Third article: Introducing the polecat

Introducing the polecat by Lizzie Croose

The polecat is one of our lesser-known mammals and many people have never seen or even heard of a polecat. The polecat is in fact a native British mammal, a member of the weasel (mustelid) family and related to the stoat, weasel, otter and pine marten. Polecats were once widespread in Britain and were probably the third most common carnivore in Britain during the Mesolithic period, with an estimated population of 110,000 polecats. The species then underwent a severe historical decline as a result of decades of persecution for protection of poultry and demand for their fur. By the early 20th century, the polecat was on the brink of extinction, having been wiped out across most of Britain and confined to a small area of mid Wales, with Shropshire and Herefordshire being the only English counties where polecats clung on. Thankfully, the polecat’s fortunes improved and due to a reduction in persecution, the population has been recovering since the 1930s.

The national polecat survey

The Vincent Wildlife Trust (VWT) has carried out three distribution surveys to monitor the polecat’s recovery and changing distribution. The most recent survey was completed during 2014-2015 and relied on people letting us know when they’d seen a polecat, whether dead or alive, and include any photos taken. We also asked recorders to do the rather unpleasant and smelly job of collecting dead polecats (i.e. road casualties) and sending them to us for analysis! We were incredibly lucky that so many people engaged with the survey and we received over 1,700 records and almost 300 carcasses. These carcasses have been used for research by PhD student Katie Sainsbury at the University of Exeter, to examine dietary preferences and secondary rodenticide poisoning in polecats (which occurs when polecats eat small mammals which have consumed poison, such as rats).

Polecats marching eastwards

The national survey confirmed that polecats are continuing to expand their range and have now re-colonised much of central, southern and parts of eastern England and today are found as far east as Suffolk and Norfolk and as far south as Devon and Cornwall. On a national scale, the polecat is more widespread today than it has been in over 150 years and has re-occupied much of its former range.

The future for polecats

Today, the picture looks positive for polecats as they continue their comeback across Britain. However, although its conservation status is favourable, there are several threats on the horizon which may hamper the ongoing recovery of the polecat. Firstly, polecats are vulnerable to poisoning from second-generation anticoagulant rodenticides, which occurs when they eat contaminated prey, such as rats. Recent research completed using carcasses collected during the national polecat survey found that 79% of polecats sampled had been exposed to second-generation anticoagulant rodenticides. This figure is worrying as it is a 1.7 fold increase in detection of rodenticides in polecats since the 1990s when the previous analyses were carried out. Secondly, polecats are vulnerable to being injured or killed in traps set for other species, such as rats, grey squirrels, stoats or weasels. On occasions where polecats have the opportunity to take chickens or game birds, this brings polecats into direct contact with humans. In a survey carried out in the 1990s, most gamekeepers classed the polecat as a minor pest due to predation of game and wildlife, although these negative attitudes are countered by the acceptance that polecats control rabbits and rodents and thus provide valuable ‘pest control.’

Overall, the polecat’s recovery can be seen as a real conservation success story and the return of a native species that was once on the brink of extinction is cause for celebration.

The VWT is not currently collecting polecat records, but if you have seen a polecat, you can report your sighting to your Local Environmental Records Centre- http://www.alerc.org.uk/. To find out more about The Vincent Wildlife Trust’s work on polecats, visit http://www.vwt.org.uk/species/polecat-2/.  

Lizzie Croose, Mustelid Conservation Officer The Vincent Wildlife Trust