A long streak of brown and cream fur on the road in February may be a sad sight, but it’s also evidence of a remarkable return: the polecat is back.

Polecats are mustelids, related to badgers, stoats and otters; their name is from the French 'poule-chat' or ‘chicken-cat’ as they had a reputation for killing domestic fowl. This, and their fondness for game bird eggs, led to widespread persecution, so intense that the animals were eliminated from most areas of the British Isles.

They hung on only in the hills and valleys of central Wales where gamekeepers were most thinly scattered. By the beginning of the 20th century, the polecat had become one of the rarest British mammals, brought to the very brink of extinction.

Its comeback was a surprise to many people, naturalists included. From around 1960, polecat corpses were found more often on roads in the Welsh borders with England.

At first they were suspected of being escaped domesticated ferrets or hybrids between polecats and ferrets. Closer examination of their fur patterns and skull features revealed that these were the genuine article and that the polecat was reclaiming its old territories.

As persecution has decreased, polecats have re-occupied large areas of southern and midland England and are continuing to spread north and east.

They hunt by night and are rarely seen alive, so road casualties are important to assess their presence. These casualties often peak in late winter and early spring as roving males travel widely in search of mates.

The young or kits are born in May and fed on a wide range of food including frogs, birds, rats and rabbits. Polecats can live closely alongside us and will bring up their families, even under decking or garden sheds, where they perform a wonderful rodent eradication service.

One aspect of their lives is less popular though: their anal glands produce a strong musky smell, which gives them the well-deserved old name of 'foumart' or ‘foul marten’.

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Illustration by Mike Hughes