One in ten fox baits [Compound 1080 poison] disappeared in Tasmania – statewide; one in 5 baits went missing in NW Tasmania. DPIPWE figures show over 160,000 baits were buried across Tasmania to ‘eradicate’ what was claimed to be a widespread but elusive fox population.
In WA, 1080 fox baits has been used under the ‘Western Shield’ protection plan to safeguard WA’s small mammals. The plan was based on the assumption that the local wildlife have a high tolerance to sodium fluoroacetate . In managing the free-ranging now-declining woylie (Bettongia penicillata) population WA authorities were aerial baiting their area of occupancy up to 10 times a year with fox baits. Each bait contains 3mg of Compound 1080.
For the past 6 years WA authorities have been asking themselves ‘where have all the woylies gone?’.
Perhaps the reasons is HERE: Fox baits gobbled up by native species:
Robert Ryan ABC Environment 5 Nov 2014
• Listen: Researchers say WA fox control is missing its mark as native animals steal bait News Online 1 Aug 2014, HERE …
Native animals are taking many of the poison baits distributed to control foxes in Western Australia’s Jarrah forests: http://mpegmedia.abc.net.au/news/audio/201408/rural-wa-fox-bait-ineffective-0107.mp3
MOST OF THE BAITS laid for foxes in Western Australian Jarrah forests monitored by scientists were taken by native animals, calling into question the current fox-baiting strategy.
Lead researcher Dr Shannon Dundas, from Murdoch University, and her team were surprised to discover that when they tracked 100 different fox baits in a quokka conservation area, 48 were taken by quokkas.
“I knew that there wouldn’t be huge numbers of foxes in the forest, but I still expected more to be taking baits,” Dundas said.
Only one of the 100 monitored baits was taken by the target species, the red fox.
Keith Morris, manager of the Biodiversity Conservation Group in the Science Division of WA’s Department of Parks and Wildlife, was not surprised.
“This area has been baited for foxes for at least 10 years,” Morris said. “Where foxes have been reduced through baiting, native animals such as quokkas increase in abundance and are more likely to pick up baits.”
Morris was concerned that the findings of Dundas’s research could be interpreted to suggest that fox baiting programs are ineffective.
“Given the low number of foxes reported, this study actually demonstrates the effectiveness of fox baiting,” he said. “Parks and Wildlife have previously shown that baiting reduces fox abundance by 70 to 80 per cent.”
Morris suggested that a “comparative study should have been undertaken in an area that was not fox baited” and which contained “more, and more naive, foxes”.
Dundas’s research, undertaken over a nine-month period, employed motion sensing infra-red cameras which captured images each time a bait was taken. As well as quokkas, the cameras showed possums, bandicoots, kangaroos, magpies, ravens, and feral pigs all taking more baits than foxes.
It is not all bad news for native animals though, as the poison used in the baits is designed to be harmless at small doses to natives, but deadly for foxes.
Marketed under the trade name “1080”, the active ingredient, sodium monofluoroacetate, is derived from a chemical naturally occurring in Western Australian native plants.
“Many of the species I observed would need to eat many baits for the dose of 1080 to be lethal,” Dundas said.
A long fox history
The red fox was brought to Australia in the mid 1800s by homesick European hunters, and had reached Western Australia by the 1920s.
The fox has been linked to the decline of many native animal populations, including quokkas.
Traditional fox control methods include trapping, shooting and baiting. Baiting is widely regarded as the most effective and selective of these methods.
Dr Dundas is concerned that money and labour is being wasted deploying ineffective baits. “A more effective bating program would should aim to kill foxes with fewer baits.”
She suggested that changing bait presentation may improve selectiveness. “Burying or suspending [baits] may reduce opportunities for non-target uptake,” she said.
Keith Morris is not so concerned. “We know that non-target species will take some of our baits,” he said. “But we also know that baiting reduces fox numbers. That is the aim.”
Rob Ryan wrote this article as part of his science communication studies at the University of Melbourne.