The mountain pygmy possum was discovered as a fossil by Robert Broome in 1894. He named the species Burramys parvus, meaning small rock mouse, although it is not a mouse at all (Broome and Mansergh 1994). Dentition studies revealed a plagiaulacoid premolar, like that characteristic of the family Potoroidae. From this observation, it was questioned whether the pygmy possum was actually a tiny kangaroo (Ride 1970). For seventy years, B. parvus was considered a fossil, until again found in a Victorian alps ski lodge in 1966 by accident (Ride 1970). Another interesting aspect of B. parvus life history is hibernation. Burramys parvus hibernates in the cold alps winter. It puts on large amounts of fat, which serves as energy during the reduced metabolic and body temperature state of torpor. During torpor, B. parvus rolls itself into a ball and tucks its tail around the body. Although energetically costly to rewarm the body, B. parvus occasionally arises during hibernation to feed on the seeds cached in its burrow (Broome and Mansergh 1994). The hibernation period lasts for 6 months, from February through July.
Perception Channels: tactile ; chemical
The Mountain Pygmy Possum lives in the Australian alps, where the ski industry has been growing since the mid 1950's. Leveling and grooming of land for ski trails has greatly affected the amount of available habitat for B. parvus. While B. parvus oftens makes its home in ski lodge foundations, the dispersal of males to and from the natal site has become increasingly difficult. Also problematic is the destruction of trees and shrubs, which B. parvus uses for food. Sufficient field data were collected in 1979 by Ken Norris, an Australian zoologist, and his associates to place a threatened label on B. parvus. A debate between tourism economists and wildlife conservationists soon developed (Broome and Mansergh 1994). Since these debates, measures have been taken to decrease the amount of habitat fragmentation and destruction by the ski industry. For the B. parvus habitats in established ski resorts, underground tunnels with simulated B. parvus habitat substrate have been constructed to aid in dispersal between intact habitat and ski resort habitat (Mansergh and Scotts 1992). These tunnels have become respected at the ski resorts by tourists and government officials alike. Future management plans to save B. parvus include protecting undestroyed lands and buffer lands surrounding the ski areas, continuing to devise tunneling systems for already affected B. parvus populations, monitoring effects of snow grooming on B. parvus habitats and populations, and making the public more aware of the vulnerability of this animal (Broome and Mansergh 1994).
The present habitat of B. parvus is less than 10 square kilometers. The present population of B. parvus is no more than 2600 adults (Strahan 1995).
IUCN Red List of Threatened Species: critically endangered
Ski industries sometimes feel their land acquistion opportunities are being thwarted by efforts aimed at conservation of B. parvus habitats. Recent conservation efforts (tunnel building) for B. parvus have been tolerated and accepted by established ski resorts. However, it has become increasingly difficult for new entrepeneurs in the industry to find unprotected portions of B. parvus habitat to develop.
Conservationists consider Burramys parvus economically important to research. The confined habitat and home ranges of B. parvus make it ideal for studies on wildlife managment, especially those with rapidly declining population. By establishing broad range methods to effectively treat animal populations, less monetary funds will be required for species specific method development.
The mountain pygmy possum is best described as an omnivore-insectivore-granivore- frugivore. While eating habits of B. parvus are diverse, the diversity of prey is low, making B. parvus a specialized feeder, according to the season. During the 'active season' from October-April, B. parvus' diet contains high energy food. During this period, B. parvus is an omnivore and insectivore, feeding heavily upon the Bogong moth (Agrotis infusa), which migrates yearly to the Australian alps for breeding. The yearly migration of the moth provides a predictable, energy rich and abundant food supply for B. parvus. Studies conducted by Mansergh and associates (1990) reveal that the Bogong moth constitutes over 33% of the total 'active season' diet of B. parvus. A later study by Smith and associates (1992) reported that the moth may actually be the only dietary item during the reproductive season (October-December) of B. parvus. It has been found that females take a higher percentage of Bogong moths than males, due to the concurrent breeding season and additional nutritional supplements required to raise offspring (Smith and Broome 1992). Other insects, consumed in sparse quantities, are caterpillars, millipedes, beetles and spiders (Broome and Mansergh 1994). As the active season progresses, the abundance of Bogong moths decreases, leading to a dietary switch from moths to seeds and berries. The mountain pygmy possum prefers the seeds of habitat specific species such as Mountain Plum-pine, Rambling Bramble, and Snow Beard-heath, during the months of January-April (Broome and Mansergh 1994).
