house roofs and the hollows of large exotic trees, and to such as the food garden trees and plants, has been provided.

Brushtail possums usually breed in autumn and spring.  They have a single young which spends four to five months in the pouch, followed by one to two months suckling and riding on the mothers back.

During the next 12 months, juveniles disperse from the birthplace in search of new territories.

Food and shelter in urban areas

Brushtail possums eat a wide variety of foods such as the shoots and fruit of native and exotic trees and shrubs.  Other food includes rose petals and hips, a variety of vegetables, and pasture grasses.  They also the insects and occasionally meat.  They cannot exist on an exclusive diet of gum leaves because their metabolism cannot cope with the toxic compounds the leaves contain.

Brushtail possums unfortunately often take refuge in roofs and eaves of houses and other buildings, as well as tree hollows.

Protection

Brushtail possums are native animals and are protected under the National Parks and Wildlife Act, 1972-81.  You must obtain a permit if you wish to trap or euthanase them.  You can get a free permit from the nearest office of the National Parks and wildlife service, or from many council offices.

Removing possums from under roofs

Possums are active at night, and they may be heard scurrying with a heavy thumping gait across the roof or in the ceiling.  They also make a noise similar to a person breathing heavily and call with a series of deep, guttural coughs.  Occasionally the sounds made by rats in the ceiling may be mistaken for those of possums.  However, rats make a 'pitter-patter' sound in comparison with the heavy thumping noise of brushtail possums.

Trapping

Open mesh traps can be used to catch possums.  These traps can be hired for a free from various locations including your local council.  Traps may also be purchased from some hardware stores.  The best way to trap a possum is by luring it to the area a couple of days before placing the trap.  A bait of apple, or bread spread with honey or peanut paste, securely fixed to the hook, may entice the possum into the trap.  Other fruit may also be effective.  Check the trap daily to ensure that the trapped animal does not suffer.

Trapped possums should be killed humanely.  If they are released somewhere else they may cause the same problem to another householder.  If you strongly object to having the possum humanely killed, you may release it on private property with the permission of the property owner.  NATIONAL PARKS AND METROPOLITAN PARKS are not suitable as this will only disrupted existing established possum territories and my also displays owls or other native animals from tree hollows.  Pest control firms listed in the Yellow Pages telephone directory will trap and kill possums for a fee.

Possum proofing

After you have removed the possum from your premises (roof, ceiling etc.), seal the points where it is likely to have entered to prevent other possums entering in the future.  Do not seal entry points until you are sure that there are no possums inside.  Otherwise any trapped possums will die a slow, cruel death, and its body will create an unpleasant smell for weeks.

It may also be worthwhile to cut off access to the roof by lopping overhanging branches or placing a sheet metal collar around the trunks of trees next to the house.  Collars should be at released 600mm wide and 600mm above the ground.

Possum nest boxes

An alternative to trapping and removing possums from your property is to supply them with an alternative home site to your roof.  Possums, like cats, are territorial.  A nest box placed high in a tree, protected from draughts, direct sun and rain, will provide a suitable home for your resident possum.  Other possums may then be discouraged from entering your property.

Nest boxes can be built out of scrap timber to the size shown in the illustration.  The timber should be rough-sawn so possums can get a grip on it and should be 19-25mm thick to provide installation.

Do not use:

·       Treated timber

·       toxic plants

·       chipboard

·       Strong-smelling glues or adhesives

·       sheet metal on the lid

Design

The entrance hole should be big enough to allow the intended resident to enter.  Inside walls must be rough so that young possums can climb out.

The lid should be hinged to enable you to inspect and clean the box periodically and should be secured with a simple click.  For weather protection, the lid must slope from the back and overhang the front by about 25mm.  It should also overhang both sides of the box.

Placing

The box should be placed at least three metres above the ground, high enough in the tree to prevent domestic pets interfering with the possum.

Locate the box on the south-facing sides of the tree, protected from draughts direct sun and rain stopped

Fixing

Fix a mounting strip to the back of the box to make it easier to attach to the trunk.  Pre-drill nail holes to prevent splitting and use 100millimetre galvanised flathead nails.  The box must be stable and upright, with the entrance hole on the left or right side of the box next to the tree trunk or branch

Remember:

·     do not disturb native animals once they are using the box as some breeding animals may abandon their young.

·     Brushtail possums are wild native animals, so don't expect them to become as tame and friendly as domestic pets.

·     Beware of unwanted tenants such as sparrows and starlings.  These aggressive introduced birds can, if unchecked, takeover the box intended for the possum.

References

The second half of this article is a reprint of leaflet No 6 from the National Parks and Wildlife Service of South Australia and is reproduced herewith with their kind permission

Strahan, Ronald (1983) edited by “The Complete Book of Australian Mammals” published by Angus & Robertson.

Cayley, Neville (1987) “What Animal is That” published by Angus & Robertson