The European polecat (Mustela putorius) has made a remarkable recovery in Wales and parts of England following near-extinction in the early 20th century. This recovering mustelid faces ongoing threats from road mortality, hybridisation with feral ferrets, and persecution.
Polecats were persecuted to near-extinction in Britain by gamekeepers in the 19th-early 20th century, surviving only in Wales and border counties. Following reduced persecution pressure, polecats have recolonised much of Wales and are spreading into England. The recovery represents a conservation success story, but the recovery front faces ongoing challenges. Scottish and Irish populations have not recovered as significantly.
Polecats are largely nocturnal, semi-aquatic mustelids that occupy a wide range of habitats including farmland, woodland, moorland edge, and riparian corridors. They are important predators of rabbits, rodents, and amphibians. Home ranges of several km² mean they travel widely and are vulnerable to road mortality across fragmented landscapes. They are largely solitary outside the breeding season.
Road mortality is the most significant identified mortality factor for recovering polecat populations. Polecats follow hedgerows and watercourses that often run parallel or at right angles to roads, creating crossing points. Monitoring road casualty data provides population distribution information and identifies high-risk crossing points where mitigation (underpasses, culverts, wildlife fencing) could reduce mortality.
Feral and escaped domestic ferrets (the domesticated form of polecat) interbreed with wild polecats, creating hybrid populations. The genetic identity of "polecat" populations in Britain is complicated by varying degrees of ferret introgression. Phenotypic assessment using coat pattern characteristics distinguishes pure polecats from hybrids, but molecular analysis provides definitive identification. The conservation significance of ferret introgression is debated—some argue it has limited impact on ecological function.
Like other mustelid predators, polecats accumulate second-generation anticoagulant rodenticides through their prey. Studies have found SGAR residues in a significant proportion of polecats surveyed, with some animals showing potentially lethal accumulations. Reducing unnecessary SGAR use in agricultural and amenity settings reduces the rodenticide burden on recovering polecat populations.