Superstars of STEM: Bringing back the Bettong
After an absence of 100 years, an endangered marsupial is returning to mainland Australia. Dion Pretorius reports.
A century ago, the Eastern Bettong (Bettongia gaimardi) was driven to extinction on Australia’s mainland by foxes and cats, but this little marsupial is making a comeback thanks to cutting edge environmental and ecological science at Mulligans Flat Woodland Sanctuary in the country’s capital, Canberra.
In a sanctuary bordering one of the city’s bustling suburbs, Bettongs born in Tasmania are thriving in their new home, and have been breeding so successfully that several generations have been born since their reintroduction in 2012. Categorised as “ecosystem engineers”, the Bettongs are thought to play an important role in the health of surrounding bushland, turning over the soil and encouraging seed germination as they dig for food.
Ecologist Kate Grarock is a member of the team working at the sanctuary, and says the Bettongs are the first of many endangered and at-risk species that are being given new life there.
Preliminary research by one of Grarock’s colleagues, Catherine Ross, has shown that the holes dug by the Bettongs provide a sheltered place for seeds to germinate, in which native plants are more likely to win out over exotic seedlings.
Keys to the success of the Bettong program have been the effective predator controls – which consist of a large fence and constant monitoring to prevent the entry of foxes and cats, and the carefully controlled release and reintroduction of the marsupials.
Recently, the Mulligans Flat team conducted research to determine the most effective way to release the animals to minimise stress and fatalities.
They did this by examining the prevalence of faecal glucocorticoid metabolite (FGM) in droppings – a marker of stress in Bettongs – and comparing the results between two methods of release: pre-release captivity versus immediate‐release.
It was hypothesised that the more time-consuming quarantine of Bettongs prior to release would be a less stressful means of reintroduction. However, the team found there was little difference between the two methods.
Thanks to their careful work to minimise stress and eliminate predators, this project has been ranked highly successful by international standards.
Grarock says the lessons learned during the Bettong reintroduction will be studied and applied by the Mulligans Flat team to support the reintroduction of other endangered and at-risk species, including the Eastern Quoll (Dasyurus viverrinus) and the New Holland Mouse (Pseudomys novaehollandiae).
To learn more about the Sanctuary, visit the Mulligans Flat Woodland Sanctuary website.
Dr Kate Grarock is one of 30 Superstars of STEM featured in this weekly series prepared by Science & Technology Australia (STA). To learn more about the program, visit the STA website.