Western capercaillie

The western capercaillie, Tetrao urogallus, is the largest living grouse, a heavy forest bird found across northern Europe and the Palearctic. Males and females differ more in size than in almost any other living bird: a cock averages around four kilograms and can reach nearly seven, while a hen weighs about half as much and is browner, with black and silver barring above. Both sexes carry feathered legs and a bright red patch of bare skin above each eye. The species keeps to old, open coniferous forest with a thick ground layer of bilberry and other Vaccinium plants, eating mainly those leaves and berries in the warm months and conifer needles in winter, when it feeds almost constantly and relies on grit and long intestinal caecae to digest them. It is renowned for the cock's courtship display on traditional courting grounds in spring. The species is rated least concern worldwide, yet populations in central Europe and Scotland have declined sharply, driven by habitat loss, deer fences and predation.