Submission Type
Oral Presentation
Abstract
Bottlenose dolphins (Tursiops truncatus) communicate primarily through vocalizations, of which two primary types are signature whistles (function to convey identity information) and non-signature whistles (function presently unknown). They are also adept at copying other dolphins’ whistles. Currently, knowledge about copies is limited. My project aims to further the understanding of the context of whistle copy production in bottlenose dolphins.
My research investigates whether bottlenose dolphins produce vocal copies in response to playbacks of signature whistles (SW) or non-signature whistles (NSW), using subsets of playback experiments generated between 1989 and 2014 at Sarasota Bay (Florida) health assessments. Using Raven Pro 1.6, I visually identified all signature and non-signature whistles and potential copies that occurred in each of 59 thirteen-minute playback periods. Copies were independently verified by six naïve observers scoring the similarity of response whistles to stimuli on a five-point scale; eleven whistles with a mean score above three were considered “verified copies”.
I examined the association between copy presence/absence and contextual variables such as sex, stimulus whistle type, and recording context using chi-square tests. Dolphin sex was not significantly associated with copy production while type of stimulus whistle (SW or NSW) was associated; dolphins were more likely to produce a copy in response to SW than to NSW stimuli (χ2 = 19.8, P < 0.001), but there were few SW recordings in comparison to NSW ones. Recording context was also associated with copy production; dolphins in a group were less likely to produce a copy than lone individuals (χ2 = 18.4, P < 0.001). Further analysis will investigate differences in whistle exchange rate between signature and non-signature whistle playbacks.
Future work might investigate the role of copies in facilitating certain behaviors, and their importance to the dolphin whistle repertoire as a whole.
Included in
Vocal copying responses of bottlenose dolphins (Tursiops truncatus) to auditory playbacks of signature and non-signature T. truncatus whistles
Bottlenose dolphins (Tursiops truncatus) communicate primarily through vocalizations, of which two primary types are signature whistles (function to convey identity information) and non-signature whistles (function presently unknown). They are also adept at copying other dolphins’ whistles. Currently, knowledge about copies is limited. My project aims to further the understanding of the context of whistle copy production in bottlenose dolphins.
My research investigates whether bottlenose dolphins produce vocal copies in response to playbacks of signature whistles (SW) or non-signature whistles (NSW), using subsets of playback experiments generated between 1989 and 2014 at Sarasota Bay (Florida) health assessments. Using Raven Pro 1.6, I visually identified all signature and non-signature whistles and potential copies that occurred in each of 59 thirteen-minute playback periods. Copies were independently verified by six naïve observers scoring the similarity of response whistles to stimuli on a five-point scale; eleven whistles with a mean score above three were considered “verified copies”.
I examined the association between copy presence/absence and contextual variables such as sex, stimulus whistle type, and recording context using chi-square tests. Dolphin sex was not significantly associated with copy production while type of stimulus whistle (SW or NSW) was associated; dolphins were more likely to produce a copy in response to SW than to NSW stimuli (χ2 = 19.8, P < 0.001), but there were few SW recordings in comparison to NSW ones. Recording context was also associated with copy production; dolphins in a group were less likely to produce a copy than lone individuals (χ2 = 18.4, P < 0.001). Further analysis will investigate differences in whistle exchange rate between signature and non-signature whistle playbacks.
Future work might investigate the role of copies in facilitating certain behaviors, and their importance to the dolphin whistle repertoire as a whole.
Comments
Angela Roles, Oberlin College
Laela Sayigh, Woods Hole Oceanographic Institution