Pregnant quolls with awkwardly bulging pouches have been captured in a video taken at Mulligans Flat Sanctuary, months after it was revealed the species would be breeding in Canberra for the first time in more than 80 years.

It's good news for the species that has been considered extinct on mainland Australia for more than half a century.

General manager of the Woodlands and Wetlands Trust, Jason Cummings, said the reintroduced cat-sized species had been settling in well.

"Our reintroduced eastern quolls are fostering their young in dens, and collecting more nesting materials with awkwardly bulging pouches," he said.

"Our resident bettongs show no sign of letting the new quolls take over, with more than 300 now in the sanctuary and routinely seen on twilight tours."

Fourteen of the spotted marsupials were released in the fenced sanctuary in March.

They were once widespread across south-eastern Australia but were wiped out on the mainland in the early 1960s due to habitat-loss, introduced predators such as foxes and cats, and diseases.

Female quolls can birth up to 20 young after a gestation period of up to 24 days.

The quoll release in Mulligans Flat was part of a $1.8 million Australian Research Council biodiversity project in partnership with the ACT government, the Australian National University, CSIRO and James Cook University.