After an absence of more than a century the western quoll is back in South Australia's Flinders Ranges as part of a trial reintroduction.

Conservation biologist David Peacock came up with the idea seven years ago and accompanied the first quolls on their flight from Western Australia to Wilpena Pound.

"It's just that disbelief, can't believe we're doing it, can't believe it's happening," he said after touching down with the precious cargo.

"You cross the border and you've brought them back into the state for the first time probably since the early 20th century and here to the Flinders (Ranges). I don't think they've been here since the 1880s."

The native marsupial used to be widespread, but predators and a loss of habitat have seen them disappear across most of the country.

Until the relocation, they were only found in the south-west corner of WA where numbers have risen under a state government-run recovery program.

"If a natural disaster happens of any description then they're gone if they're all in the one area," said Cheryl Hill from the Foundation for Australia's Most Endangered Species, which is raising the funds for the reintroduction.

"The more places you can have them the better off they're going to be."

Reduction in fox numbers allows western quoll return

The Flinders Ranges was selected because a 20-year state government-funded baiting program has reduced fox numbers.

Vince Coulthard from the Adnyamathanha people performs a ceremony to welcome back the western quolls. ( ABC: Kerry Staight )

"The landscape has recovered to the point that we can release the western quolls back into the landscape with a reasonable degree of optimism that they'll thrive and be successful," said South Australia's Arid Lands regional manager Stuart Paul.

Forty western quolls, fitted with radio tracking collars, are being brought to South Australia in two stages for the initial release.

The females were the first to arrive in what was an emotional homecoming especially for the local Adnyamathanha people.

"My grandfather saw him. My dad didn't. But I'm proud to say that I've now seen him back on country," said Vince Coulthard in a blessing ceremony before the release.

The nocturnal carnivores were taken at night to their individual release sites at in and around Wilpena Pound and introduced to their new backyard.

Dr Peacock was there to witness one of the animals take her first few steps back on South Australian soil.

"To see that first female come out and run off and go along that log and disappear into the dark and try and find a new home that's really special. That's something that will stay with me forever," he said.

Feral cats remain a threat

Dr Peacock, who works for Biosecurity SA, says the reintroduction will not just protect a vulnerable species, it could help control the local rabbit population.

Dr David Peacock from Biosecurity SA arrives at Wilpena Pound with boxes of western quolls. ( ABC: Kerry Staight )

"They're not going to suppress a rabbit plague," he said.

"What they will do is when rabbits are at a very low level then they may take off that animal."

But first the spotted species has to survive in its new surroundings.

While foxes have been controlled, other predators pose more of a threat, with two of the newcomers killed by a feral cat not long after their release.

"Quolls do live with cats and coexist with them in Western Australia," said project coordinator Dr Katherine Moseby.

"But cats are probably one of the biggest potential threats to the reintroduction."

The second phase of the reintroduction occurs on Tuesday when the males arrive.

They are being released later because they often wander further afield, so the theory is the females will distract them and stop that from happening.

It is also peak breeding time for the normally solitary species.

"Gestation is fairly short. It's only about 18 days," said Brent Johnson from WA Parks and Wildlife.

"So you'll see the product of that breeding very, very quickly."

The trial is the first part of a $1.7 million five-year reintroduction program.

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