Image for Why the Tasmanian Fox Eradication Program has been worse than a complete and utter failure

Summary: The 10-year fox eradication program has failed dismally because it was initiated as broadacre poisoning based on flawed data and the way it was deployed had absolutely zero chance of eradicating foxes even if they were present.  It had seriously flawed evidence of fox presence from scat DNA analysis, and had no way of monitoring either foxes present or foxes killed. (let alone unintentional native wildlife collateral damage)

Equally as concerning is the high-handed and secretive way in which the Fox Eradication Program (FEP – now the Invasive Species Branch) went about its program.  This was by refusing to engage with credentialed scientists and members of the public who had issues with the program or ideas for improving operational matters, by totally withholding release of internal DPIPWE reports about the various technical issues, and by refusing to release vital information unless forced to by FOI laws or parliamentary questioning.

It has further failed because it has diverted much needed money away from real Tasmanian wildlife management issues such as serious decline in quoll and devil populations, agile wallaby and ferret incursions, and a feral cat population explosion. It has generally corrupted the scientific method and openness as an ideal model for wildlife management by government.  It’s almost complete lack of applied research into novel methods of truly detecting foxes in low numbers has set the scene for future fox incursions with inability to control them if they do actually arrive, establish and start breeding.

These matters are individually discussed in this report with the benefit of hindsight, simple calculations, logic and literature reviews.

1.  The fox eradication program was initiated based on flawed data: Foxes had been known to have been introduced into Tasmania occasionally before the FEP was startrd, but to have not established.  The research work of Ian Abbott   [Abbott I (2011). The importation, release, establishment, spread and early impact on prey animals of the red fox, Vulpes vulpes in Victoria and adjoining parts of south-eastern Australia. Australian Zoologist 35, pp. 463–533]  demonstrating that it is actually quite difficult for an exotic species like the fox to establish in a novel environment should have sounded a cautionary note that foxes allegedly brought to Tasmania would not automatically mean that they would establish.  The well known Allee effect (when populations are low the chance of them persisting is also low) should also have indicated a need for discretion before committing large sums to an eradication program.

As things turned out, it is now exhaustively documented that most of the physical evidence in the form of fox carcasses, scull and blood was very suspect, especially bearing in mind that importing fox carcasses and skins into Tasmania was perfectly legal at the time.  The reports of deliberate fox cub introductions for release were likewise a total beat up. David Obendorf and Ian Rist ( David Obendorf ), if asked nicely, might be persuaded to provide further details here for anyone interested!  In hindsight therefore, it seems unlikely that anyone aware of the facts would say that starting the poisoning program was well advised, no matter what the potential diabolical effects on fauna if foxes established in Tasmania.

2.  The way fox baiting was deployed had absolutely zero chance of eradicating foxes if they had established.  For baiting to be effective in an eradication program it would be essential that all foxes accessed, dug up, ate 1080 poison baits and died.  Absolutely no point if a few per cent remain alive to continue breeding!  What we know quite absolutely from extrapolating from mainland experience is that nowhere near all foxes eat baits and are killed from a single poisoning event.  The 2006 Invasive Animals CRC (  http://www.feral.org.au/wp-content/uploads/2010/03/FoxReview_Web.pdf  ) and 2009 NZ Landcare Research ( http://www.dpiw.tas.gov.au/internnsf/Attachments/PWOD-7WC3KE/$FILE/Fox_2009%20NZ%20Review.pdf  ) review papers cited a likely 77% kill from single poisoning as a reasonable expectation for Tasmania. (based on just 4 published research papers). 

The trouble was that they got the interpretation of some of the published research papers wrong to start with and omitted some less favourable research results. (Parkes and Anderson in the 2009 review just assumed the figure was right without presumably reading the papers themselves). Furthermore, there is the complication of no free feeding in Tasmania prior to poisoning, of abundant available road kill practically everywhere, and the relative unpalatibility of Foxoff relative to fresh meat.  The bottom line is that it would be unrealistically optimistic to expect fox kill from a single poisoning event in Tasmania to even approach 50%, meaning that at least 5 poisonings, in a timely manner, would be needed to even think about the potential to eradicate. 

Then there is the problem that permission is not granted to poison on 10 – 20 % of private land, so even 100% kill on public land would be pointless.  The next problem is that the 1080 poison degrades so quickly on wet land so that according to some estimates Foxoff bait becomes non lethal to many foxes after approximately only 5 days. ( http://oldtt.pixelkey.biz/index.php?/article/nick2/  )  i.e. If just a few foxes didn’t locate and eat the baits for 5 or more days after they were presented bait shyness and aversion could develop according to the FEP independent reviews. 

