Mating in bighorn sheep: multiple creative male strategies.

Rocky Mountain bighorn rams obtained copulations by defending single estrous ewes (tending), fighting tending rams for temporary access to defended ewes (coursing), or moving and holding ewes away from other rams beyond the periphery of a traditional tending area (blocking). Coursing and blocking illustrate a feature of many male alternative mating strategies: the ability of males regularly to create mating opportunities.