POISON baiting programs are highly effective for reducing populations of the red fox, according to a new study by UWA, DEC and the Invasive Animals Cooperative Research Centre.
Since its introduction to Australia in the 1870s, the red fox (Vulpes vulpes) has become a significant burden to agriculture and a threat to biodiversity costing an estimated $227 million a year in lost productivity, amenities and control programs.
The red fox is also a serious concern as a potential vector of rabies, if the virus were to enter Australia.
The most widely used method of fox control are baits injected with the poison sodium flouroacetate, more commonly known as 1080.
Baiting is conducted by hand, or by aerial drops—both costly and time consuming.
Despite this, evaluating the effectiveness of baiting has been problematic; foxes are difficult to observe and very wary of traps.
Lead author of the study Dr Oliver Berry says, “Eradication programs have been evaluated before, but in the past it has been difficult to have great confidence in them, because it has relied on indirect indicators of fox abundance, like number of footprints detected.”
The study used non-invasive genetic tagging to evaluate the effectiveness of a control program in Mid West WA.
Instead of relying on traditional mark recapture methods, the team used sticky wicket hair snares to capture fox hairs. The hairs were then analysed for a DNA fingerprint before and after baiting with 1080.
“I was surprised at how readily foxes would leave hairs in our sticky wicket hair snares, and how good the DNA quality was. This made it easy for us to identify a large number of individual foxes without needing to catch them or even see them,” says Dr Berry.
The study was able to demonstrate 100% mortality and a coincident reduction in fox density in the study area, effectively to zero.
As well as considerably reducing losses to agriculture and biodiversity through removal of red fox predation, the post baiting density was also sufficiently low to prevent the spread of rabies.
“This new, non invasive capture method proved more effective in evaluating control programs and estimating density and survival of Australia’s most expensive vertebrate predator.”
The study is part a larger research and development program funded by the Invasive Animals Cooperative Research Centre. It aims to reduce the impacts of invasive species on Australian agriculture and biodiversity.