This means that such foxes would not be able to be poisoned, no matter how many times bait was provided.  Semi-urban areas where poisoning is not possible provide a further potential source of fox recruitment for replacing the small per cent of foxes poisoned in “core” rural habitat, as do areas outside the designated “core fox habitat” areas (varying from between about 1 million hectares and 4 million hectares, depending on the date of the definition of core fox habitat by FEP.  In addition is the certainty that foxes would happily survive in many non-core habitat sites such as under power transmission lines and in pockets of favourable habitat in all vegetation types.

The poison program, on the other hand, only averaged a fraction over 200,000 ha per year (600,000 peak year 2009) and hence would have taken 5 years just to cover the prime core habitat, or 20 + years to cover all the less favourable but still “core” habitat.  Plenty of opportunity then for un-poisoned foxes to double back behind the poison line to continue breeding, even without a private land un-poisoned buffer.

There seems no escaping the conclusion that the blanket poisoning averaging 220,000 ha per year was just like a drop in the ocean in so far as an effective program likely to lead to eradication is concerned. No wonder the IA-CRC scientist Dr. Stephen Sarre (  http://www.canberra.edu.au/media-centre/2012/december/4_foxes/Foxes-in-Tasmania.pdf  ) pointed out that the poisoning program needed to be expanded dramatically if fox numbers were significant as he had (incorrectly) concluded.

3. Fox presence evidence indications from scat DNA analysis was seriously flawed.  The 2012 research paper by Sarre et al (  http://www.canberra.edu.au/media-centre/2012/december/4_foxes/Foxes-in-Tasmania.pdf  ) summarises the FEP’s serious evidence for fox presence in Tasmania. i.e. scat DNA evidence.  I reviewed this paper (  http://oldtt.pixelkey.biz/index.php?/article/letter-to-the-journal-of-applied-ecology/  ) and documented some flaws.  These mainly pertained to the serious lack of data documentation and lack of ability to reconcile the paper’s claim for widespread occurrences of foxes in Tasmania with the total lack of any real signs of fox presence. 

This paper made no attempt to explain away likely false positive results, such as the Bruny island scat, nor false negatives, possible sample contamination and possible scat planting.  If the Sarre et al paper DNA data is correct then there have to be thousands of foxes in Tasmania.  For example just in the “great poo hunt” surveys 1 and 2 there were 18 fox DNA +ve scats found from 4500 sq km searched. i.e.1 per 250 sq km. (or over 30 if “fox like” scat DNA is included!)

Since the search was not especially thorough though, since subsequent analysis determined that none were from the same fox, and since 500 + scats per fox would have been available for collection in any 3 month period, then it is mathematically certain that the true number of DNA positive scats in the search area would have been at least 10 - 20 or more times the number found. i.e. 1 per about 10 - 25 sq km, or a density equivalent to 1500 – 4000 foxes over the 4 million hectares core fox habitat in Tasmania.  If they had multiplied to that number in just a few years it is apparent that they were breeding happily, and would in the last few years since the survey have multiplied to a few times that number again and be painfully obvious.

The assured tone of the Sarre et al paper whereby even the title asserts that foxes are widespread is undermined by factual lapses and inconsistencies regarding fox carcasses and fox-like DNA results, by total lack of scats from the same fox, and by dubious statistical analysis. The entire case for current fox presence in Tasmania evaporates in the absence of credible scat DNA data.  It is a sad day for science when a scientific research paper recommending outlay of several million dollars to expand a contentious poisoning campaign omits to even mention the possibility for false positive and negative results, contamination and scat planting.  It is outrageous that the official “corresponding” author refuses to correspond with fellow scientists and members of the public who politely ask about some confirmation of aspects of the publically funded work.

The only realistic conclusion to be drawn from this paper is that the conclusion (foxes are widespread) and at least some of the analysis is plain wrong (otherwise foxes would be so abundant as to be obvious).  The inherent flaws in this analysis type are highlighted whereby there is no inherent way of knowing whether occasional errors, contamination and scat planting have occurred or not.  No way of knowing then if at least some of the positive DNA scats were real or not.  Interestingly Sarre et al did not mention the possibility that some or many of the foxes responsible for the DNA +ve results might have already been killed by the poisoning? 

4.  The Program had no way of monitoring foxes present. In my opinion effectively relying totally on detecting foxes by scat analysis was a bad mistake because it is expensive to detect the very occasional positive result, because the several-month time delay between collection and result availability limits its use as an eradication aid, and especially because there can inherently be no way of knowing that it represents a real local fox and not an occasional analytical error, contamination or fraud.

