The Nature of Social Relationships in Bottlenose Dolphins (\u3ci\u3eTursiops truncatus\u3c/i\u3e): Associations and the Role of Affiliative, Agonistic, and Socio-Sexual Behaviors

Little is known about the specific behavioral exchanges that occur on a day-to-day basis between dyads of bottlenose dolphins (Tursiops truncatus). This thesis assesses proximity between dyads (~ 2 meters) and the proportion of time that is spent in either an affiliative, agonistic, or socio-sexual context within age/sex pairings of dolphins in order to better understand the nature of social relationships in this species. Observations of bottlenose dolphins housed at the Roatan Institute of Marine Sciences, collected in 2010, provided 10.5 hours of underwater footage for assessment of association coefficients and proportions of interactions. These data suggested similar patterns to previous studies on bottlenose dolphin association patterns and interactions. Mother-calf dyads were found to share the highest coefficients of association, followed by male-male, female-female, and male-female dyads. Four classes of association coefficients were defined for the population: low, medium, medium-high and high. Regardless of which class dyads fell into, affiliative behavior was the most prevalent context recorded, followed by agonistic, and then socio-sexual contexts. This same pattern was also found regardless of which age/sex categories the dyads were placed. This study is the first to quantitatively assess association patterns with affiliative, agonistic, and socio-sexual behaviors in this species concurrently and reveals that the social relationships of these dolphins are predominately affiliative in nature. Furthermore, the patterns of social relationships observed appear to be consistent with sex-specific reproductive strategies