Mountain pygmy-possum: our precious possum in the snow

Name: Mountain pygmy-possum (Burramys parvus), also known as burramys

Group: Possums

Size: Body length 11cm, tail length 15cm; weight 35g (post-hibernation) – 80g (pre-hibernation)

Diet: Invertebrates including the endangered Bogong Moth, native fruits and seeds.

Habitat: Restricted to only three small locations on Australia’s highest peaks of the alpine zone.

Conservation status: Critically Endangered.

Superpower: Super snoozers! These possums hibernate for 5-7 months every year under the snow! They are also Australia’s most impressive yo-yo dieters, losing half their weight and gaining it back again every year.

The mountain pygmy-possum is a truly unique Aussie battler. It has amazingly soft fur, big bright eyes, an adorable whisker-fringed pink nose, tiny but dextrous little pink hands, and a long tail it can curl into a tight spiral.

The mountain pygmy-possum is Australia’s only mammal found exclusively in the alpine zone – on Mt Kosciusko in NSW, and on Mt Buller and the Bogong High Plains in Victoria. The possums hibernate for 5-7 months under the snow each year, slowing their breathing and heart rates, dropping their body temperatures to 2-3°C, and their metabolism by 98%. They curl their tails and tuck their noses into their pouch (females) or under their heart-shaped scrotum (males) to keep warm, resembling tiny, fluffy possum balls. During their hibernation, they can lose half their body weight, but between spring and autumn they double it again.

After hibernation, the tiny possums wake from their big sleep, hungry for their favourite foods – and for love. Males make their way from lower down the mountains to the highest peaks where females await in their spring time boulder-field boudoirs. And boy, do they make up for lost time: both males and females choose multiple partners, largely based on scent and genetic dissimilarity. Females have a short pregnancy of around 13 days and give birth to up to four tiny young, each resembling a pink jellybean. As females mate with more than one male, they can give birth to litters with mixed paternity. Tiny possum babies born at the same time may have different fathers! It’s a very clever way to increase the genetic diversity of your litter. In late summer and autumn, the possums fill up on invertebrates, fruits and seeds to prepare for their icy winters. Females stay in the best and highest habitat, while males travel back down the mountain to sleep and dream of their next journey of love.

The mountain pygmy-possum is a “Lazarus” species. It was only known from the fossil record until it was rediscovered alive in a Mt Hotham ski chalet in 1966. Sadly, by this time, introduced cats and foxes roamed its habitat, fires had raged, and historic habitat destruction had taken its toll. Climate change is further threatening the survival of this possum in the snow. The mountain pygmy-possum is critically endangered with likely fewer than 2,000 possums left. Thankfully, passionate possum protectors and a mountain pygmy-possum recovery team are helping, monitoring the possums, controlling predators, running captive breeding and research programs, revegetating habitat, and building new tunnels of love to help males and females meet and mate. Following the recent collapse of the migratory Bogong moth (a key mountain pygmy-possum food source, recently added to the IUCN endangered list), possum professionals swung into action again, increasing monitoring, developing a supplementary food called Bogong Bikkies, asking the public to log any Bogong moth sightings through Moth Tracker, and to turn their Lights off for the Bogong moth.

This tiny Aussie icon is amazing, and one we should all be proud of.

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