Synchrony, social behaviour and alliance affiliation in Indian Ocean bottlenose dolphins, Tursiops aduncus
Author(s):
RICHARD C. CONNOR*, RACHEL SMOLKER2 & LARS BEJDER3
*Biology Department, UMASS Dartmouth
2Biology Department, University of Vermont
3Biology Department, Dalhousie University
Male bottlenose dolphins in Shark Bay, Western Australia form complex nested alliances in competition over estrus females. Males cooperate in pairs and trios to guard and herd individual females and teams of two or more such alliances cooperate in mating competition against other alliances. A striking characteristic of male alliance behavior is synchrony; males perform elaborate synchronous displays around females and, more routinely, surface side-by-side synchronously with each other. Not surprisingly, males surface synchronously more often with members of their pair or trio than with other alliances. However, instances of synchrony between males from different but affiliating alliances are more common during group socializing, especially when males are exited around estrus females. The seamless manner in which synchronous surfacing is incorporated into the elaborate male displays suggests a signal function. For example, synchrony between males belonging to different but cooperating alliances may help reduce tension in the company of estrus females. But, whether a signal or an artifact of males swimming close together, synchrony will provide a useful tool for behavioral ecologists interested in dolphin social relationships and mating success. The possible convergence between humans and bottlenose dolphins in the evolution of complex nested male alliances and the use of synchrony in alliance behavior deserves further study.
DOI (Digital Object Identifier, will open in another window)::
doi:10.1016/j.anbehav.2006.03.014
