Conservationists will reintroduce rare eastern quolls and two mouse species at Mulligans Flat, North Canberra, in ongoing studies with implications for ecosystems in Australia and abroad.
Last seen on the mainland in the 1960s the eastern quolls, as well as yellow-footed antechinus and eastern chestnut mouse, will join a thriving population of endangered bettongs in a long-term experiment on ecosystem restoration.
The project is worth about $1.4 million. Australian Research Council will provide $557,000 over three years, recognising Australia has the world's highest rate of mammal extinction, which has reduced biodiversity.
Researchers use the 485-hectare woodland sanctuary enclosed with predator-proof fence at Mulligans Flat to learn the best way to improve ecosystems.
They believe small mammals such as bettongs, also known as the kangaroo rat and no longer seen in the mainland bush, act like eco engineers improving the soil.
Conservation biologist Dr Adrian Manning said following the successful reintroduction of bettongs at Mulligans Flat, the next logical step was to reintroduce three new species.
Dr Manning said the insectivore yellow-footed antechinus were in Canberra until the 1980s. The herbivore chestnut mouse survived in isolated populations along the coast and carnivore eastern quoll was a smaller relative of tiger quoll still occasionally found in the Canberra region.
About 30 quolls from both the wild in Tasmania and captivity will be monitored as they adjust to the woodland.
When bettongs from Tasmania were first released at Tidbinbilla and Mulligans Flat 75 per cent of the females had pouch young. In the latest monitoring, 91 per cent had pouch young.
"They are thriving particularly with this wet weather, although it is pretty miserable for human beings, the bettongs love it," Dr Manning said. "It helps their favourite food, the truffle."
He said century-old native trees around Canberra germinated in soils turned over by bettongs.
"We often forget our woodlands had all these species running through them,'' Dr Manning, from the ANU's Fenner School of Environment and Society, said.
"This is where focus is on ecosystem engineers, species which manipulate or manage an ecosystem, improve it for themselves and others.
"Bettongs dig the soil for their favourite food which is truffles. In doing so they open the soil up and make it more permeable for water, change the chemistry and incorporate carbon, leaves and so on into the soil.''
Canberra scientists formed a research partnership with the ACT government and CSIRO about 2004 in established protected woodlands at Mulligans Flat. Their aim is to learn how to improve biodiversity and experiment on returning rare mammals in a protected area to gather information for their wider release.
Reintroducing them beyond protective fencing is still years away.
"Foxes and cats have been the real issue in Australia for a lot of our small mammals. If we can control them with fences or pest control beyond a fence, we really have the prospect of bringing these animals back," Dr Manning said.