Helping threatened species survive foxes and fire

Deep in Victoria’s Otway Ranges, Deakin University PhD student Darcy Watchorn is building bushfire shelters for small mammals.

“During Ash Wednesday, and again in the 2015 Wye River fires, we saw the devastating impact of fire on people’s homes”, says Darcy. “But we know much less about what happens to the homes of threatened small mammals, such as potoroos and bandicoots as a result of a fire.”

“Unfortunately, recent research is suggesting that even if they survive the fire, the resulting loss of ground cover makes small mammals more vulnerable to predators such as cats and foxes”.

Darcy hopes the provision of supplementary refuges could become a valuable, cost-effective management tool to mitigate the threat of invasive predators on threatened mammals in the Otway Ranges, with application potential throughout forest ecosystems Australia-wide.

He is currently trialling these shelters in the eastern Otways and monitoring how populations of small mammals respond before and after fire, in areas with shelters and without.

He’ll study how populations of small mammals respond to the shelters, how they use them, and if they help populations to persist – and he’ll pair this information with his studies of predator activity (red fox and feral cat) before and after fire to get a fuller understanding of the mechanisms at work.

The red fox and feral cat have contributed to the extinction of more than 20 native mammal species in Australia and placed many more at risk of extinction. Many small mammal populations in the eastern Otway Ranges have seen significant declines since European colonisation, due to a combination of factors including altered fire regimes and a high-density of red foxes and feral cats.

“New methods for conserving threatened fauna in post-fire environments are urgently needed if further extinctions are to be prevented, especially in the face of a warming and drying climate” says Darcy.

Two currently employed approaches for reducing the post-fire impacts of invasive predators are lethal control (but a number of factors constrain how effective lethal control is and where it can be used) and patchy fires that conserve unburnt refuges (however, this is difficult to achieve in practice and the results are often unpredictable).

Darcy Watchorn is the winner of the 2019 Jill Landsberg Trust Fund Scholarship for his project “Conserving threatened mammals in the face of fire and predation.”

He will receive his award at the ESA’s 2019 Conference in Launceston this November and present the results of his work at ESA 2020.

The $6,000 prize is awarded annually by the Ecological Society of Australia in honour of Australian ecologist Jill Landsberg.