STOAT Three British creatures are renowned for turning wholly white in winter: Ptarmigan, Mountain Hare and Stoat. Our warming climate, however, may have started to make a mockery of the latter’s ermine camouflage. The Stoat’s pituitary gland controls if and when to moult into white pelage, reacting to cues in temperature and day length. With less winter snow with which to blend, fewer stoats transform their appearance (and those that do tend to live farther north). Most stick with the same colour scheme year round.