Five eastern quolls have been released into a woodland sanctuary in Canberra's north, decades after they were last seen in the wild.

The mammals can only be found in Tasmania, but 14 will be moved to the Mulligans Flat Woodland Sanctuary this week in an effort to restore native biodiversity.

Australian National University (ANU) Professor Adrian Manning said the quolls had been a missing part of the ecosystem for many years.

"They've been absent from the mainland for about 50 years, and probably in the Canberra region more like 80 or 90 years," he said.

"Habitat loss, foxes and cats, some direct persecution and possibly even disease led to their demise."

It is the first time wild quolls have been moved to an open environment on the mainland.

"They're a small carnivore and they live on insects and small reptiles and mammals and so forth," Professor Manning said.

"Obviously they're important in the ecosystem.

"So bringing them back will be a really important part of our project."

The reintroduction comes after the earlier release of the eastern bettong in 2012, after a similar mainland extinction around 1900.

Several bird species and the New Holland mouse have also had experimental introductions into the reserve.

"We see it as an outdoor laboratory, where we test reintroductions and restoration, and work out the ways to rebuild ecosystems such as the woodlands," Professor Manning said.

"That can then be applied elsewhere in Australia