The fox that wasn’t there?

Yesterday upon the stair,
I met a man who wasn’t there,
He wasn’t there again today,
Oh, how I wish he’d go away.
Antigonish, Hughes Mearns

When Winston Churchill spoke of a “riddle wrapped in a mystery inside an enigma” he may well have been describing the Tasmanian fox incursion.

Many people believe that foxes are established in Tasmania, yet others believe that a breeding population does not exist and never has. Ten year later, the elephant in the living room is that a number of things don’t seem to add up.

If you believe foxes abound in Tasmania, you are actually stating something quite different from saying you know it for a fact. And when we state that there is evidence that foxes have been introduced to Tasmania, this is not the same as saying that a population of foxes is established.

Irrefutable evidence is just that - evidence that no one can argue about. The buck stops with the scientists to produce irrefutable evidence. This is why we have science, for it is the curse of humanity that arguments about different beliefs are often bitter, but are never conclusive without true knowledge.

Witness testimonials are not and never will be considered scientific data, and science would not work if they were. If we are willing to use sightings alone as proof of the distribution of foxes in Tasmania, we must also be willing to conclude that thylacines (Tasmanian tigers) abound in Tasmania and even mainland Australia (where one private research group claims 3,800 sightings).

If the real distribution of foxes in Tasmania even approximates the many current sightings or the map of the physical evidence alone, then it will be impossible to eradicate them. There’s no comfort to be found in any scientific studies to suggest that the remotest chance exists for eradicating foxes under these conditions, especially if foxes keep popping up in unexpected locations like vulpine mushrooms. There is no precedent for the eradication of foxes using the buried baiting methods used in Tasmania; it is unproven for this purpose and this is clear from many scientific studies.

As you writhe in denial, think about this also. No established exotic vertebrate pest has been eradicated from an island the size of Tasmania, possibly with the exception of coypu (a South American rodent) in the United Kingdom. Foxes on small islands, such as Phillip Island in Victoria, have yet to be eradicated despite ongoing attempts for at least two decades. Phillip Island is more than 600 times smaller than Tasmania, which is the world’s 26th largest island after all; a very big haystack to find a vulpine needle in unless you knew exactly where to look in the first place - which apparently we didn’t.

An extensive baiting effort did not get underway for years after the supposed introduction date of foxes. If Tasmania was invaded by sloths, the speed and magnitude of the response may have been quite capable of effecting their eradication. But foxes work faster than both sloths and bureaucrats.

But hang on a minute, what if the data to support the current distribution of foxes in Tasmania is tarnished, or somehow not what it seems to be? What happens to our conclusions if instead of accepting these results uncritically, we go searching for some “elephants” lurking behind Tasmanian settees?

It was widely reported that someone introduced 11 foxes to Tasmania in 1999. Unbelievably, this has never been claimed to be a factual event, although it remains the quintessential nub of pretty much everything that has followed in some 11 years since. Normally confidential Tasmanian Police Force documents I have only recently viewed are clear that there was insufficient evidence to support this event as factual.

So, isn’t it time to deal with this particular discrepancy once and for all and to everyone’s satisfaction?

The “precautionary principle” demands no actual proof to justify an action, but only a belief that we can’t afford not to act. It sits uneasily with the scientific method, as it can be born of faith and good intentions rather than knowledge sought through testing assumptions and most importantly revision of a hypothesis when it is found wanting. The precautionary principle can be a path to the dark side for a scientist and it is indeed easy to go there through fear alone.

Yet there have been real foxes introduced to Tasmania. The first Burnie fox sailed from Melbourne’s Webb Dock to Burnie in May 1998 and its arrival is undisputed given the physical evidence and video footage.

From 1990 until 1994 I had studied and radio-tracked foxes at Webb Dock so I knew the site and the breeding biology of these foxes quite well. Foxes use seasonal changes in day length to time their reproduction, breeding only once a year and have a very predictable duration of pregnancy. So, I can say with confidence that if the first Burnie fox happened to female, short of a vulpine equivalent of the Immaculate Conception, it could not have contributed to a Tasmanian population of foxes unless others were already there, waiting dockside in Burnie.

Yet in 2003 when the original Burnie fox would have almost certainly been long dead, another apparently road killed female fox turned up very near the same Burnie Port and another fox was reported to have leaped from a shipping container some 100km away in April or May 2001 - the chances of it being pregnant if it came from Webb Dock also being zero. Now, here you might think, two foxes could have met and begun an established population, despite the distance and two-year time gap between their arrivals - but an autopsy showed that the new Burnie fox had never reproduced. It died a spinster.

Strangely it would appear that Webb Dock foxes have a unique attraction for the Apple Isle and this in itself is mysterious. I have long pondered if perhaps the criminal investigation into foxes arriving in Tasmania began on the wrong side of Bass Strait. Yet even though these foxes arrived at different times and places, there is no convincing evidence that they could have been part of a founding population. True, these are foxes we know of and those who favour the “precautionary principle” may never be satisfied with those things we do not know of.

Strangely there has never been unequivocal documented evidence of a fox breeding den in Burnie. Yet after studying foxes in Australian cities for some eight years, I know that breeding dens are quite easy to find, even at low density. After some six breeding seasons at least, if you can’t find dens they are almost certainly not there or the people looking for them are incompetent. Take your pick.

In fact, not one breeding den has been found in Tasmania. This would be irrefutable evidence after all for if would be next to impossible to fake one.

There are dead foxes that have popped up in Tasmania. While the media reports them, unfortunately there has been little appropriate scepticism when it has been most needed. Vital pieces of physical evidence come to light belatedly, anonymously or, as it has been later found, in suspicious circumstances. Some have turned out to be blatant frauds or cases where fraud could have been easily perpetrated. But none amount to confirmation that a breeding population of foxes is established in Tasmania. We remain marooned in the realm of belief - one way or the other, still looking for irrefutable evidence.

