Citation: Melillo, K. (2008). Interspecific interactions between Atlantic spotted (Stenella frontalis) and bottlenose dolphins (Tursiops truncatus) off Bimini, Bahamas 2003 – 2007. Unpublished Master’s thesis, Alaska Pacific University, Anchorage, USA. 68 pp.
Interspecific interactions have been observed in a variety of social animals. Functional explanations include foraging, antipredatory and social advantages. These behaviors are little understood in marine mammals, but are increasingly studied phenomena in sympatric populations. Resident Atlantic spotted dolphins Stenella frontalis) off Bimini, The Bahamas have been the subject of ongoing photo-identification and behavioral studies since 2001. A lesser known population of bottlenose dolphins (Tursiops truncatus) has been observed interacting with the S. frontalis since 2003. The interactions were documented with underwater video using focal animal sampling. Mating or sexual play are the primary activities observed in nearly 50% of these interactions, with male T. truncatus as the initiators. The most likely functional explanation for these interactions is social. The T. truncatus males may be failing to gain access to T. truncatus females because of immaturity or lack of social status. Alternatively, these interactions may be attempts to diffuse aggressive tensions that might exist
between the populations.