Since the 90’s the Vincent Wildlife Trust have been conducting surveys to monitor the expansion of the Western Polecat population in the UK eastwards from its strongholds in Wales and the Welsh borders. The major problem faced by the researchers is that feral Polecat x Ferret hybrids occur quite commonly across much of England and can appear very similar, or even identical to pure bred wild Western Polecats.
When I first became aware of this work during the 2004-06 survey VWT were collecting dead animals (mostly road kill) to assess their ‘purity’ and map the species eastward expansion. I vividly recall finding my first dead Polecat, a clear Ferret hybrid with a ‘blonde’ throat patch on the way home from work in Leicestershire. I also vividly recall phoning the VWT when I found my first decent looking candidate, I think with some naïve notion that they would despatch somebody to collect the thing. Good God no, ‘pop it in a jiffy bag and post it’ was the cheery response. ‘To Edinburgh? Are you seriously trying to tell me that you can mail a dead mustelid and ‘postie’ isn’t going to sling it over the nearest hedge as soon as he gets wind of it?’ That is what I think I said though I shouldn’t be surprised if I just thought it. I must have said something because another thing I have never forgotten was the equally cheery riposte ‘it’s what we do with the Badgers’. How big would a jiffy bag have to be? Imagine the cost of that now. Anyway, lest I dissuade you from the, oh so appealing prospect of collecting dead Polecats the system has moved on. The Centre for Ecology and Hydrology will now send you a special box to meet all your dead Polecat delivery needs. Throughout last year and for the rest of this one VWT are running another Polecat survey and they need specimens. Originally animals were assessed according to skull characteristics but these were subsequently shown to be unreliable and a key using pelage characteristics to separate wild and feral animals was developed. As a result you can now send VWT photographs, if manhandling dead animals is not your thing. Work by Cardiff University has shown that genetic markers can be used to identify wild Polecats and that some hybrids are indeed pretty much impossible to distinguish on pelage so carcasses are still valuable.
Dead animals can also be used to screen for secondary poisoning from rodenticide. Western Polecats will eat rats, the likely source of rodenticide which has been found in some corpses (probably individuals that had been foraging around farm buildings). This may have been the cause of death of the animal I found last August at Napton-on-the Hill which I discovered in a paddock some distance from the nearest road.
Western Polecat carcass Napton-on-the Hill Warks.
I was recently sent the report summarising the findings of last year’s survey and mine was one of only 4 % of the total of dead animals submitted which were not found on roads. There are seasonal spikes in the frequency with which dead animals are found and live ones seen. The first (of casualties) is in March and is thought to be related to the increased activity of males searching for mates. In late summer females with young to feed are thought to account for a second spike (in live sightings) whilst the final one in September is likely to comprise a disproportionate number of inexperienced juveniles.
I have encountered them on the roads in the Upper Leam Valley and it’s catchments on three separate occasions now and it is easy to see why they are so frequently hit. They lollop across as if they have all the time in the world and usefully, if you stop they will generally peer up out of the grass once they gain the verge giving excellent views as they stare back in to the headlights.
The web site of the Vincent Wildlife Trust can be found here http://www.vwt.org.uk/ and details of how to contribute to the Polecat survey can be followed from the home page.
Thanks to Lizzie Croose Mustelid Conservation Officer at the VWT for her assistance in answering various questions relating to this post.