Trichosurus cunninghamimountain brushtail possum

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Geographic Range

Mountain brushtail possums, or southern bobucks, are native to southeastern Australia, ranging from Victoria to Central Queensland. (Lindenmayer, et al., 2002)

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). (Lindenmayer, et al., 2002; Martin and Handasyde, 2007; Martin, 2006)

  • Range elevation
    0 to 1300 m
    0.00 to 4265.09 ft
  • Average elevation
    300-1300 m
    ft

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). (Lindenmayer, et al., 2002)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    2.5 to 4.5 kg
    5.51 to 9.91 lb
  • Range length
    81 to 93 cm
    31.89 to 36.61 in

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). (Martin, et al., 2007)

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). (Martin, et al., 2007)

  • Breeding interval
    Mountain brushtail possums breed once yearly.
  • Breeding season
    The breeding season is January to February.
  • Range number of offspring
    0 to 1
  • Average number of offspring
    1
  • Range gestation period
    15 to 17 days
  • Range weaning age
    5 to 6 months
  • Range time to independence
    17 to 18 months
  • Range age at sexual or reproductive maturity (female)
    2 to 5 years
  • Range age at sexual or reproductive maturity (male)
    2 to 3 years
  • Average age at sexual or reproductive maturity (male)
    3 years

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. (Martin, et al., 2007)

  • Parental Investment
  • female parental care
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • protecting
      • female
  • 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). (Martin and Handasyde, 2007; Viggers and Lindenmayer, 2002)

  • Range lifespan
    Status: wild
    12 (high) years

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. (Martin, et al., 2007)

  • Range territory size
    0.056 to 0.064 km^2

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). (Martin, 2006)

Communication and Perception

Like other possums, Trichosurus cunninghami relies on sight, hearing, touch, smell, and taste. Its whiskers enhance it's perception. (Martin, 2006)

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. (Irlbeck and Hume, 2003)

  • 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. (Menkhorst, et al., 2011)

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). (Hufschmid, et al., 2010; Menkhorst, et al., 2011)

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). (Menkhorst, et al., 2011)

  • 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. (Menkhorst, et al., 2011)

Other Comments

Trichosurus cunninghami was not described as a separate species from Trichosurus caninus until 2002. (Viggers and Lindenmayer, 2002)

Contributors

Helen McCreary (author), Yale University, Eric Sargis (editor), Yale University, Rachel Racicot (editor), Yale University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

acoustic

uses sound to communicate

arboreal

Referring to an animal that lives in trees; tree-climbing.

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.

chemical

uses smells or other chemicals to communicate

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.

female parental care

parental care is carried out by females

folivore

an animal that mainly eats leaves.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

herbivore

An animal that eats mainly plants or parts of plants.

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).

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

polygynous

having more than one female as a mate at one time

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

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.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

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. 2006. Den-use and home-range characteristics of bobucks, Trichosurus cunninghami, resident in a forest patch. Australian Journal of Zoology, 54: 225-234.

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., K. Handasyde, A. Taylor, G. Coulson. 2007. Long-term pair-bonds without mating fidelity in a mammal. Behaviour, 144: 1419-1445.

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.