Mountain Brushtail Possum
Encyclopedia
The Mountain Brushtail Possum, or Southern Bobuck (Trichosurus cunninghami), is a nocturnal, semi-arboreal marsupial
of the family Phalangeridae
native to southeastern Australia. It was not described as a separate species until 2002.
. The southern population, prevalent in the Victoria
n Alps
was to retain its already designated common name Mountain Brushtail Possum but assigned a new binomial, T. cunninghami. However, genetic divergence between T. caninus and the putative T. cunninghami may not support a case for the establishment of a new species.
In 2005 a colony of bobucks was discovered in swamp coastal habitat in South West Gippsland, Victoria. A follow up biodiversity survey uncovered a widespread yet previously unrecorded population of bobucks in coastal habitat and parts of inland Gippsland.
In view of these findings, the currently accepted name, "Mountain" Brushtail Possum, is no longer accurately descriptive. One suggestion is to rename the northern group as the "Northern Bobuck" and the Victorian animals as "Southern Bobuck", T. cunninghami.
of eastern Australia from southern Victoria to south-eastern Queensland
. They typically dwell at altitudes greater than 300 metres. Bobucks are medium-sized (2.5 – 4.5 kg),semi-arboreal, nocturnal marsupials.
, T. vulpecula. As a result the Common Brushtail Possum has been able to colonise a greater variety of habitats than either of its Bobuck relatives. For example, unlike Common Brushtails, Bobucks are not known in urban areas and have been thought of as being obligately adapted to stable forest environments.
During the day, the Mountain Brushtail Possum dens in tree hollows (or sometimes in dense ground cover) and at night emerges to forage. In mountain country the Mountain Brushtail Possum is reported to depend mainly upon Acacia
species for its diet and in particular the Silver Wattle
, Acacia dealbata. However, in lowland Gippsland there is no association of these animals with any particular type of vegetation: it is to be found in a variety of Eucalypt
species stands or the Tea Tree
. The Mountain Brushtail Possum is known to feed at ground level and they are able to utilise hypogeal and epigeal fungi as well as ground-level plants food resources.
The Mountain Brushtail Possum is also reported to require tree hollows for use as dens. Indeed both the easy availability of hollow-bearing trees and Silver Wattle are thought to determine the population density and distribution of the Mountain Brushtail Possum in Victoria.
Its longevity is amazingly high: in fact it is perhaps the longest lived marsupial species.
Recent research indicates that the mating system of the Mountain Brushtail Possum is variable. Intensive study of two Mountain Brushtail Possum populations found that one of these populations was polygynous, while the other was monogamous. The two populations lived within 2 km of each other, yet the group dwelt in a linear habitat strip along a roadside that had escaped logging for over 100 years, whereas the monogamous population inhabited a forest patch that had been logged 40 years ago. To date it remains unclear whether this difference in mating system is because of the geographical shape of the habitat or the quality of its resources.
Marsupial
Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...
of the family Phalangeridae
Phalangeridae
Phalangeridae is a family of nocturnal marsupials native to Australia and New Guinea, including the cuscuses, brushtail possums, and their close relatives...
native to southeastern Australia. It was not described as a separate species until 2002.
Taxonomy
In 2002, based upon morphometric differences, it was proposed that the Mountain Brushtail Possum, Trichosurus caninus, be reclassified into two distinct species. The northern form was to retain the binomial name T. caninus but was henceforth to be known as the Short-eared PossumShort-eared Possum
The Short-eared Possum is a species of marsupial in the Phalangeridae family. It is endemic to Australia.Found north of Sydney the species was once classed as a Mountain Brushtail Possum for which is its closest relative....
. The southern population, prevalent in the Victoria
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....
n Alps
Australian Alps
The Australian Alps are the highest mountain ranges of mainland Australia. They are located in southeastern Australia and straddle the Australian Capital Territory, south-eastern New South Wales and eastern Victoria...
was to retain its already designated common name Mountain Brushtail Possum but assigned a new binomial, T. cunninghami. However, genetic divergence between T. caninus and the putative T. cunninghami may not support a case for the establishment of a new species.
In 2005 a colony of bobucks was discovered in swamp coastal habitat in South West Gippsland, Victoria. A follow up biodiversity survey uncovered a widespread yet previously unrecorded population of bobucks in coastal habitat and parts of inland Gippsland.
