Complex Social Structure of an Endangered Population of Bottlenose Dolphins (Tursiops truncatus) in the Aeolian Archipelago (Italy)

摘要: We investigated social structure and association patterns for a small population of Mediterranean bottlenose dolphins, Tursiops truncatus, inhabiting the Aeolian Archipelago (southern Italy). Specifically we evaluate role sex age composition, residency interaction with trammel nets on this organization. Association data 23 regularly sighted individuals were obtained from summer photoidentification surveys collected 2005–2012. Using combined cluster network analysis approach, found associations between dolphins hierarchically structured, where two mixed-sex units subdivided into smaller temporarily dynamic groups. non-random long-term preferred in population; however, degree cohesion, residence pattern differed considerably units. Six eight females occurred more resident unit-1; addition, unit-1 had significantly stronger associations, higher associates, lived larger groups less frequently nets. Nine eleven males clustered unit-2 five these males, interacting nets, formed associations. propose that female male associate study area during breeding season some choose to interact reproductive forming distinct but interrelated unit. Other may be associating fission-fusion network, which consists appear join coastal population. cannot exclude specialized net foraging, suggesting foraging technique favor solitary lifestyle. Large group sizes high cohesion could an indication greater protection efficiency detecting, deterring or repelling anthropogenic pressures. Most likely dolphins' organization depends combination socio-ecological, demographic factors.