Introduced cats and foxes are finding native animals easily exposed by a loss of habitat due to fire and it is pushing some species to extinction.
Research using infrared cameras and GPS trackers is showing the feral animals cover more ground in greater numbers after fires and their diet includes more native species.
Bronwyn Hradsky and Craig Mildwaters from the School of Ecosystem and Forest Sciences at the University of Melbourne have been working in Victoria’s Otway Ranges and the Glenelg region.
They monitored the effects of a 1200 hectare prescribed burn using 54 motion-sensing cameras set out before and after the fire, and a similar layout in a non-burnt forest 10 kilometres way.
“A lot of foxes were moving between forests and farmland and they travel up to about 6 kilometres a day.
“They’re targeting parts of the farmland where there’s spare food, where farmers are dumping carcasses sometimes.”
Desert species pushed to extinction
Professor Chris Dickman from the University of Sydney says the impact of foxes and cats after fires in arid areas is catastrophic.
He has been studying native animals in the desert for a decade.
Professor Dickman says populations of the desert mouse and mulgaras have been reduced for long periods and sometimes to extinction.
Professor Dickman believes creating artificial homes for native fauna after fires could be a solution.
“We’ve been experimentally manipulating artificial structures made of chicken wire mesh and these seem to be used quite intensively by native small mammals,” he said.
“At least in the direct aftermath of a fire, they can provide a refuge where local populations may be able to persist.”
He has been trialling the shelters in far western Queensland and it has been identified to have helped some birdlife as well.
Other experiments with logs and rocks in forest environments have also worked.
Controlling feral animals with 1080 baits is another way of managing the problem, but cats prefer live prey.
“A new technique is being trialled using infrared cameras in the bush that trigger a toxic spray,” Professor Hickman said.
“When a cat goes past an infrared beam it sprays a gel that lands on its shoulder or flanks.
Professor Dickman says the spray is not practical over large, remote areas and he said he believed the problem with cats may grow as bigger predators like dingoes are removed from the landscape.
“There’s some evidence that the demise of the Tasmanian devil in many areas, due to the facial tumour disease, is having the effect of releasing cats with negative consequences for native fauna,” he said.