A three-year national review has found that Australia’s mammal extinction rate is higher than previously thought, and will increase rapidly unless a plan to protect all native species is prioritised.
The Action Plan for Australian Mammals draws on the contributions of more than 200 experts and was co-ordinated over three years by Professor John Woinarski, Professor Peter Harrison and Dr Andrew Burbidge.
Australia’s mammal extinction rate is now the highest in the world, with the rate of extinction continuing more or less unabated since the 1840s.
The major cause is introduced animals.
“There are other threats as well, of course, but the primary threat right across Australia is from feral cats and foxes,” Dr Burbidge told Town and Country.
“Feral cats are primarily hunters of live prey and there are estimates that they catch around six animals per night, though this depends on the size of the animal that they are hunting.”
Feral cats are known to eat everything from medium-sized mammals, largish birds and, when necessary, insects.
“I have been in central Australia when there is drought conditions prevailing and there will be no other animals around and the feral cats will survive by eating centipedes,” Dr Burbidge said.
“They are very adaptable and that’s what has made them so successful and to be able to invade so many different environments.”
Research has been conducted over the last few years into methods that may aid in controlling feral cat populations with several solutions beginning to take form.
“There is a bait called Eradicat, that has been developed by the Western Australian Department of Parks and Wildlife,” Dr Burbidge said.
“It’s still used on an experimental basis, it has been successfully used to eradicate cats from four islands off the West Coast, but there are still issues to be resolved with this method.”
The second successful solution has been to erect predator-proof fencing in an area that has been cleared of feral cats and foxes to allow native animal numbers to recover.
The drawback is the expense and time that it takes to prepare, construct and maintain these areas.
“I think the long-term solution does lie in the area of genetic engineering, biotechnology and to develop something that causes sterility in cats,” Dr Burbidge said.
The review gained widespread media attention when announced several weeks ago, accompanied by several estimates of feral cat numbers that were difficult to fathom.
“I really can’t comment on figures,” Dr Burbidge said.
“People have made various guesses and I don’t know that there is really an established figure, but it is certainly in the millions, there is no doubt about that.
“Knowing the exact number is not important really, knowing that they are widespread and they are having an enormous impact on our native animals is much more important.”
Environment Minister Greg Hunt will officially launch the book The Action Plan for Australian Mammals on July 2.