Dispersal, philopatry, and the role of fission-fusion dynamics in bottlenose dolphins

In this quantitative study of locational and social dispersal at the individual level, we show that bottlenose dolphins (Tursiops sp.) continued to use their natal home ranges well into adulthood. Despite substantial home range overlap, motheroffspring associations decreased after weaning, particularly for sons. These data provide strong evidence for bisexual locational philopatry and motherson avoidance in bottlenose dolphins. While bisexual locational philopatry offers the benefits of familiar social networks and foraging habitats, the costs of philopatry may be mitigated by reduced motheroffspring association, in which the risk of motherdaughter resource competition and motherson mating is reduced. Our study highlights the advantages of high fissionfusion dynamics and longitudinal studies, and emphasizes the need for clarity when describing dispersal in this and other species.