Filming foxes and listening for calls on the other hand is relatively simple, cheap and foolproof.  Intensive filming at the bait sites (and elsewhere) would seem a no-brainer first step to detect any foxes nearby and non target animal bait uptake.  For example for a modest capital expenditure of less than $100,000 and diversion of one of the 50 poisoning staff to monitoring duties full time, at least 10 buried baits could be continuously filmed concurrently, for a week at a time, recording to hard disk at moderate resolution, and analysed at high speed at leisure.  (To anyone doubting that this is possible for such a modest cost, I hereby quote this figure as a potential contractor for the next time poisoning starts!)

This would represent approximately 4% of the average number of 13,000 baits laid annually which would be filmed in detail to positively monitor all activity around baits.  If as few as 25 foxes in total even visited one of 13,000 baits in any year, then at least a real record of a fox on video would be almost certain.  Invaluable data on quolls, devils, bettongs, bandicoots etc at bait sites, digging up and consuming baits (or not) would thereby also automatically be obtained.  Surely outlaying a modest amount of money and effort to film just one of those foxes we are assured are out there would be worthwhile, even if just to shut up us sceptics?

These cameras could also record audio, to possibly detect fox mating calls.  It is really criminally negligent, in my view, that no film is available of non target activity digging up, eating poison baits, reacting to the poison and dying or not.  All we have is third-hand vague information, only obtained by a parliamentary question asked by Mr Ivan Dean that confirms that various animals have been noted at a few bait sites by using motion activated cameras.

How incredibly pathetic is that?

An alternative filming technique would be to mount a very high power zoom lens camera with a very high power infrared light on an aircraft and film large areas quite quickly, with each frame capture (20 + per second) representing an area approximately 10 metres x 100 metres.  This would provide sufficient resolution to recognise foxes comfortably.  It would possibly be an invaluable aid for all sorts of night-time activity recording with worldwide applicability to whoever sorted out the initial technical problems.

Recording fox calls would also seem a no brainer as a routine thing to do, as recommended many times by Mr Jim Stevenson.  Since fox calls during the breeding season are apparently audible well beyond a kilometre in distance, and recording equipment is cheap, why not place hundreds of these in likely fox areas at the appropriate time of the year?  Then all that is needed is an automatic mechanism to detect the fox calls from the recording medium.  No doubt this would be a relatively straightforward task for a technically savvy music technician (but maybe not DPIPWE, who like to keep all research in house!)

5.  The Program has no way of monitoring foxes killed.  As we are all fully aware, the FEP procedure is to wait several weeks after poisoning (to give fox scats present before poisoning a chance to degrade) and then attempt to find fresh scats using sniffer dogs.  Four scent detector dogs were deployed after the Landcare Research Review, specifically to detcct living foxes, and expectations were high (e.g.see DPIPWE 2010 - 11 Annual Report (page 42)  ( DPIPWE, 2011 ) “The use of these [scent detection] dogs offers a high level of confidence that no foxes are established behind the baiting fronts” .  This appears rather a classic case of wishful thinking and living or dead fox detector dogs are apparently no longer deployed??

DPIPWE has released no useful information on scat detector dogs, but some information is available from the Landcare Research and Kitchell reports.  The Landcare Research Review provides information to confirm that the FEP poisons at the rate of approximately one bait per 15 hectares, that the success of scat detector dogs in locating scats even in ideal trial conditions only averages about 20%, that a dog with a handler can search a maximum of 100 ha in a 20 minute period, and that a dog can only usefully search for an average of approximately 2.25 hours per day.

The Kitchell Report assures us that “The average over the two years and two months is 53% of baited areas searched post poisoning, but no information is provided on how thoroughly the 53% is searched.  I asked Craig Elliott, FEP General Manager, about this:

Q. “ Kitchell et al say that each dog detector team can check one “survey” area (3 x 3 km) for likely fox scats per day, whereas the FEP Response says one per week! (“50 per year!”)  Assuming FEP is correct, can you say just what proportion of any searched area can be confidently declared fox scat absent? i.e. at what distance can a detector dog identify a fox +ve scat in ordinary conditions (some wind blowing away from the scat, and scats several weeks old?) .  Can you also comment on current status for living fox sniffer dogs and whether they are still being deployed and whether they can also detect fox scats?”

A. His reply: -“ I think the figure is a typo - a dog team will aim for about the 150 mark. The ‘distance detection’ would be highly variable dependent on conditions - wind speed, temperature etc. The dogs are still deployed and still validated for detection work”

Good to have that clarified!! 

6.  FEP refuses to engage with credentialed scientists and members of the public who have issues with the program or ideas for improving operational matters.  This is an absolutely terrible state of affairs.  What a sick joke to have to request Mr Ivan Dean to ask a simple question in parliament for the most basic of information or to have to request simple information via “Right of Information” legislation.  What a failure the “Eradicate” newsletter is at disseminating useful and detailed information (especially compared with the absolutely great Macquarie Island Pest Eradication Newsletter http://www.parks.tas.gov.au/index.aspx?base=13001 ).

