Geographic Range
Mountain brushtail possums, or southern bobucks, are native to southeastern Australia,
ranging from Victoria to Central Queensland.
- Biogeographic Regions
- australian
Habitat
Mountain brushtail possums are semi-arboreal marsupials found in wet sclerophyll forests
of southeastern Australia (Lindenmayer, Dubach, and Viggers, 2002). They usually live
in above-ground dens (either tree hollows or nest boxes). A recent study by J.K. Martin
found that adult bobucks use multiple den-trees. However, they also occasionally den
in thick ground vegetation (Martin, 2006).
Due to logging, farming, and other human activities, the primary habitat of most populations
is now fragmented forest in agricultural land (Martin and Handasyde, 2007).
- Habitat Regions
- temperate
- terrestrial
- Terrestrial Biomes
- forest
- scrub forest
Physical Description
Mountain brushtail possums are medium-sized (2.6 to 4.2 kg) marsupials. They have
thick, light gray-brown fur, and long, dark gray, bushy tails. They differ morphologically
from their close relatives, short-eared possums (
Trichosurus caninus
), which is found directly to the north of mountain brushtail possums. No sexual dimorphism
is apparent (Lindenmayer, Dubach, and Viggers, 2002).
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Reproduction
Mountain brushtail possums appear to be socially monogamous. Adults are strongly paired
and remain very close to each other, staying in the same den on approximately 70%
of the days during mating season. Females form a pair-bond at 2 to 5 years of age
and the bonds only end at the death of one pair member. However, genetic evidence
suggests that mountain brushtail possums are not monogamous; molecular paternity analysis
has shown that 35% of young result from extra-pair copulations. Males that sired more
than one offspring a year, outside of the pair bond, are generally larger, indicating
that dominance results in reproductive success.
Mountain brushtail possums have a short, synchronous breeding season. Females have
one young per year. Young are in the pouch for approximately 6 months, and then spends
1 to 2 months riding on its mother’s back. Males play almost no part in raising the
young (Martin, Handasyde, Taylor, and Coulson, 2007).
- Mating System
- monogamous
- polygynous
Mountain brushtail possums breed once yearly, in January and February. Offspring remain
in the pouch for approximately 6 months and then ride on their mother’s back for another
1 to 2 months. Offspring are usually weaned around September. Juveniles remain close
to their mothers until they are approximately 18 months old. Females become sexually
mature between 2 and 5 years of age; males between 2 and 3 years (Martin, Handasyde,
Taylor, and Coulson, 2007).
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
Most mountain brushtail possum females give birth to one baby a year. The offspring
spend approximately 6 months in the pouch, then 1 to 2 months riding on the mother’s
back. Males spend the least amount of time with their female partners when the females
are carrying young on their back, and are therefore much less involved in the care
of offspring. Juveniles remain with their mothers until they are approximately 18
months old.
- Parental Investment
- female parental care
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-independence
-
protecting
- female
-
protecting
- post-independence association with parents
- extended period of juvenile learning
Lifespan/Longevity
Both male and female mountain brushtail possums appear to be long-lived, reaching
at least 12 years of age. However, it appears as though fewer males reach that age
than females (Martin and Handasyde, 2007). They are perhaps the longest lived marsupial
(Viggers and Lindenmayer, 2002).
Behavior
Mountain brushtail possums are nocturnal, staying in dens during the day and leaving
at night to forage. They are sedentary, often remaining in the same small home range
for their entire lives. Adults form strong pair-bonds and often share the same suite
of different dens with their offspring. The home ranges of paired individuals overlap
as well, as opposed to non-paired individuals, who remain more exclusive in their
home ranges.
Home Range
Both male and female adult mountain brushtail possums have a mean home range size
of 6.0 hectares, plus or minus 0.4 hectares. The home ranges of subadults are significantly
smaller. However, this data was gathered in a forest setting. Therefore, the home
ranges of those populations living in scrub settings is unstudied and unknown (Martin,
2006).
