What is the rarest mammal in Britain? The pine marten, perhaps? The red squirrel? Water vole? Well, a 2018 study led by The Mammal Society, which determined that one in five British mammals face a high risk of extinction here, identified three species as the most endangered. One was the Scottish wildcat, which we’ve already covered on this blog; the rather vague estimate of between 30 and 430 pure, or almost pure, wildcats still live in the remote corners of the Scottish Highlands.