Journal of the Marine Biological Association of the United Kingdom




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Observations of rough-toothed dolphins (Steno bredanensis) off the coast of Utila, Honduras


Stan A.  Kuczaj II a1c1 and Deirdre B.  Yeater a1
a1 Department of Psychology, Marine Mammal Behavior and Cognition Laboratory, 118 College Drive #5025, University of Southern Mississippi, Hattiesburg, MS 39406-5025, USA

Article author query
kuczaj sa   [PubMed][Google Scholar] 
yeater db   [PubMed][Google Scholar] 

Abstract

Local dive shop operators and fishermen report that rough-toothed dolphins (Steno bredanensis) are frequently encountered off the coast of Utila, Honduras, (16°05'46.5"N 86°55'47.8"W). Our observations suggest that at least some of these animals may constitute a resident population, although the extent of the resident group's home range has not been determined. Twenty-eight rough-toothed dolphins were identified using photo-identification techniques, 15 of which were re-sighted on two or more occasions. The 12 animals that were re-sighted four or more times were typically seen together, suggesting that they constitute a stable social group. At least one of these dolphins is an adult male, and his continued presence in this social group may reflect a social structure for rough-toothed dolphins that differs from that described for other dolphin species. Social interactions often involved tactile behaviours such as pectoral fin rubbing and side rubbing. The observed dolphins sometimes expressed interest in the research vessel and other boats by approaching, and on separate occasions examined a hydrophone and slow moving propeller visually and echoically. Overall, our behavioural observations suggest: (1) synchronous behaviours and ‘tight’ groupings are common while rough-toothed dolphins are travelling; (2) tactile contact is an important aspect of social interactions for rough-toothed dolphins; (3) cooperative behaviour occurs during play; and (4) rough-toothed dolphins are curious.

(Published Online February 26 2007)
(Received June 16 2006)
(Accepted October 17 2006)


Correspondence:
c1 Corresponding author, e-mail: s.kuczaj@usm.edu