Relationships among Mountain Sheep and Their Predators

Understanding of the effects of predators on prey is an ongoing learning process. Our objective is to present the key literature on the effect of predators on mountain sheep (bighorn [ Ovis canadensis ], thinhorn [ Ovis dalli ]). Part of the reason these relationships are so difficult to understand is that many ecological communities remain highly altered compared to their original situations, and restoring fully functioning ecosystems is a substantial challenge. Another challenge to understanding predator-prey relationships is the complexity of the relationships among multiple prey and predators that occupy the differing landscapes inhabited by mountain sheep. Although many species of predators prey on mountain sheep, mountain lions ( Puma concolor ) may be the predator with the greatest limiting influence on mountain sheep, due in part to the differences in how they, as stalking ambush predators, hunt when compared with coursing or opportunistic predators. The small, isolated populations of mountain sheep are where those secretive felids are apt to have the greatest influence. Attempts to attenuate the influence of predation on mountain sheep through lethal removal of predators or habitat alteration have been effective only in those areas where small, isolated populations of mountain sheep occur, or in xeric areas where limited alternative prey exist. Predation management should include more than lethal removal of predators and should consider managing the abundance of other prey, other predators, and habitat.