Communication and Perception
Like other possums,
Trichosurus cunninghami
relies on sight, hearing, touch, smell, and taste. Its whiskers enhance it's perception.
- Other Communication Modes
- scent marks
Food Habits
Mountain brushtail possums are herbivorous and frugivorous. They mainly eat
acacia
leaves, fungi, lichens, buds, fruit, and sometimes bark. Acacia is an integral part
of their seasonal diet, with different species of the plant consumed at different
times of the year.
- Plant Foods
- leaves
- wood, bark, or stems
- fruit
- bryophytes
- lichens
- Other Foods
- fungus
Predation
Mountain brushtail possum predators have not been well-reported. They are preyed on
by non-native foxes (
Vulpes vulpes
) and may also be taken by large snakes or raptors. The main threat to populations
is human action – the clearance of land for forestry and agriculture.
Ecosystem Roles
Mountain brushtail possums may influence vegetation community structure through their
herbivory. Allergic reactions to ectoparasites on the skin may be one of the main
causes of the disease 'rumpwear' in mountain brushtail possums (Hufschmid, Handasyde,
and Beveridge, 2010).
Economic Importance for Humans: Positive
Trichosurus cunninghami does not appear to be of positive economic importance to humans.
Economic Importance for Humans: Negative
Mountain brushtail possums are sometimes described as a destructive pest in southeastern
Australian pine plantations (IUCN Red List).
- Negative Impacts
- crop pest
Conservation Status
The conservation status of
Trichosurus cunninghami
is of least concern, according to the IUCN, and populations are considered stable.
Other Comments
Trichosurus cunninghami
was not described as a separate species from
Trichosurus caninus
until 2002.
Additional Links
Contributors
Helen McCreary (author), Yale University, Eric Sargis (editor), Yale University, Rachel Racicot (editor), Yale University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
- Australian
-
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- terrestrial
-
Living on the ground.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- scrub forest
-
scrub forests develop in areas that experience dry seasons.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- monogamous
-
Having one mate at a time.
- polygynous
-
having more than one female as a mate at one time
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- female parental care
-
parental care is carried out by females
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- social
-
associates with others of its species; forms social groups.
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- scent marks
-
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- herbivore
-
An animal that eats mainly plants or parts of plants.
- folivore
-
an animal that mainly eats leaves.
References
Hufschmid, J., K. Handasyde, I. Beveridge. 2010. The role of host and environmental factors in the epidemiology of rumpwear in brushtail possums. Australian Journal of Zoology , 58: 250-262. Accessed May 09, 2012 at http://www.publish.csiro.au/?act=view_file&file_id=ZO10030.pdf .
Irlbeck, N., I. Hume. 2003. The role of Acacia in the diets of Australian marsupials – a review. Australian Mammalogy , 25: 121-134.
Lindenmayer, D., J. Dubach, K. Viggers. 2002. Geographic dimorphism in the mountain brushtail possum T. caninus: the case for a new species. Australian Journal of Zoology , 50: 369-393.
Martin, J., K. Handasyde, A. Taylor, G. Coulson. 2007. Long-term pair-bonds without mating fidelity in a mammal. Behaviour , 144: 1419-1445.
Martin, J., K. Handasyde. 2007. Comparison of Bobuck demography in two habitat types in the Strathbogie Ranges, Australia. Journal of Zoology , 271: 375-385.
Martin, J. 2006. Den-use and home-range characteristics of bobucks, Trichosurus cunninghami, resident in a forest patch. Australian Journal of Zoology , 54: 225-234.
Menkhorst, P., D. Taggart, M. Ellis, R. Martin. 2011. "The IUCN Red List of Threatened Species" (On-line). Accessed April 10, 2012 at http://www.iucnredlist.org/apps/redlist/details/136256/0 .
Viggers, K., D. Lindenmayer. 2002. The Other Brushtail Possum. Nature Australia , Spring 27: 46.