LEIGH SALES, PRESENTER: An ambitious conservation project is bringing native animals back from the brink of extinction.

It is in the form of the world's cat troop fence being built 300km outside Alice Springs.

Stephanie Zillman reports.

(Aerial shots of outback country)

STEPHANIE ZILLMAN, REPORTER: This is Warlpiri country, where for millennia Traditional Owners have lived on this land.

It looks pristine but in more recent times, feral animals have changed it ecosystem.

(Christine Ellis-Michael and her mother Alice getting out of a ute speaking Language)

A slice of that land is Newhaven station, a conservation sanctuary where Christine Ellis-Michael and her mother, Alice, are expert trackers.

(Christine and her mother check a metal trap)

Inside this trap, it is good news. They have captured another feral cat.

CHRISTINE ELLIS-MICHAEL, EXPERT TRACKER: We have got now 43 cats in last month and this month.

STEPHANIE ZILLMAN: The feral animals have proved an unbeat ail predator against the region's small mammals. But now there is a catproof fence that lead scientist Dr John Kanowski is a lifeline for small species.

DR JOHN KANOWSKI, AUSTRALIAN WILDLIFE CONSERVANCY: There is ten to twenty species that will only survive in areas like we are establishing here at Newhaven, completely free of feral cats and foxes.

STEPHANIE ZILLMAN: The fence will protect animals like the rufous hare-wallaby, which will become the first even on a list of critically endangered species to be reintroduced to the central desert.

(Night footage of the rufous hare-wallaby)

DR JOHN KANOWSKI: We want those animals back where they used to be. It is important for the environment. It is important for the species. It is important culturally. It is important for conservation.

STEPHANIE ZILLMAN: Since 2017, the last remaining rufous hare-wallabies in Australia, commonly known as mala, have been awaiting their release from an enclosure at Newhaven.

(Night footage of a humane trap closing)

First, they are caught from within their temporary home. Once they are deemed fit for release, they are given a vitamin tonic and fitted with a radio tracking device.

(Scientists handling a rufus hare wallaby and fitting it with a tracking device)

WOMAN SPEAKING OVER WALKIE TALKIE: Today, we have a female in good condition...

STEPHANIE ZILLMAN: The Newhaven team will be keeping a close eye on the mala to make sure their plan is working.

DR JOHN KANOWSKI: There is no technology that allows us to put these animals safely out into the landscape, so the fences are an interim step.

They might be an interim step for ten or twenty years, but they are critical for saving these species.

STEPHANIE ZILLMAN: The Australian wildlife conservancy says once Newhaven is complete the site will be a feral-free area of up to 100,000 hectares. That's twice the size of Manhattan or all of Hong Kong.

(Scientist picks up a carrier and heads outside)

ZAHLIA PAYNE, NEWHAVEN WILDLIFE SANCTUARY ECOLOGY INTERN: Take one over to our release site...

STEPHANIE ZILLMAN: On a cold desert night, Newhaven is buzzing with activity.

ZAHLIA PAYNE: This one is a female. She has a pouch young. I think it's just a little jelly bean one, so it hasn't yet formed and it's still fused.

STEPHANIE ZILLMAN: After 12 years of painstaking planning, the time to release the Mala has finally arrived.

ZAHLIA PAYNE: Bring her nose out, so she goes when she is comfortable, and just let her go and do her thing.

(Rufus hare wallaby hops out of the carrying bag and into the night)

STEPHANIE ZILLMAN: One after the other, staff release 30 healthy adult mala into Newhaven's Spinifex Sand Plains.

(Cameras flash as the animals emerge, surrounded by kids and scientists)

After a tentative few hops, the mala is on its way to repopulating a species many believed would be confined to history.

JOE SCHOFIELD, AUSTRALIAN WILDLIFE CONSERVANCY: That they will actually be living in a space bigger than what their home range is, so, in a sense, it is their return to the wild.

STEPHANIE ZILLMAN: Over the coming months, a further nine nationally threatened mammal species will be returned to Newhaven and a landscape on its way to resembling pre-European settlement.

JOE SCHOFIELD: We are in a situation where the population can start to increase so significantly that we will have numbers of this animal again in Australia that we haven't soon for decades.