In view of these findings, the currently accepted name, "Mountain" Brushtail Possum, is no longer accurately descriptive. One suggestion is to rename the northern group as the "Northern Bobuck" and the Victorian animals as "Southern Bobuck", T. cunninghami.
Description
Both the Mountain Brushtail Possum, T. cunninghami, and its cousin the Short-eared Possum, T. caninus, are generally reported to inhabit wet sclerophyll forest in south-eastern Australia along and to the south and east of the Great Dividing RangeGreat Dividing Range
The Great Dividing Range, or the Eastern Highlands, is Australia's most substantial mountain range and the third longest in the world. The range stretches more than 3,500 km from Dauan Island off the northeastern tip of Queensland, running the entire length of the eastern coastline through...
of eastern Australia from southern Victoria to south-eastern 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...
. They typically dwell at altitudes greater than 300 metres. Bobucks are medium-sized (2.5 – 4.5 kg),semi-arboreal, nocturnal marsupials.
Diet and habitat
Habitat and dietary requirements of both the Mountain Brushtail Possum and the Short-eared Possum are reported to be more specialised than those of their close relative the Common Brushtail PossumCommon Brushtail Possum
The Common Brushtail Possum is a nocturnal, semi-arboreal marsupial of the family Phalangeridae, it is native to Australia, and the largest of the possums.Like most possums, the Common Brushtail is nocturnal...
, T. vulpecula. As a result the Common Brushtail Possum has been able to colonise a greater variety of habitats than either of its Bobuck relatives. For example, unlike Common Brushtails, Bobucks are not known in urban areas and have been thought of as being obligately adapted to stable forest environments.
During the day, the Mountain Brushtail Possum dens in tree hollows (or sometimes in dense ground cover) and at night emerges to forage. In mountain country the Mountain Brushtail Possum is reported to depend mainly upon Acacia
Acacia
Acacia is a genus of shrubs and trees belonging to the subfamily Mimosoideae of the family Fabaceae, first described in Africa by the Swedish botanist Carl Linnaeus in 1773. Many non-Australian species tend to be thorny, whereas the majority of Australian acacias are not...
species for its diet and in particular the Silver Wattle
Silver wattle
Silver wattle is the common name of two plant species:* Acacia sclerosperma* Acacia dealbata...
, Acacia dealbata. However, in lowland Gippsland there is no association of these animals with any particular type of vegetation: it is to be found in a variety of Eucalypt
Eucalypt
Eucalypts are woody plants belonging to three closely related genera:Eucalyptus, Corymbia and Angophora.In 1995 new evidence, largely genetic, indicated that some prominent Eucalyptus species were actually more closely related to Angophora than to the other eucalypts; they were split off into the...
species stands or the Tea Tree
Tea tree
Tea tree or Ti-tree is a popular name that has been applied to a number of different, unrelated plants:*Camellia sinensis , from which black, green, oolong and white tea are all obtained....
. The Mountain Brushtail Possum is known to feed at ground level and they are able to utilise hypogeal and epigeal fungi as well as ground-level plants food resources.
The Mountain Brushtail Possum is also reported to require tree hollows for use as dens. Indeed both the easy availability of hollow-bearing trees and Silver Wattle are thought to determine the population density and distribution of the Mountain Brushtail Possum in Victoria.
Reproduction
The Mountain Brushtail Possum shows little sexual dimorphism. Mating occurs within a 2-3 week period during autumn (March–June). Female oestrus is highly synchronised, and most females will give birth to one offspring each year. Males do not appear to provide any care to the young. The young emerge from the pouch after several months and are then carried on the back of their mother. Over the summer (December to February), young begin to accompany their mothers on foot as a first step, as it were, to full independence. Neither males nor females will reproduce until they are at least two years of age. There is evidence that female offspring are often philopatric while young males have been found to disperse up to 8 km. Upon reaching reproductive maturity, the Mountain Brushtail Possum will retain the same home range for life.Its longevity is amazingly high: in fact it is perhaps the longest lived marsupial species.
Recent research indicates that the mating system of the Mountain Brushtail Possum is variable. Intensive study of two Mountain Brushtail Possum populations found that one of these populations was polygynous, while the other was monogamous. The two populations lived within 2 km of each other, yet the group dwelt in a linear habitat strip along a roadside that had escaped logging for over 100 years, whereas the monogamous population inhabited a forest patch that had been logged 40 years ago. To date it remains unclear whether this difference in mating system is because of the geographical shape of the habitat or the quality of its resources.