The mountain pygmy possum (Burramys parvus), also simply known as the burramys, is a small, mouse-sized (weighs ) nocturnal marsupial of Australia found in dense alpine rock screes and boulder fields, mainly southern Victoria and around Mount Kosciuszko in Kosciuszko National Park in New South Wales at elevations from . It is also the only Australian mammal restricted to alpine habitat. At the time, the species was believed to be extinct. It was not until 1966 that a living individual was found at a ski resort at Mount Hotham in Victoria. Since that time, the mountain pygmy possum has been located in three isolated, genetically distinct populations in the alpine regions of southern Australia. In addition, the mountain pygmy possum has a pouch which opens anteriorly and contains four teats. The mountain pygmy possum has a long prehensile tail, averaging about in length, which is sparsely haired.
Habitat and geographic range
The mountain pygmy possum is endemic to the alpine regions of southern Australia. The species is currently restricted to three isolated mountain regions: (1) Mount Blue Cow in Kosciuszko National Park in New South Wales, (2) Mount Bogong and Mount Higginbotham/Loch in the Bogong High Plains in Victoria, and (3) Mount Buller in Victoria. The typical home ranges within these mountain ranges differ for males and females. Females tend to reside at higher elevations of approximately near patches of block streams and other deep boulder formations. The home range of a female mountain pygmy possum is correlated with the density of bogong moths, the pygmy possum's preferred food source, which varies at different elevations. Females at higher elevations have smaller home ranges due to a relatively greater abundance of bogong moths, whereas females residing at lower elevations typically have much larger home ranges as the quantity of moths declines. Male mountain pygmy possums reside at low elevations, generally between , of these mountain ranges. Upon finding food, the mountain pygmy possum will first smell the food source before picking it up with its incisors. It will then transfer the item to its forelimbs so that it may manipulate the food and tear off pieces of flesh. For this reason, male mountain pygmy possums generally suffer higher mortality than females as the boulder fields appear to offer some protection from predation. Individuals in torpid periods will curl their bodies up, tucking their heads into their chest or abdomen in order to retain body heat. In addition, females have been observed sharing nests constructed from moss and snow grass.
Climate change is another serious threat to the mountain pygmy possum. Burramys parvus is the only Australian mammal which is completely restricted to the alpine regions. The species is well adapted to the seasonal availability of bogong moths and other food resources. In addition, Zoos Victoria has also become involved in the effort to sustain the remaining populations of mountain pygmy possums. Zoos Victoria started a captive breeding programme for B. parvus in 2007 in the Healesville Sanctuary. The programme cared for a population of 45 mountain pygmy possums. Their overall goal is to down-list the mountain pygmy possum to a lower-threat category on the IUCN Redlist.
there is a new captive breeding project under way in Lithgow, New South Wales, called Secret Creek Sanctuary. The creation of the sanctuary has been aided by a donation of from Prague Zoo, which had set up a fund-raiser during the 2019–20 bushfires in Australia. The Australian Wildlife Society also contributed much-needed funds to help save this species from the risk of extinction. About 15 animals will be live-captured from Mt Kosciusko, acclimatised in special enclosures, and released then into the sanctuary.
2016 National Recovery Plan
In 2016 the first national recovery plan (under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999) for this species was prepared, to counter the threats caused by habitat loss and fragmentation, predators (cats and foxes) and climate change, in particular to the tiny Mt Buller population. The plan detailed its distribution, habitat, threats, recovery objectives and actions necessary to ensure its long-term survival.
2018–19: decline in bogong moths
Scientists observed a catastrophic drop in bogong moth numbers in the summer of 2018–2019, due to climate-change-induced droughts in the moth's breeding areas. With the lack of moths as a food source during the breeding season in the spring of 2018, the possums lost litters owing to inadequate nourishment. As a similar situation occurred in the spring of 2017, adult possum numbers were predicted to decline as well.
In the spring and summer seasons of 2017–18 and 2018–19, dramatic drops in numbers of the moths in the Alpine caves were observed. Millions of the moths typically line the walls of these caves over summer, but in 2017–2018, some had none. Eric Warrant of Lund University attributed the falling numbers to winter drought in their breeding areas and climate change, the lack of rain producing insufficient vegetation to feed the caterpillars.
Other biologists and ecologists have pointed to the dramatic effect on the animals which feed on the moths, which are an important source of protein for wildlife, including the mountain pygmy possum as well as other insectivorous mammals and birds. "The vulnerability of the Australian Alps to climate change is the worst in the world because we've got these short little mountains so when it gets warmer, there is nowhere for these cold-adapted species to go", according to Deakin University wildlife ecologist Euan Ritchie.