Mammals

Mountain Pygmy Possum

Burramys parvus · also called burramys

Critically Endangered ↓ omnivore Mountains

The mountain pygmy possum was described as a fossil in 1896 and assumed to be long extinct. Then in 1966 a live one walked into a ski lodge. It turned out to be a mouse-sized alpine marsupial that does something no other marsupial does: it hibernates through the winter under the snow.

Overview

Burramys parvus lives only in the alpine boulder fields of the Australian Alps, above about 1,400 m, in a total range of around 10 square kilometres across three isolated mountain areas. It eats Bogong moths in the warm months and caches seeds and fruit for winter.

The only hibernating marsupial

It spends up to seven months under the winter snow, its body cooling close to freezing and its metabolism almost stopping. A deep, stable snowpack insulates its boulder den and is essential to survival, which makes a warming climate a direct threat.

Tied to a moth

Each spring it emerges to breed just as billions of Bogong moths arrive in the mountains. When drought collapsed the moth migration in 2017 and 2018, possums starved, and the moth is now listed as endangered too.

Status

Critically Endangered, fewer than about 2,000 adults in three fragmented populations, threatened by shrinking snow, the moth’s collapse, resort development, and feral predators. Road tunnels — one called the “tunnel of love” — have been built to reconnect the possums.

Mountain Pygmy Possum: common questions

How was an animal named from fossils before anyone had seen a live one?

In 1894 a palaeontologist described a small possum jaw from Pleistocene cave deposits in New South Wales and, in 1896, gave the animal the name Burramys parvus, assuming it was one of many marsupials that had died out since the last ice age. For 70 years it was known only from such bones. Then in August 1966 a naturalist staying at a ski club lodge on Mount Hotham, in the Victorian Alps, caught a live small possum in the building and recognised it as the supposedly extinct Burramys. It is one of the clearest examples of a so-called Lazarus taxon, a species presumed extinct that is later found alive.

Why is the mountain pygmy possum the only marsupial that hibernates?

Most marsupials live in climates where food is available year-round or where they can use short daily torpor to save energy, so none of them evolved a long seasonal shutdown. The mountain pygmy possum is the exception because it lives where almost nothing else does, on high Australian mountains that are buried in snow for months, with no accessible food. Its answer is to fatten up in autumn on cached seeds and fruit, retreat into a nest deep in a boulder field, and hibernate for up to seven months, letting its body cool to near freezing so it burns almost no energy. The insulating snowpack over the boulders is essential to this, which is why the possum is so exposed to climate change.

What do Bogong moths have to do with it?

Everything, in the breeding season. Each spring, billions of Bogong moths migrate from the lowland plains to the Australian Alps to spend the summer sheltering in cool rock crevices, and for the mountain pygmy possum, which emerges from hibernation hungry and about to breed, these fat-rich moths are the single most important food. In 2017 and 2018, drought on the breeding grounds caused the Bogong moth migration to collapse to a tiny fraction of normal, and mountain pygmy possums in some areas starved, with females unable to raise young. The moth has since been listed as endangered itself, and its fate and the possum's are now tied together.

What is being done to save it?

A lot, given how few animals there are. Conservation work includes supplementary feeding of Bogong-moth substitute during poor moth years, control of feral cats and foxes, restoration and protection of boulder-field habitat, and the construction of rock-lined tunnels under roads and ski runs, one nicknamed the tunnel of love, to let males reach female habitat to breed. A captive-breeding programme maintains an insurance population, and there is a long-term proposal to establish a population at lower, cooler-forest sites where the species lived during past warm periods, as a refuge from alpine warming.

Sources & further reading

Written by HideShark Editorial Team · reviewed by HideShark Science Desk. Published October 10, 2026. Last updated October 10, 2026.

Quick facts

Scientific name: Burramys parvus
Diet: Bogong moths in spring and summer, which arrive in the mountains in huge migrating swarms and are the animal's key high-energy food, plus seeds, berries, and other fruit that it caches for winter, and some other insects
Described as a fossil first: The species was named in 1896 from ice-age bones found in a cave, and it was assumed to be extinct until 1966, when a live one turned up in a ski lodge at Mount Hotham, making it a rare case of an animal known as a fossil before it was known alive
The only hibernating marsupial: It is the only Australian marsupial that enters true deep hibernation, spending up to seven months under the winter snow in a nest among boulder fields, its body temperature dropping close to freezing and its metabolism nearly shutting down, roused only briefly every few weeks
It needs the snow: A deep, stable snowpack insulates the boulder dens and keeps them at a steady temperature just above freezing through winter; a thin or patchy snow year exposes the possums to hard frosts and to predators, so a warming climate that reduces alpine snow is a direct threat
A tiny total range: The entire species lives in about 10 square kilometres of boulder field, spread across three isolated mountain areas in the Australian Alps of Victoria and New South Wales, at elevations above roughly 1,400 m
Females hold the high ground: Females occupy the best boulder-field habitat and males live lower down, travelling up to breed in spring; road and resort development has cut some of these routes, and tunnels called the tunnel of love have been built to reconnect populations
A long life for its size: Despite being no bigger than a large mouse, a mountain pygmy possum can live up to about 12 years in the wild, far longer than a placental mammal of the same size, linked to its slow, hibernating lifestyle
Range: The alpine and subalpine boulder fields of the Australian Alps, restricted to Mount Higginbotham to Mount Loch, the Bogong High Plains, and Mount Buller in Victoria, and the Mount Kosciuszko area of New South Wales, above about 1,400 m.
Conservation status: Critically Endangered ↓ ≈ Fewer than about 2,000 adults, in three fragmented alpine populations, listed as Critically Endangered; threatened by declining and less reliable alpine snow cover, the collapse of Bogong moth numbers during drought years, habitat loss and fragmentation from ski resorts and roads, predation by feral cats and foxes, and its own tiny, isolated populations in the wild