A species of wallaby not seen in the wild on the Australian mainland for more than 100 years has been translocated to a West Australian wildlife sanctuary.

The banded hare-wallaby, which once had a population stretching from the Victorian and South Australian border to the West Australian coast, was last seen in the wild on the Australian mainland in 1906.

Now, the Australian Wildlife Conservancy (AWC) has translocated 60 banded hare-wallabies to the 7,800-hectare Mt Gibson Wildlife Sanctuary.

The fenced-off enclosure near Dalwallinu, about 350 kilometres north-east of Perth, is the state's largest cat and fox-free zone.

Chief executive Atticus Fleming said the wallaby could only survive in predator-free areas because its size made it particularly vulnerable.

"It's in that really critical weight range which makes it especially vulnerable to these feral predators," he said.

"It's only 1.5 to 2kg fully grown. It's just the right size for a cat or a fox to kill and eat."

That predation has meant the species has lost roughly 99 per cent of its original range.

'Military-style' operation to protect population

Following the decimation of its population via feral cats and foxes, the remaining 5,500 animals have lived on the small nature reserves of Bernier and Dorre Islands off the coast of Shark Bay.

To transport the animals, field staff from the AWC and the Department of Biodiversity, Conservation and Attractions undertook a fortnight-long operation.

"The translocation was a complex, logistical, almost military-style operation," Mr Fleming said.

The process involved catching animals on both the islands, with staff based on a boat just offshore.

Each night teams would visit one of the islands to track the animals and select those that met age and health prerequisites for translocation.

AWC staff undertook an almost military-style operation to transport the wallabies. ( Supplied: Australian Wildlife Conservancy/Brad Leue )

In the morning the selected wallabies would be transferred to Shark Bay via helicopter, before being placed aboard a light plane and flown to the wildlife sanctuary on the mainland.

"You're dealing with a very rare animal, so you need to make sure you're getting everything right at every stage of the translocation," Mr Fleming said.

"In this instance, you've got islands that are remote, and you're needing to move animals in a short time frame a large distance to another remote location.

"When you put all those factors together, it was a big operation to plan and a big operation to execute."

Translocation an unprecedented success

Mr Fleming said with successful breeding and more translocations, the mid-west population could grow significantly.

"We expect that population to grow to around 3,000 over the next five to 10 years," he said.

"We're looking at a 50 per cent increase in the current wild population of this very threatened animal as a result of this translocation."

So far the 27 males and 33 females released into the sanctuary have adapted well to the new home, with daily monitoring revealing a survival rate of 98 per cent.

The fenced-off Mt Gibson Wildlife Sanctuary is the state's largest cat and fox-free zone. ( Supplied: Australian Wildlife Conservancy/Brad Leue )

"The animals have got radio collars which allow us to not only check that they're surviving and that they're healthy, but also to get a good idea of what habitat in this new home they're selecting and preferring," Mr Fleming said.

"We had one mortality in the first few days.

"It's always sad to lose any animal, but we're happy with the progress of the translocation. That survival rate is unheard of."

It is hoped the population at Mt Gibson sanctuary, which also houses other reintroduced species including bilbies, could eventually become self-sustaining and be used as a source to boost other populations across Australia.