Male aggression and sexual coercion in wild West African chimpanzees, Pan troglodytes verus

Sexual conflict has an important selective influence on mating strategies, particularly in promiscuous species such as chimpanzees. Males may coerce females to mate and aggression may inhibit female choice. The effect of male coercion on females has rarely been examined in primates. The present study focuses on male aggression towards females and the influence of male coercion on female choice in two communities of wild chimpanzees in the Tai National Park, Cote d'Ivoire to determine (1) whether male-to-female aggression increases in a sexual context, (2) the frequency, context and efficacy of male-female aggression and (3) the influence of male coercion on female choice. Our results suggest that direct male coercion was relatively rare, was used by less preferred males, and did not seem to function effectively to constrain female mate preferences as neither (1) a general measure of overall male-female aggression nor (2) a specific measure of direct sexual coercion corresponded to male mating success, and (3) male aggression did not correspond to increased female proceptivity or decreased female resistance rates. Lastly, variation in male-female sexual strategies appears to be yet another important realm for behavioural diversity in chimpanzees. This detailed examination of chimpanzee male-to-female aggression emphasizes the importance of carefully distinguishing male and female influences on sexual interactions in light of their disparate reproductive interests. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.