One of Australia’s most endangered marsupials, a tiny mountain pygmy-possum (Burramys parvus) nibbles some peanut butter from a keeper’s finger. These possums are only found in three small regions in the wild, all within the Australian Alps: Mt Bogong and Mt Buller, Victoria, and Mt Townsend, NSW.

A sleepy koala (Phascolarctos cinereus) stretches out a leg, revealing a unique foot adapted to life in the trees. Koalas are beset with a complex problem, declining by about 45 per cent in Queensland over the last 10 years, but only by 7 in Victoria. Recent moves have seen them classified into two different groups, with northern koalas considered vulnerable.

Southern corroboree frogs (Pseudophryne corroboree) are small, but hard to miss, due to vivid yellow and black markings that stand out against the sphagnum moss of their habitat. You’ll be hard pressed to spot them in the wild, however, where they are critically endangered, with only about 100 thought to survive.

The young saltwater crocs (Crocodylus porosus) keep a watchful eye on anyone who enters the reptile enclosure.

Superb lyrebirds (Menura novaehollandiae) breed in the depth of winter, and are renowned for their mimicry. This particular bird switches between the call of a car alarm and two kookaburras.

The pygmy-possums (Burramys parvus) are housed in wooden nest boxes in a climate controlled room, allowing keepers to monitor this insurance population. This species is the only marsupial known to hibernate under the snow during the coldest months of the year.

Healesville Sanctuary keeper Peter Comber weighs a mountain pygmy-possum (Burramys parvus) as part of a routine health check.

Southern corroboree frogs (Pseudophryne corroboree) can’t hop like other frogs. Instead, they crawl around in the moss.

Dargo, one of the stars of Healesville Sanctuary, is a nine-week-old pure-bred alpine dingo pup (Canis lupus dingo). Dingoes can be classified, depending on their area of origin, as alpine dingoes, desert dingoes, northern dingoes, Cape York dingoes or tropical dingoes.

A she-oak skink (Cyclodomorphus casuarinae) peers out through grass. Alpine skinks are susceptible to local wildfires. It is Healesville’s aim to learn as much as possible about the species’ breeding biology, ensuring a recipe for captive breeding in case a large portion of the she-oak’s population is wiped out.

Mike Swan, a keeper at Healesville Sanctuary, is dedicated to the conservation of threatened native reptiles like the alpine she-oak skink (Cyclodomorphus casuarinae).

Alpine she-oak skinks (Cyclodomorphus casuarinae) are safe in the hands of Healesville Sanctuary keeper and reptile field guide author, Mike Swan.

Dargo the dingo pup (Canis lupus dingo) regularly wanders the grounds of Healesville Sanctuary under the watchful gaze of his keepers.

Healesville Sanctuary keeper Mason Hill weighs a corroboree frog. Gloves are essential to prevent the transmission of harmful pathogens to the frogs. Chytrid virus, a deadly skin disease, for example, has become a world-wide problem, killing off many species of frog.