Meeting Abstract
Social living, while adaptive in terms of enhanced access to mates and predator avoidance, also comes at a cost in terms of increased competition for resources and limitation regarding an individual’s opportunity to mate. As such, competition in social groups often leads to the formation of dominance hierarchies, established and maintained by agonistic interactions. These hierarchies often serve to ameliorate within-group conflict and reduce the costs of fighting conspecifics. The most frequently studied dominance hierarchies are those observed among males under conventional sex-role mating systems in which reproductive success is highly variable for males, and dominance is most often correlated with reproductive success. In such situations, females are generally considered to play a passive role, selecting from available dominant males. However, females do interact with each other social and potential exists for the formation of dominance hierarchies among females as well. It is therefore important to ask whether female dominance influences reproductive success either through female-female competition or male choice for female dominance. The maternal mouth-brooding lekking cichlid fish Astatotilapia butroni provides an interesting opportunity to study female dominance hierarchies. We show that female biased operational sex ratios increase intra-sexual aggression within females, yet despite the heightened aggression, the dominance hierarchy remains relatively stable. The aggressive behavior of the females correlates with reproductive stage and suggests that females may in fact be competing for opportunities to mate.
