An aspect of sexual selection in which males compete, directly or indirectly, for access to females. Amongst red deer (Cervus elaphus), for example, the females have little or no choice of sexual partner, because the males defend their harems against possible rivals. Competition between two stags involves assessment and sometimes fighting.
Some contests between males involve mock fighting. Thus buffalos (Syncerus) and bighorn sheep (Ovis canadensis) charge each other and clash head on in ritualized trials of strength. In other species the fighting is more serious. Among elephant seals (Mirounga angusirostris) male rivalry is intense and often involves fighting. When a male attempts to copulate with a female, she protests loudly, attracting the attention of other nearby males, who attempt to interfere. A male is likely to be successful in copulating only if he is dominant and can ward off his rivals. The female intensifies the competition by her protests and ensures herself a dominant male. Thus while the female does not directly exercise a choice, her behaviour indirectly has that effect. If the female does not protest, the copulation is less likely to be interrupted and a low-ranking male will have a greater chance of success.
Subjects: Zoology and Animal Sciences.