The most convincing evidence that foxes exist in Tasmania comes from using a relatively new technique that extracts DNA found in faeces (scats) confirming they came from a fox with a high degree of reliability - it was a technique developed at Monash University and tested in the field by my team. The idea is elegant; if you find a fox scat it is likely to contain traces of that fox’s DNA. It’s evidence that a known fox has been there and you can count the number of individuals from collecting scats marked with their unique DNA. Straightforward, but only if you can be absolutely confident that your fox scats were not planted, contaminated, mislabelled or subject to unknown errors in analysis.

As foxes can defecate some eight times a day and are territorial, that’s an awful lot of fox crap in one discrete home range waiting to be found after a few days, especially if you have a trained dog to help you. In fact, because foxes are strongly territorial, you would expect to find large clusters of scats in one area. And that’s just the problem. Of the 56 fox scats so far identified as “fox” in Tasmania (because not all have been analysed for individual DNA), they do not come from within clusters of positive fox scats.

Of the 15 identified individuals, no two scats have come from the same fox.

Some people suggested that Tasmanian foxes might not be territorial and could behave differently from their mainland counterparts. But if we have a breeding population of foxes established, they must be territorial for a good period of time, otherwise it is simply impossible that they can reproduce after establishing a breeding den - which they must do.

Yet finding very few scats could also mean that our capacity to detect scats is extremely low, meaning that there might be a lot more undetected foxes out there and eradication indeed looks totally impossible. Alternatively there is something amiss, unexpected or fishy going on.

Recently a fox scat turned up on Bruny Island some 50km south of Hobart, suggesting that a fox had taken a boat ride or had swum much further than is typical for foxes (across the d'Entrecasteau Channel). Such an anomaly seems to me to be an indication that we should be urgently double-checking our procedures and assumptions to ensure the scat-DNA data is telling us what we assume it is.

Some critics have not been backward in suggesting that fox scats have been planted in Tasmania or the technique is faulty, perhaps in ways we do not yet know. It’s not nice to hear such claims, but nonetheless they remain valid scepticism until irrefutable contrary evidence is provided.

Yet the individuals who made claims of possible fraud were given the equivalent of a public cyber-flogging by Tony Peacock, the CEO of the Invasive Animals Cooperative Research Centre, who wrote an extraordinary on-line piece that pilloried the very suggestion.

But no one is actually finding fox poo in a Tasmanian paddock in any conventional sense. Instead, people are sending 1,000s of possible fox scats to Canberra for a DNA test and only there is it determined to be from a fox or not - 56 have been positive.

More than a few criminal court cases have collapsed not because DNA-based investigation techniques are faulted or anyone seriously questions the science behind them. Why they collapse is generally because unless you can prove “beyond reasonable doubt” that your entire chain of procedures from sample collection, analysis and until conclusion is beyond manipulation or contamination, you have potentially tainted knowledge.

You may well be beyond criticism, but no scientist is going to take your word for it. The best way to prove it is to use independent review and oversight as scientists must, not snarling at critics from within a closed shop.

A scientist or bureaucrat who takes, directs or influences public money for projects they are intimately involved in is disqualified from advertising themselves as objective and independent in the defence of their own vested interests. This is why science has a process of often anonymous and always independent “peer review”. Scientists get it wrong all the time and it is only by submitting to criticism that errors are found.

So, what is the way forward? Simple, we need some irrefutable evidence, or something close to it and we need it now. The scat-DNA technique can be this irrefutable evidence if we are prepared to go the distance. If the present fox scat-DNA results are correct and support other much less certain evidence it signals the depressing conclusion that foxes cannot be eradicated from Tasmania. So there is a lot riding on this.

Presently we don’t have irrefutable evidence, because some things with the scat-DNA data just don’t add up. From all the current evidence taken together there is dichotomy on offer so you can validly choose to believe that either foxes abound in Tasmania or believe that there is no absolutely convincing evidence that a breeding population of foxes exists.

After a decade, for this saga to be so short on knowledge it is a painful demonstration of how nearly $40 million has bought so little good science.

We need an independent scientific review of the entire application of the scat-DNA technique - and I do mean independent and scientific - look the words up if you’re not sure.

Presently, the issue is wholly and solely scientific and forensic and one of allowing science to work the way it should. The rigour of the scat-DNA technique and the entire chain of procedures and assumptions used to generate results need to pass muster, audited so it can be our irrefutable evidence. It should be assessed and overseen by qualified and totally independent forensic scientists, who are spared being worded up by those with vested institutional interests and sad tales of scientific martyrdom.

If foxes are indeed all over Tasmania it reflects a monumental failure of public institutions and their lack of ability to produce good science: let’s be honest enough to admit this and brave enough to demand higher levels of behaviour and scrutiny in the future.

Kangaroo Island is fox free and I would like to keep it that way. Given the long-lasting three-ringed circus in Tasmania, we simply cannot afford to repeat this folly else were.

But what happens if the DNA-based test and field protocols are not credible? Let’s all hope so. Perhaps the biggest conservation tragedy in Tasmania’s history is instead an expensive case study in the perils of inadequate scientific rigour and review, and the misuse of the “precautionary principle”.

At the very least it might mean that things are not as bad as they presently might seem. Let’s find out, because most likely we can do so if we demand that science does what science should. Stay appropriately sceptical until we have some irrefutable evidence and have a listen to that Gershwin song, remembering that until you have irrefutable evidence - “it ain't necessarily so”.