Should I trap Mink

[Picidae]

Originally Posted by Jonathan

Huh? How does this question the effectiveness of removing mink? Basically, what it says is there is insufficient research data to establish the effectiveness of trapping.
Cheers
Jonathan

Exactly. As the discussion/conclusions of the research point out, the surveys carried out concluded there was insufficient research data to establish that trapping Mink was an effective means of eradicating mink populations. Interestingly, some of these same arguments have informed the debate over bTB and Badger control, Ruddy Duck culls and Grey Squirrel culls.

I'm not a trapper Jonathon and I know you are so you probably know from lots of first hand experience that trapping Mink ends up with them being killed and in that sense it's ''effective'' for those that are trapped. However, rather than get into an argument over semantics, I'd urge people to read the whole article that Jonathon has kindly linked to.

I have not first hand experience of witnessing the damage that Mink do, so all I could do is post a load of examples off the internet but I'm not in a habit of postulating the eradication of a species from the comfort of my armchair especially when the effectiveness of proposed methods to do so remains questionable both based on moralistic grounds and scientific grounds and in the case of Mink, where the successful reintroduction of Otter is showing evidence of redressing the balance. I simply posted the link to the study carried out which seems quite clear to any one that reads it, concludes that the 'effectiveness' of trapping as a means of Mink control is inconclusive. Their research, their conclusion, not mine.

Re reading my earlier post, I actually missed out a few words from the first sentence of the second paragraph which made what I said rather ambiguous; It should have read;

With regard to Mink control/management, there is some question over the effectiveness of actually removing them through trapping - in other words, if something has not been established, it's open to question.

[vole-woman]

You quote an article that you claim says the effectiveness of trapping hasn't been establised (I will read it, but haven't yet as I didn't really understand the quote you left): Jonathan cites an article that shows clearly that where mink are present and unchecked, they have a dramatic effect on seabirds. So where does that leave us?

"I'm not in a habit of postulating the eradication of a species from the comfort of my armchair"

- Me neither, Picidae, which is why I repeatedly refer back to my fieldwork, and to the experiences of those who've been involved on the ground with water vole conservation for decades. I'm not an academic either, but I do have practical experience.

Waiting to see whether otters do the job will simply be too late for the water vole - and in any case, I've found plenty of otter spraint and mink scat together, so I do wonder whether that argument's been overstated. I hope it hasn't been, but again, the evidence of my eyes and nose suggests otherwise. Or perhaps the ousting of mink by otters takes a long period of time.

"questionable both based on moralistic grounds"

- Well, I think it's questionable on moralistic grounds to leave a native animal which has been with us for millennia to be wiped out in a few years through the stupid actions of man. It was, and is, illegal to release mink into the wild.

[vole-woman]

Right, Picidae, I've struggled through the article, and the gist of it isn't that mink trapping doesn't work, but that the experiment they ran was missing too much data to come up with a conclusion in this instance. I've quoted some of the lines which explain this:

No firm deductions can be made from current studies because of limitations of study design and lack of controls for comparison. Future studies should incorporate a more robust experimental design, including a population estimation before and after the intervention occurs and a control population that is not subject to the intervention.

Due to the lack of control areas within the experimental designs observed decreases cannot be attributed to any single factor.

Lower quality evidence was later incorporated into the review due to the lack of comparators in the studies located.

Standard deviations of the studies were not presented, and there are no control populations. Consequently meta-analyses could not be performed on the data.

None of the datasets extracted contained standard deviations…inferences could not be drawn about potential variance.

As no controls were included in the experimental design, the baseline
comparison and intra treatment variation could not be measured for any of the studies. No replication was carried out for any of the experiments.

The captured studies provided insufficient good quality data to allow meta-analysis to be performed. Thus an overall measure of effectiveness of trapping as a mechanism to reduce mink populations is not obtainable.

Implication for conservation practice: As the review shows evidence of effectiveness of trapping is inconclusive, no recommendations for change in current practice can be given.

The tables at the end are full of "no information" entries. This is like someone leaving a petri dish of water on a hot radiatior, then saying they can't conclude the water had gone down due to heat evaporation because no one had left a similar petri dish on a cool surface. The criticism contained in the report isn't of mink trapping as an effective method, it's self-criticism of a flawed investigation method.

[Non native]

There is no need to trap polecat ferrets apart from islands where they were not native.

They are genetically the same as polecats and as polecats range expands they will interbreed and eventually be incorporated back into polecats of course that is where they originally came from.


Mark

[camo]

This discussion seems to have setteld into a reasonable and useful consideration of the merits of Mink control, which is good and should be what the site is based on. I suspect that all parties now appreciate that where members advocate Mink control it is after much consideration and for conservation reasons.

I would like to focus on a couple of areas of the debate; Non one within riparian groups believe that trapping will have anything more than a local effect on Mink numbers. It is accepted that Mink have now increased to the point where eradication is not a consideration. It is also generally accepted that with the success of Otter populations this is having a positive impact on displacing the Mink from previous strong holds, I suspect through threat rather than confrontation. Whilst not based on scientific investigation i believe Water Voles have survived in back waters and in many cases have been predated out of main rivers. I appreciate Mink still frequent such back waters however it may be the increased cover allows a Water Vole greater protection.

The point of accepting a non native species is an important one and yes everything feeds on Water Voles which has allowed the Water vole to evolve with a high breeding rate to allow for the extreme population fluctuations. However it is a classic case of a step too far and where Mink were inadvertenly introduced Water Voles could not cope with the added skills of this predator. This had the effect of reducing Water Vole populations to below critical mass and we lost local populations due to the specific predator. I guess in time I would like to believe if Water Voles could survive they would evolve and find a defence to Mink but over such a short time we are seeing an important key species being wipped out by the non native invasion.

Yesterday i watched a Mink that came to within 3 feet of my feet this is not the first time this has happened and I have previousely sat with Mink kittens below my feet. I find them interesting and a beautiful animal but their impact on our less glamorous species is unacceptable. I would not contemplate using a "boot" on them as that would be incredibly cruel and i can only accept legal and humane trapping as appropriate. The point of trapping to protect Salmon is also quite clear for me, Salmon are a native species and therefore is as reasonable reason for their conntrol as is Water Voles protection. I suspect that keepers both river and game are hyposensitive about mink as they are seen as another predator sent from a fiery depth to reduce their opportunity of presenting game. I cannot defend their actions but i do understand the pressure they are under and the overall good effect a good keeper has.

To return to my main point of interest and that is the protection of Water Voles; it is because everything eats them they are so important. Across the world their are many examples of what happens when you remove a prey species with the loss of predators resulting. Where we have remaining Water Vole populations we should do everything we can to protect them even if it is just to give "Ratty" time to evolve a defence against the now resident Mink.

Ps I have no problem at all in Owls, Stoat or Herons eating Water Vole as they are "an enemy Ratty knows".

Roy