In short:

Around 20 female northern quolls with young are being moved into a 950-hectare refuge near Townsville.

Once abundant in parts of Australia, northern quoll numbers are dwindling.

What's next?

It is hoped the quolls will den with their young and begin breeding to boost the population.

A team of ecologists is capturing and relocating female northern quolls to a north Queensland safe haven to create an insurance population as numbers of the endangered marsupial dwindle.

Once abundant across Queensland, the Northern Territory and Western Australia, the northern quoll is struggling.

John Kanowski, chief science officer with the Australian Wildlife Conservancy, said the species had "collapsed from most of its range" due to feral cats and wildlife.

"We've caused so much damage to the environment in the last 150 years," he said.

"The loss of these small to medium sized mammals is a thing that's happened right across the continent."

A predator itself, the northern quoll also has a taste for invasive cane toads, which produce a poison that can be deadly.

In a bid to build up the population, the Australian Wildlife Conservancy is translocating northern quolls to a 950-hectare fenced haven on its property near Paluma, north of Townsville.

Mr Kanowski said there are historic accounts of an abundance of the animal in the area.

"If this reintroduction is successful, it will be the only population of the northern quoll on the mainland where there's no feral cats," he said.

Mr Kanowski said when feral cats are present, population density is low, making the quolls vulnerable to other threats.

Females prioritised

Senior field ecologist Felicity L'Hotellier said female northern quolls with young are being targeted for relocation to help boost numbers.

She said while males tended to disperse, females with young were more likely stay put.

"In the coming months they'll be denning their young," she said.

"If they've got joeys, they're probably less likely to move further distances."

Female northern quolls typically live longer than the males in the species, which often live for just one breeding season.

"Further into the project when we bring in some more boys, if there's girls around, hopefully that will help keep the boys local as well," she said.

A key predator

While the northern quoll is the smallest of Australia's four quoll species, it is often considered the most aggressive.

Ecologist Ben Stepkovitch said northern quolls are "under-appreciated".

"I love working with them because they are so cryptic and not well known, and people don't realise what a ferocious predator they really are," he said.

"A lot of people look at them and think they're a nice, cute, spotty animal but they're a carnivore."

He said finding the species in the wild can be tricky, particularly in the rocky and bushy landscapes they often live in.

Building a robust population

Ms L'Hotellier said as a predator species, quolls have an important role providing balance in the ecosystem.

"All these species have evolved together. There's a balance and it's about restoring that balance," she said.

"It's not just because they're cute and fluffy, but they are an important part of the landscape."

The Mount Zero-Taravale haven's fence keeps invasive predators out, but will allow quolls to escape from the enclosure and naturally repopulate the area.

Mr Kanowski said it is hoped when a thriving population is established there, the quolls will naturally disperse throughout the broader landscape.

"We're hoping that by 2050 they've repopulated the entire Seaview Ranges, which is the ranges between Townsville and Ingham," he said.

Ms L'Hotellier said she looks forward to the day when it is possible to "run into" northern quolls organically.

"When I have northern quolls popping down to the homestead and sniffing around our chook pen, that'll be a sign that this has been successful," she says.