Abstract: Population-level differences in acoustic parameters of delphinid whistles may play a key role in dolphin communication and social interactions by aiding in individual differentiation or identification and may convey other additional information. Concurrent acoustic and video recordings were collected from sympatric species of Atlantic spotted dolphins (Stenella frontalis) and Atlantic bottlenose dolphins (Tursiops truncatus) in two locations in The Bahamas, and the acoustic parameters of their whistles were described. The acoustic whistle parameters of these two sympatric species in Bimini, The Bahamas, were also compared. The mean acoustic parameters of spotted dolphin whistles in the Bimini community were higher in frequency than those of bottlenose dolphins, but bottlenose dolphins produced whistles that had larger delta and higher maximum frequencies than those of spotted dolphins. Spotted dolphins displayed greater use of whistles with broad-band, non-tonal properties. As with other odontocete species examined so far, the two whistle parameters with the highest intraspecific variability in these species were duration and number of inflection points, which may aid in individual differentiation or identification. Interspecific social, sociosexual, and aggressive encounters have been observed between spotted and bottlenose dolphins in The Bahamas, and differences in acoustic parameters between these two sympatric species may enable them to differentiate between conspecifics and non-conspecifics. Comparisons between whistle acoustic parameters in the Bimini dolphin communities and those reported for other spotted and bottlenose dolphin populations are also discussed.
Key Words: Atlantic spotted dolphin, Stenella frontalis, bottlenose dolphin, Tursiops truncatus, acoustic parameters, whistle
Document Type: Research Article
DOI: https://doi.org/10.1578/AM.43.4.2017.364
Page Numbers: 364-377