What a challenge it is to attempt to get FEP to respond to our sceptical fox presence articles on TT.  For example taunting doesn’t work (e.g. “It seems that we can be as critical as we like because FEP only retreat further into their bunker and refuse to respond.  I don’t know why Stephen Sarre is called the “correspondence author” by J Applied Ecology” – no response). Pleading doesn’t work, (e.g. “ Please though make an exception in this case, or at least release the unpublished data to Bronwyn so that she can properly assess it in her study? – no response)  and offering attractive bets doesn’t work,  http://oldtt.pixelkey.biz/index.php?/weblog/article/The-case-of-the-declining-eastern-quoll/  (comments section – no response for multiple $10,000 bets that single Foxoff baits will kill female eastern quolls ) 

Let’s try this: - Dear FEP,  If you will rationally respond in detail to all the points in this article, and promise to do the same for all serious future articles, and promise to post ALL technical data pertaining to the fox eradication program on line, on your website, then I will personally arrange the eradication of the agile wallabies near Bicheno. i.e. no costs to DPIPWE, all animals very humanely trapped for you to euthanize, sterilize and release, or move to some other wildlife park.  Don’t think you will be able to do it yourself with shooting, whereas I am confident that I can with trapping (ask Greg Hocking for a reference!).  Please respond via a comment in TT ASAP if you are interested? (Some conditions apply)

I really do think that we need simple assurances from all parliamentary parties before the next election that FEP will be instructed to properly engage with the public on aspects of the fox eradication program, especially technical matters.

7.  The FEP has diverted much needed money away from real Tasmanian wildlife management issues.  For example consider the last round of Caring For Our Country Target Area Grants.  Tasmania was listed as a priority site, and approximately 6 people were specifically employed and trained just to assess the applications.  All for nothing though, as ALL the money for Tasmania went straight to the FEP ($2 million) and the Carp Eradication Program).  Consider the need for effective measures to address quoll population decline which is at least known to be occurring. Moreover no one seems to have a handle on the status of bandicoots, bettongs, New Holland mice, and several other animal and bird species, quite apart from many rare plants unknown status and other plants invasive weed status.

It is certain that the almost $50 million focus on burying $5 million underground in Tasmania annually for 10 years, for no tangible result apart from probably killing a lot of innocent iconic native animals, has been at the expense of other important wildlife conservation work in Tasmania.

8.  The almost complete lack of applied research into novel methods of truly detecting live foxes in low numbers in the wild has set the scene for future fox incursions with inability to control them.  So much for the precautionary principle!  Wouldn’t it be a real precaution to learn now how to control an actual fox incursion, rather than blindly spread 1080 poison without knowing that there are any foxes present? 

Let’s all start right now; persuade FEP to let us have an input, and get some research in place for a positive outcome next time.  Let’s forget about next year’s Great Poo Hunt ( http://www.dpiw.tas.gov.au/inter.nsf/WebPages/MMAN-7CNVDF?open  ) and save the money for something not so easily rigged. 

I don’t know about anyone else, but I will be almost certainly be adding some planted fox scats if it goes ahead – purely as an experiment.  I want to show just how easy it is to fool the system. i.e. I will collect some small fox body parts and scats from mainland road kill, dry or freeze them and then add grated pieces to other carnivore scats gathered in Tasmania. I will experiment with moulding some fresh pademelon scats to the shape of fox scats and adding a sprinkle of fox, rabbit, and endemic Tasmanian small animal parts.  I’ll be honest though – and tell them my sample and GPS numbers – but only after they are analysed. 

Let’s see whether they can really distinguish cat scat DNA from cat scat DNA with added grated fox material?  Trouble is that there is no way of knowing how many other people have the same idea, only with less pure intentions, so it is hard to see how useful the hunt can possibly be?  It seems essential though to teach the rudiments of hoaxing technology to the FEP so they can try to learn how to counter it if they are going to persist in relying on scat analysis to detect foxes?

How to prepare for future fox incursions then?  Firstly, I believe we need to get DPIPWE to get outside help (but definitely not the present Technical Advisory Panel which has overseen the debacle to date).  Let’s allocate some money and call for expressions of interest from people from different walks of life with new ideas e.g. hunters, photographers, wildlife biologists, research scientists, university staff and private businesses.  Allocate some money for advanced proof of concept trials, and finally put some government muscle into getting some genuine applied research funding. 

Let DPIPWE do what it does best – get some funding from the federal government, only this time not just for its own staff.   

Ivo Edwards  is an independent research scientist whose current area of interest is exploring interactions between the public and publicly funded government departments.  His focus is on mechanisms and thought processes adopted by the government departments to justify secrecy and thumbing of noses at the public, when they actually are financed by the same people they treat with distain.