Scientists have created a 40-square-kilometre sanctuary for native Australian animals that is completely free of feral animals such as rabbits, foxes and cats.

One of the largest rabbit-free areas in Australia has been created in Sturt National Park in far western NSW in a major project preparing to reintroduce locally extinct mammals such as the bilby to desert habitat.

After completing 40 kilometres of specialised feral-proof fencing in October 2018, experts have now completed the mammoth task of eradicating every last rabbit, cat and fox from two fenced exclosures.

UNSW scientist Dr Reece Pedler, who lives in the park, said it had been a been a huge effort to eradicate rabbits, cats and foxes from such a large area.

“This 40 square-kilometre area now represents one of the largest rabbit-free areas in the country – this is an amazing achievement given these deserts supported millions of rabbits in the past, which decimated vegetation, causing soil erosion and the loss of our native fauna,” he said.

In addition to extensive tracking, the team also regularly used remote cameras and spotlight surveys over the last year to make sure that all feral animals were found.

The desert area is now well placed to take advantage of any late summer rain which will support vegetation and invertebrates – the food for the seven locally extinct mammal species the team will soon introduce, including the western quoll, burrowing bettong, two species of bandicoot and stick-nest rat.

“If the rain comes in the next few months, we hope to reintroduce bilbies first,” said ecologist Dr Rebecca West.

Already, the Wild Deserts team has had an unexpected discovery in their current intensive ecological surveys – they caught a threatened plains mouse.

“Excitingly, this is the first time that this small mammal species – which was thought to be extinct – has been recorded in Sturt National Park,” said Dr West.

“It was rediscovered in NSW in 2015. This is all the more surprising given the intense drought that has gripped western NSW and which Sturt is currently experiencing.

“The removal of feral cats, foxes and rabbits will likely set the scene for this species to recolonise the area.”

The team is also expanding the project into a massive training area of more than 100 square kilometres, where these small mammals can take back their desert domain, once they have bred up their numbers.