The red grouse (Lagopus lagopus scotica) is a medium-sized bird of the grouse family which is found in heather moorland in Great Britain and Ireland. It is usually classified as a subspecies of the willow ptarmigan but is sometimes considered to be a separate species, Lagopus scoticus. It is also known as the moorcock, moorfowl or moorbird. Lagopus is derived from Ancient Greek (), meaning "hare", + (), "foot", in reference to the feathered feet and toes typical of this cold-adapted genus, and scoticus is "of Scotland". The red grouse is the logo of The Famous Grouse whisky and an animated bird is a character in a series of its adverts. The red grouse is also the emblem of the journal British Birds. Description The red grouse is differentiated from the willow ptarmigan and rock ptarmigan by its plumage being reddish brown, and not having a white winter plumage. The tail is black and the legs are white. There are white stripes on the underwing and red combs over the eye. Females are less reddish than the males and have less conspicuous combs. Young birds are duller and lack the red combs. Birds in Ireland are sometimes thought to belong to a separate subspecies L. l. hibernica. They are slightly paler than those in Britain and the females have yellower plumage with more finely barred underparts. This may be an adaptation to camouflage them in moorland with higher grass and sedge content and less heather. It is identified by its chut!chut!chut!chut!chut!chuttt.... call, or the Goback, goback, goback vocalisation. The wings make a whirring sound when the bird is disturbed from a resting place. Grouse populations display periodic cycling, where the population builds up to very high densities only to crash a few years later, and then recover. The main driver of this cyclic pattern is thought to be the parasitic nematode worm Trichostrongylus tenuis. However, in his book, V. C. Wynne-Edwards suggests that the primary reason for mortality in grouse population is homeostasis depending largely on food availability and that the 'Grouse disease', due to the parasitic worm Trichostrongylus tenuis is a mistaken diagnosis of the after effects of social exclusion. Distribution and habitat The red grouse is endemic to the British Isles; it has developed in isolation from other subspecies of the willow ptarmigan which are widespread in northern parts of Eurasia and North America. It is found across