Mammals

The species varies its diet according to the season. During the summer it feeds primarily on high-energy food such as the Bogong moth (Agrotis infusa), which migrates yearly to the Australian Alps for breeding. At this time the diet is supplemented with other arthropods such as caterpillars, millipedes, beetles and spiders. As winter approaches the abundance of arthropods decreases, and the pygmy possum switches its diet to seeds and berries. Living at high altitude, the species hibernates under a blanket of snow during the winter months (May to September). During this time the animals live off fat reserves built up during the ‘active period’ and will occasionally come out of torpor to feed on stored seeds and berries (it is the only marsupial to store food in a cache).

Unlike most possums, the mountain pygmy possum is not arboreal, although it is well adapted for climbing shrubs. The species is nocturnal – spending the day curled up in a ball to retain heat – and social, with females occupying communal nesting sites and overlapping home ranges. Males are more nomadic and generally only come into contact with the females to breed. Breeding takes place at the start of the ‘active season’ when there is plenty of high energy food about. Females give birth to four young which develop in the pouch for a few weeks before transferring to a nest constructed of grasses. Although the young become independent at 9 weeks the female will not have a second litter due to the need to store fat reserves for hibernation. Mountain pygmy possums are extremely long-lived for their size, and females can survive for up to 12 years in the wild.

The species lives in amongst rock screes and boulderfields in the alpine and sub-alpine zones of the ‘Australian Alps’. It is found at altitudes of 1,500-1,800 m, where the climate is cold and wet, with frequent snow-falls and powerful winds. The characteristic vegetation of these mountain peaks is a heathland of Mountain Plum Pine (Podocarpus lawrencei) and associated alpine grasses and shrubs.

The population is estimated to be less than 2,000.

Classified as Critically Endangered B1ab(iii,v)+2ab(iii,v) on the 2010 IUCN Red List of Threatened Species.

The species’ habitat is highly restricted and is being destroyed or fragmented by rock extraction for dam/aqueduct construction and the development of infrastructure for the downhill skiing industry. Snow-grooming operations can destroy vegetation when snow cover is thin and may disturb the animals when they are hibernating. Buildings and roads act as barriers to the dispersal of males as well as reducing the amount of available habitat. Other causes of habitat degradation include the invasion of weeds such as English broom and blackberries. The species is predated by introduced animals such as foxes and cats, although it is unclear what effect this is having on populations. Continued long-term declines in populations are predicted as temperatures rise and snow cover decreases due to global warming.

The species occurs in Bogong National Park (Victoria) and Kosciusko National Park (NSW). A government-endorsed management plan exists in Victoria and a recovery plan has been launched in NSW. Conservation actions have aimed primarily at protecting existing populations by strictly controlling development in protected areas. Where the species occurs in established ski resorts, underground tunnels have been constructed to aid in dispersal between intact habitat and ski resort habitat. Important populations are monitored regularly and research is being conducted into the distribution of the Mt. Buller population. A captive colony has been established at Healesville Sanctuary.

Proposed conservation actions include monitoring the effects of snow grooming on the species and the loss of snow cover on hibernation and winter survival. Population and habitat monitoring should continue and populations of feral predators and exotic species should be controlled. Reports of the possible occurrence of mountain pygmy possums in the Cobberas - Tingaringy region in eastern Victoria should be investigated and any further populations should receive immediate protection. Public awareness programmes will help to highlight the plight of this small animal.

Action Plan for Australian Marsupials and Monotremes
Victoria Department of Natural Resources and Environment NSW National Parks and Wildlife Service, Healesville Sanctuary, Alpine Resorts Commission (Victoria)

Maxwell, S., Burbidge, A. A., Morris, K. and the IUCN/SSC Australasian Marsupial and Monotreme Specialist Group (eds.). 1996. The 1996 Action Plan for Australian Marsupials and Monotremes. Wildlife Australia, Endangered Species Programme.

Menkhorst, P., Broome, L. & Driessen, M. 2008. Burramys parvus.In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. Downloaded on 12 November 2010.

Nowak, R.M. 1999. Walker's Mammals of the World. Sixth edition. The Johns Hopkins University Press, Baltimore and London.

NSW National Parks and Wildlife Service. 2002. Approved Recovery Plan for the Mountain Pygmy-possum, Burramys parvus. NSW National Parks and Wildlife Service, Hurstville, NSW.

Distribution map based on data provided by the IUCN Global Mammal Assessment.