Abstract
Inter-group encounters provide a medium whereby inferences regarding the nature of resource competition between conspecific primate groups can be made. Where encounters are aggressive, they may reflect: 1) female competition for access to food; 2) male competition for mating access; 3) indirect male mating competition through defence of food; and 4) male threat of infanticide as a coercive means. These are not mutually exclusive. This study tested whether social vigilance may indicate competitive regime. Individual variations may contextually reflect gender-based competitive strategies. Vigilance was analyzed in relation to the above hypotheses. Encounters did have an impact on vigilance as expected. I argue that vigilance in C. vellerosus is more a function of male behaviour and less related to female feeding competition.
