Robin Master's Thesis
Citation: Paulos, R. (2004). Non-vocal communication in the Atlantic spotted dolphin (Stenella frontalis) and the bottlenose dolphin (Tursiops truncatus): sequential analyses of inter- and intra-specific patterns of behavior. Unpublished Master's Thesis, College of Education and Psychology of The University of Southern Mississippi
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The goal of this project was to increase our understanding of non-vocal communication in the social lives of two species of dolphins, the Atlantic spotted dolphin (Stenella frontalis) and the Indo-Pacific bottlenose dolphin (Tursiops aduncus). The non-vocal behaviors produced by dolphins in various social contexts and the reactions of other dolphins to these behaviors were described and analyzed. Although no specific patterns of behavior (defined as sequences comprised of greater than two behaviors) were found in either species based on lag sequential analysis, significant associations between target events and non-vocal behaviors were identified. Several behaviors were significantly associated with three “target events” (depart, join, and contact) in both study groups including contact behaviors. Spotted dolphins were more likely to touch another individual after joining than before departing (76.47% vs. 28.57%). The Indo-Pacific bottlenose dolphins were equally likely to touch another after joining or before departing (44.44% vs. 57.14%). However, there was no significant difference between species in the use of these behavioral combinations. Both species engaged in reciprocated contact in only two behavioral contexts (mingle and play). The spotted dolphins, however, use a wider variety of contact behaviors than do the Indo-Pacific bottlenose dolphins. Serendipitously, a behavior previously undocumented in the literature was observed in both species of dolphin during data analyses for this study. This behavior was labeled an “oscillating swim”. This swim behavior is defined as a dolphin moving forward while its entire body is involved in a rolling-type movement. The oscillating swim was documented in five social contexts (general social, travel, forage, play, and inquisitive) for both species, but the use of this behavior varied with age (χ2 = 24.241; df = 3; p<.001) as well as by sex (χ2 = 3.98; df = 1; p<.05).