An international collaboration of scientists has reported serious deficiencies in the data and analysis used to justify the controversial 13-year Tasmanian fox eradication program (FEP).
Since its inception in 2001the eradication program was unable to confirm the existence of a single living fox, despite spending funds estimated to exceed $50 million, employing a small army of staff and baiting much of Tasmania with 1080 poison.
A core group of seven scientists consulted with other specialists from around the world. They sought to replicate and assess FEP data using qualitative and laboratory analysis. Some of the findings have already been peer-reviewed and accepted for publication by scientific journals specialising in applied ecology, molecular forensics and wildlife science.
Scientists at two research institutes at the University of Porto (Portugal) found that ‘false positives’ would result from one of the published DNA tests developed for use in Tasmania to identify fox scats. Cattle, pig, rabbit, hare and even Tasmanian devil DNA could be mistaken for fox DNA. The study was recently reported in Forensic Science International: Genetics.
Dr Filipe Pereira, who led this study, said that: “this diagnostic assay can produce ambiguous results. It produces ‘positive’ results when DNA from other species is present in the sample, something that should never occur in a species-specific test. This problem is aggravated when analyzing scats from native predators if the DNA from several other diet species may be present. For example, a scat of a native predator that contains a mix of certain DNA can be wrongly identified as that from fox and even confuse follow up testing of the sample.”
Fox positive scat DNA has been critical to the FEPs claims and approach in Tasmania.
The researchers’ website reports that the detection and distribution of the 61 ‘fox positive’ scats reported by the FEP over 13 years most closely resemble a statistical pattern expected from false positives, or ‘Type one’ error as scientists sometimes refer to it.
Dr Clive Marks, a scientist who has published widely on fox ecology and control, explained: “These data are anomalous. Our analysis showed that the statistical likelihood of the 61 scats coming from a fox population was extremely remote. The patterns of their detection and distribution can be shown to be very different from that expected from a fox population based upon empirical data and past studies”.
A detailed re-analysis of the FEP data, also used to base an ecological model that concluded that foxes were widespread in Tasmania, has been accepted for publication by the highly respected British Journal of Applied Ecology.
The Tasmanian Fox Eradication Program has imported thousands of fox scats from the Australian mainland in order to train fox scat detection dogs and to conduct field experiments. Contamination from imported fox DNA from fox biological materials commonly handled by program staff in an ad-hoc manner is another possible source of false positives.
Another controversial finding was that the number of anecdotal fox sightings in Tasmania, in any month or year, could be accurately predicted simply by the quantity of media generated in the same period. None of the more than 3000 sightings since 2001 have been corroborated with physical evidence of foxes. Despite this, the FEP used these anecdotal sightings to justify the program and to support the conclusion that foxes were widespread in Tasmania.
Reductions in anecdotal sightings were even used to propose that fox baiting with 1080 poison was successfully reducing fox abundance. Somewhat embarrassingly, it turns out that the declines in ‘sightings’ were almost certainly driven by corresponding reductions in the amount of media coverage devoted to the fox program at that time.
The scientists point to the folly of asking Tasmanian residents, living on an island where foxes never established and are unfamiliar, to identify living foxes at night despite trained FEP staff failing to indisputably document the presence of a single fox even once in 13 years.
Dr Marks said that the reliance on uncorroborated anecdotal reports was “pseudoscience that has distracted the program and community from science-based assessments”.
Similarly, the independent researchers argue that opportunistically acquired ‘physical evidence’, also much relied upon by the Tasmanian programme, is not scientific data.
Since 2001, all cases of physical evidence of foxes in Tasmania were provided or ‘discovered’ by third parties who were routinely anonymous or used unverified stories to account for the circumstances of the discovery. At least five cases are indisputably hoaxes. Overall, 14 claims of physical evidence, at one time used by the FEP, had poor evidentiary quality, were incorrectly reported, baseless or unverifiable.
“Scientists generate data under controlled conditions and it is never handed to them by anonymous third parties. That immediately invalidates it,” says pathologist Dr David Obendorf who forensically examined the physical evidence. “The FEP fox materials came to their attention in highly questionable circumstances. The program seemed insensible to the ease with which planting transportable specimens and proven hoaxing confounded their claims. They failed to demonstrate the existence of a living fox population based upon any reasonable evidentiary standard”.
Another study, recently accepted by the American Wildlife Society Bulletin criticises the ‘weight of evidence’ approach used by the FEP. “Claiming nine cases of physical evidence sounds like an impressive tally. But this is misleading when you realise that not a single instance is convincing or of sufficient quality to be treated as scientific data,” said Dr Obendorf.
Associate Professor Graham Hall of the University of New England and former wildlife scientist with the Tasmanian Government was involved in the independent review. “Many of the errors and inconsistencies have their origin in basic scientific process and poor professional rigour. Perhaps the biggest mystery is trying to understand why so many have escaped the attention of past reviewers. We were frequently advised that the program had been extensively reviewed, but our independent analysis raises the question of how rigorous were the reviews? Obviously, you can’t find what you don’t look for”.
But in the case of finding evidence of living foxes in the Tasmanian environment, it seems increasingly apparent that you can’t eradicate what isn’t there either.
