Formerly extinct quoll reintroduced to mainland Australia after 50 years

The eastern quoll has been reintroduced into mainland Australia more than 50 years after the population was forced into extinction.

Wildlife authorities have released 19 marsupials into Booderee National Park in Jervis Bay, south of Sydney, to boost the local ecosystem by eating insects and pests.

WWF Australia's rewilding program manager Rob Brewster said the species are hoped to eventually call the mainland home again decades after they were driven extinct.

READ MORE: Scammers force students to fake their own kidnapping, demand ransom

"Around the turn of last century, there was a population crash," he said in a video.

"That crash happened at about the same time as foxes were establishing themselves in Victoria and sweeping across Australia and we think that is probably the key factor for their eventual extinction from mainland Australia.

"Now, they are only found in Tasmania."

Today's reintroduction in New South Wales is a significant move.

A fence will be put around their new home at the park to protect them from foxes.

READ MORE: Trainee nurse killed in Sydney home explosion identified

"What the strategy involves here is breeding enough up behind the fence, getting them aware and savvy when it comes to predators," Brewster said.

"Once we have enough to test beyond the fence reintroductions, then we can start thinking about trying to test getting them back out into the wild."

The eastern quoll is a carnivorous marsupial that largely eats insects, small rodents, reptiles and birds.

It is an endangered species threatened by dogs, cats, foxes and cars on the roads.