1.  It should come as no surprise that two foxes are required to reproduce - a male & a female.  A small founding population of foxes - be it in Tasmania or anywhere else - will not disperse willy-nilly and succeed at colonising if those founders disperse so that mates cannot find each other.  Foxes that presumably ‘disperse’ long distances are not going to find a mate if they come from small founding populations.  Usually males disperse further.  This willy-nilly dispersal would counter establishment of a breeding population. The most recent map is suggesting that establishment has not happened!

2.  Foxes don’t wander about willy-nilly either when they are breeding adults. Whilst outside the breeding season they may be less territorial – but generally those individuals stay in what has been described as a slowly drifting territory.  Foxes are generally strongly territorial and will maintain a home range, which will vary in size due to resources (food, shelter etc) – unless their behaviour in Tasmania is quite different.  Working on the assumption that there is adequate food in Tasmania for them, their home range area may to be comparable at least to Victorian rural examples (about 1 km sq) - at least in the breeding season.  It’s true the presence of other foxes may constrain the boundaries of home ranges.

3.  Foxes breed seasonally (once a year) at a predictable time and an average litter of around 4 cubs will stay within or in proximity to the maternal home range for many months – meaning that up to 6 foxes (vixen, dog-fox and cubs) will exist within an approximate focus on the breeding den.  Hence, from around early spring to late summer there is a shit load of scat in specific hot spots.  Unless the proposition is that foxes in Tasmania behave very differently to those on the Australian mainland and the rest of the world.

4.  Foxes live in an established home range/territory and they use their scats to mark their range.  In other words they concentrate their scats within a defined area.  This means if you find one scat, a search around the area is more likely to produce others.  Foxes are not travelling around Tasmania randomly depositing scats over vast areas.

5.  The widespread discovery of scats all over Tasmania (as the map purports) suggests multiple home ranges (see above points 2 & 4).  It may also be contributed to by dispersing foxes, but scats from dispersing foxes will generally be very hard to find in any one area – much harder than in an around an established breeding den territory.  In order to contribute to breeding these dispersing foxes must find a mate and create another fox ‘hot spot’.

6.  The most convincing evidence that foxes exist and are breeding will be a series of genotyped fox scats from one ‘hot spot’ that show relatedness. If foxes have successfully established a breeding den, the two adults ALONE will produce up to 16 scats a day; in a month, that’s 480 scats per month during the breeding season in one discrete home range area. 

My point is that DPIW and IA-CRC have presented no data of related individual genotypes from the one spot.  The recoveries of different genotypes (based on the DNA scat tests) many home ranges apart suggesting that many fox social groups exist.  If you would like to consider ALL the scats ‘confirmed’ to be from foxes (but not genotyped) then there are an amazing number of probable fox social groups all over Tasmania – add the SIGHTINGS as well if you like - that’s a lot of probable foxes.  If this is the case, the absence of a single credible fox body is surprising.

If positive fox scats keep turning up at the same rate despite the Compound 1080-baiting program, do we conclude that the use of baiting as the effective tool of eradication has failed?

I am sorry that the above conclusions are proving to be somewhat unpleasant and that some might not individuals don’t want to hear them.  Can someone provide a contrary explanation? PLEASE!

It would be a good suggestion to ask UK-based Professor Steve Harris (the chairperson of the Fox Review conducted into the Tasmanian Program in 2006) what he thinks, rather than Professor Tony Peacock, who I understand is not an expert in foxes.  My questions to Professor Harris would be:

1.  From your extensive knowledge of foxes, would they be likely to roam about the length and breadth of land masses the size of Tasmania (swagman-style) depositing scats willy-nilly? Or are you likely to find ‘hot spots’, especially at certain times of the year? Hence, if you found a good fresh poo would you suggest the probability of finding others in an ESTABLISHED home range is quite good, especially during and after the breeding season?

2.  If you accept the fox-scat data and sightings as accurate, would you suggest that this is more than likely to imply that there are many social groups of foxes now in Tasmania and not a small number of highly mobile foxes defaecating and avoiding the buried Foxoff baits?

3.  After almost 10 years if we have an established breeding population of foxes in Tasmania, which has the best chance of success?  (1) Building an igloo in hell, or (2) assuming that Tasmania can eradicate foxes with the current approach? 

Please correct me, but I understood, the only example of successful eradication of an exotic vertebrate pest on a land mass the size of Tasmania was the eradication of a rodent in the UK? 

David Obendorf
IT seems that the debate might be assisted if we consider a few issues about fox biology that can be found freely in many research documents, books and published papers.  This is Fox 101, but it might be worth considering.