• The scientists’ forensic examination of the evidence is on their WEBSITE, here, TWITTER, @Tasmanianfoxes
Seen any foxes? As published in the Hobart Mercury. (Kudelka with permission. www.kudelka.com.au)
• Sunday, Background Briefing: The great Tasmanian fox hunt
Sunday 4 May 2014 8:05AM
A discredited story about fox cubs being released in Tasmania triggered a decade-long hunt for the predators. It was described as the greatest wildlife extinction threat since the last ice age but despite millions of public funds spent on an eradication program, an independent review says there’s been no evidence of foxes living in Tasmania. Ian Townsend investigates.
An independent scientific review says it’s found no credible evidence for foxes living and breeding in Tasmania, even though there’s been a decade-long multi-million dollar program to eradicate them.
The international team of seven scientists is led by the man who helped start the eradication program, Dr Clive Marks.
‘Here is an example where you can propose that something exists when it doesn’t,’ Dr Marks said, ‘and if you follow that narrative with a suitable amount of media and spin doctoring you can get a good proportion of people believing it.’
The team is disputing much of the evidence—including thousands of sightings, several dead foxes and DNA tests—that was used to justify the fox eradication program.
It’s now published its report online, and is also publishing papers in several international science journals.
The existence of foxes in Tasmania has been the basis of heated public debate and media speculation since 2001, when it was alleged three hunters brought up to 19 fox cubs into the island state, raised them and set them free so they could be hunted.
Documents obtained under Freedom of Information show that a police task force never found any evidence at all for the claims, and closed the case in mid-2001.
‘On investigation it became abundantly clear that the original informant had only passed on part of that information, most of which was hearsay and gossip,’ the 2001 report said.
‘The remaining information seems to have come from P&WS [Parks and Wildlife Service] personnel who have relied on rumour and probably “guesswork”. None of the information was confirmed and some was found to be highly suspect.’
This article represents part of a larger Background Briefing investigation. Listen to Ian Townsend’s full report on Sunday at 8.05 am or use the podcast links above after broadcast.
Despite that, Tasmanians have been told over the years that that event did happen. It was the basis for a massive baiting program that covered more than a million hectares of the state.
‘We took action in 2002 when three litters of fox cubs were brought back to the state by people who were identified, but were not able to be charged,’ former Police Minister David Llewellyn told the Tasmanian Parliament in 2006.
‘Certainly the police followed these issues up. I am convinced that those litters were distributed; one in the Longford area, one down the east coast and one south of Oatlands.’
‘It was on that basis we established the effort to try to rid the state of foxes.’
Mr Llewellyn, now an Opposition MP, said despite the original police report, he is still convinced it happened.
‘There were senior people within the Department of Parks and Wildlife who gave me that advice and they were absolutely certain of the fact,’ he said.
‘I initiated a police investigation, which I’m not sure how thoroughly it was done, but there wasn’t enough evidence to follow up from a legal point of view.’
However, one of the hunters named in police documents and cleared by the investigation said he was shocked that anyone still believes the story.
‘I didn’t even understand it back then. It was like, “you’ve got to be joking, that’s absolute bulldust”,’ he said.
‘I mean, there are no foxes in the state. There’s a lot of hunters in the state and they don’t see them. So the people you must be talking about must be the Fox Task Force. They’re the ones who see foxes, nobody else.’
In fact, the Fox Task Force, now the Fox Eradication Program, hasn’t seen, shot, trapped or shown that it’s poisoned a live Tasmanian fox either.
What the fox program has produced as physical evidence for foxes are four already-dead foxes and a skull provided by the public, a DNA sample found in a chicken coop, two sets of paw prints and 56 apparent fox scats.
These items, though, are all being questioned by the new review of the fox program.
‘The difficulty this program had, was it used a great deal of propaganda and public relations to get across its message, but it failed to actually pass the first test which was the onus of proof test,’ said Tasmanian veterinary pathologist Dr David Obendorf.
‘So what we’ve got is a situation where the threat has always been a real threat for Tasmania, but the presence of evidence is completely zero.’
• Tasmanian Times has published articles on foxes for more than a decade (most questioning; some defending the FEP), in the belief that Mainstream Media in Tasmania (and nationally other than Sam Bungey in The Global Mail), was failing in proper analysis; once hosting a $5000 reward for a freshly-killed Tasmanian fox. All those articles are grouped under the Categories, David Obendorf, HERE; Clive Marks, HERE
• Alison Bleaney, in Comments: Well done team- David and Clive – all of you! Real persistence has been shown in producing “the facts” and ensuring that we all know them; thank you! The major issue to fall out is detailed in #4 “Such an uncritical and biased approach to evidence analysis has weakened the credibility of scientific risk assessment processes undertaken by government officials in Tasmania.” Can we trust Tasmanian Government scientific risk assessments? And the answer in the light of the above is “no”. And then of course there are vested interests, the issues with money and so on and so on….Was it always about these issues anyway? It really is a sad tale and at least the Tasmanian Integrity Commission has to start an investigation. If it does not do so…why not? Is the Commission that compromised?