During the 'non-active', or hibernation season, B. parvus caches seeds and berries, which constitute over 75% of their diet from May-October (Broome and Mansergh 1994). The mountain pygmy possum is the only marsupial found to cache non-perishable food items (Menkhorst 1995).
Burramys parvus is well adapted to its specialized diet. The mountain pygmy possum has agile forelimbs that permit manipulation of seeds, berries and insects. The hard coats of seeds and insect exoskeletons are easily opened with a plagiaulacoid premolar. Burramys parvus uses its procumbent lower incisors to scoop out the interior of the seed or insect.
The mountain pygmy possum, Burramys parvus, lives in the alps of Victoria and New South Wales, Australia. More specifically, it is found atop the Mount Bogong, Mount Loch and Mount Higginbotham mountain ranges of Victoria. In New South Wales, it is found predominantly in the mountain ranges of Kosciusko National Park, which include Mount Townsend, Mount Kosciusko, and Mount Blue Cow (Broome and Mansergh 1994). Burramys parvus ranges in elevation from 1400m to 2230m (Strahan 1995).
Biogeographic Regions: australian (Native )
Burramys parvus lives in a cold, wet climate. Snow is possible year round, but is most frequent between June and September. When snow is not blanketing the ground, rain and powerful winds are typical. The New South Wales and Victorian alps annual rainfall is greater than 1500mm. The altitude of the alps causes temperatures to be low, seldom exceeding 10 degrees celsius from May to September (Broome and Mansergh 1994). The habitat of this species can be described as a boulderfield. Recurrent wetting and freezing of water on the rock surfaceshas led to fragmentation of boulders. These fragments provide necessary protection from the harsh climatic conditions and alpine predators. Burramys parvus often has been found nesting among the crevices. Plants establish in shallow fragments, providing the mountain pygmy possum with plentiful resources (Strahan 1995). These plants are typically low shrubs with grasses intermixed (Strahan 1983).
Terrestrial Biomes: tundra ; mountains
Average lifespan
Status: wild: 4.0 years.
Average lifespan
Status: captivity: 7.0 years.
Burramys parvus is a small, rodentlike marsupial. Both sexes are about 110mm in head and body length, with males being slightly longer and heavier than females. The tail of B. parvus is prehensile, ranging from 140mm in females to 148mm in males (Strahan 1983). The fur is fine, but dense. The dorsal side is grey, with a darker section at the back and head midline. The ventral surface is light cream, with males developing a bright fawn-orange in breeding season. The forepaws are dexterous, easily able to manipulate food, while on the hindfoot the hallux aids in climbing (Broome and Mansergh 1994).
Other Physical Features: endothermic ; bilateral symmetry
Average mass: 45 g.
Average basal metabolic rate: 0.205 W.
Burramys parvus follows a low fecundity, high longevity life strategy. The mountain pygmy possum has a non-breeding season from January-April, when it gain sweight for the coming winter and the young disperse. The inactive season, from May-September, is hibernation season for B. parvus. From September through December, B. parvus is in an active season of breeding. B. parvus females are polyestrous but limited to one litter per year by the need to store fat reserves for hibernation. Without sufficient fat, the females die. In response to fat reserve limitations, B. parvus synchronizes its reproduction with spring, when nutrient rich Bogong moths are abundant. Breeding occurs annually for many consecutive years. Reproducing females have been found up to 12 years of age, which makes them one of the longest lived small terrestrial mammals.
Studies have successfully mapped out the reproductive timeline of the mountain pygmy possum (Mansergh and Scotts 1990). Mating occurs between late September and mid October. Female estrous lasts ~20 days. After fertilization, a gestation period of 13-16 days ensues, followed by birth in the last week of October of four altricial young (Mansergh and Scotts 1990). The young have well developed forelimbs and heads for traveling from the cloaca to the pouch. The female cleans a trail for the young to the pouch, where the young attach to a teat (Broome and Mansergh 1994). Frequently the female bear smore than four young, leading to more offspring than teats. Under these circumstances, the 'slowest' young will not have a teat when it arrives in the pouch, and will die. The lactation period lasts 30 days, with a subsequent nesting period of 30-35 days (Strahan 1995). The young are fully weaned and independent after 65 days. Young disperse between January and March (Lee and Cockburn 1985). At approximately 1 year of age, the young begin mating. Only 50% of the reproducing young will survive, due to the inability of younger B. parvus to maintain fat reserves for hibernation (Mansergh et al. 1990). By their second summer, young are fully capable of sustaining themselves for both activities (Strahan 1995).
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average gestation period: 15 days.
Average number of offspring: 3.5.
Average age at sexual or reproductive maturity (male)
Sex: male: 320 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 320 days.
