SIMON, Jodie L.*; MOORE, Paul A.; Bowling Green State University; Bowling Green State University: Mating as an Evolutionary Advantage of Dominance

Establishment and maintenance of dominance confers an individual certain evolutionary advantages (Wilson 1975). However, the specific benefits, such as increased access to food, shelter, and mates, which a dominant individual accrues, are unknown for many taxa. In decapod crustaceans, dominance hierarchies are readily established within laboratory settings, and are assumed to be established in the field. The rusty crayfish, Orconectes rusticus, form dominance relationships which remain stable for an extended period of time. We infer that the dominant animal within a hierarchy will have increased access to resources in terms of mates. If position within the hierarchy has direct consequences on mating, we would expect differences in the number of copulatory events based on a male�s rank. In this study, a mixed-sex population was videotaped in large semi-naturalistic aquaria during the fall mating season. Dominance indices were calculated based on the number of wins and loses males had in dyadic, agonistic encounters with other males. For analysis, mating behavior is defined here as both the number of mating events as well as the time a male spent performing ritualized mating behavior. If dominance is truly an evolutionary advantage, it should have direct effects on fitness, and therefore mating. Insight into these mating advantages will lead us to a greater comprehension of the benefits of being dominance.