The mountain pygmy possum (Burramys parvus), also simply known as the burramys,[2][3] is a small, mouse-sized (weighs 45 grams (1.6 oz)) 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 1,300 to 2,230 metres (4,270 to 7,320 ft).

[1] The mountain pygmy possum was first discovered in the fossil record in 1895 when a portion of the jaw and skull bones were found in the Wombeyan Caves in central New South Wales.

[6] Since that time, the mountain pygmy possum has been located in three isolated, genetically distinct populations in the alpine regions of southern Australia.

Females tend to reside at higher elevations of approximately 1,400–2,228 m (4,593–7,310 ft) near patches of block streams and other deep boulder formations.

[5] Male home ranges are largest during the breeding season, between November and December, when they migrate to female nesting sites, and decline thereafter.

This moth species (Agrotis infusa) migrates to the high alpine mountainous regions during the spring and summer months.

Burramys parvis species will supplement their diet with the mountain plum pine from the fruit-bearing conifer Podocarpus lawrencei as well as seeds from the snow beard-heaths Leucopogon spp.

In order to ensure adequate fat reserves, female mountain pygmy possums will synchronise reproduction for the spring months, when Bogong moths are abundant.

[11] Mountain pygmy possums then have an internal gestation period of 14–16 days after which the altricial young will enter the forward-facing pouch of the female.

[12] For this reason, male mountain pygmy possums generally suffer higher mortality than females as the boulder fields appear to offer some protection from predation.

[10] Both males and females rely heavily on Bogong moths as an energy-rich food and for the fattening period which occurs prior to hibernation.

[7] During the months of hibernation, Burramys parvus is noted to awaken from torpor for periods of two to three days at a time during which the animal will feed on cached food resources.

[10] During the breeding season in the spring and summer months, older, heavier mountain pygmy possums typically occupy the highest quality habitats.

The construction of ski resorts in the alpine regions in which the mountain pygmy possums inhabit has been one of the greatest factors attributed to population decline.

[5] Although data from New South Wales and Victoria are still pending, preliminary models suggest that reduced survival of mountain pygmy possums can be related to declining snow cover and shorter winters.

[5] As a suggested solution to this environmental disturbance, Broome and her colleagues proposed moving the remaining populations of mountain pygmy possums from their alpine habitats to lower elevation temperate rainforests.

This solution is based on previous husbandry efforts, which showed that mountain pygmy possums did not require a period of hibernation at environmental temperatures above 12 °C (54 °F).

These threat abatement plans identify the necessary actions required to protect all species affected by predation of red foxes and feral cats.

In addition, Bogong moths are rich in protein and fat and they provide mountain pygmy possums with the necessary energy reserves to sustain the seven-month hibernation period.

[5] The Foundation for National Parks & Wildlife has implemented captive breeding programmes under the support and guidance of Linda Broome and her colleagues.

[14] 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.

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.

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.

[21] 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.