A feral predator-free zone in Western Australia could become home to the largest population of a mysterious marsupial with an unusually chivalrous mating system.

The red-tailed phascogale is a small, carnivorous animal weighing less than a deck of cards and is largely unknown to the public, unlike its famous relative the Tasmanian devil.

According to ecologist Laura Ruykys from the Australian Wildlife Conservancy (AWC), that anonymity stems from the creature's shy behaviour.

"They're cryptic and small in size and nocturnal," she said.

"They are charismatic but they're not as big and charismatic as say, the Tasmanian Devil."

Dr Ruykys said despite being "quite the fearsome predator" the tiny creatures are also preyed upon by feral animals, such as cats.

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

Once found across almost half the continent, the marsupial's population has contracted to isolated pockets in south-western Australia, and it is estimated there are fewer than 10,000 adult red-tailed phascogales left in the wild.

To try to boost the threatened species' population, 19 of the animals have been taken from populations in Western Australia's south-west and driven 300 kilometres north to the Mt Gibson Wildlife Sanctuary.

The fenced off enclosure is the state's largest feral cat-free zone.

Dr Ruykys said with successful breeding and more translocations, the Mid West population could eventually grow to about 1,300.

"Obviously that'll substantially improve the conservation prospects for this species longer term," she said.

Males die after hours-long mating session

Dr Ruykys said the animals had a unique and intriguing courtship system.

During their mating seasons, male red-tailed phascogales delve into their energy stores as they wander up to 80 hectares in the search for females.

The tiny predatory marsupial weighs less than a deck of cards. ( Supplied: Australian Wildlife Conservancy )

After mating, which can take up to six hours, the males die from organ failure or infection.

"It is quite a chivalrous mating system in some ways, because it actually allows larger clutch sizes because the males have put all of their energy into their reproduction," Dr Ruykys said.

"It also potentially liberates the food resources for the female and her fairly large number of offspring, so that they can capitalise on food resources during what might otherwise be a fairly lean time for her."

Although females can live for up to three years, they often die after their first clutch is weaned.

"So the entire population is reliant on the survival of each year's crop of offspring," Dr Ruykys said.

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.