This book summarizes the ecology, reproductive biology, and social behaviour of all ten of the extant North American grouse species. It also describes the current status of grouse populations, some of which are perilously close to extinction. The social behaviour of grouse is of special biological interest because among these ten species there is a complete mating system spectrum, from seasonally monogamous pair bonding to highly promiscuous mating patterns. The latter group illustrates the strong structural and behavioural effects of sexual selection resulting from nonmonogamous mating. These influences reach a peak in the development by some grouse species of engaging in mating "leks", arenalike competitions performed by males while attempting to attract fertile females, and also provide opportunities for females to select optimum mating partners. The book includes 16 range maps, 37 line drawings, and 38 photographs by the author, as well as nearly 1,400 literature citations.