Behavioral Ecology and Sociobiology

, Volume 55, Issue 6, pp 531–543 | Cite as

Whistle sharing in paired male bottlenose dolphins, Tursiops truncatus

  • Stephanie L. Watwood
  • Peter L. Tyack
  • Randall S. Wells
Original Article


The signature whistle hypothesis states that dolphins produce highly stereotyped, individually distinctive whistles when in isolation. The presence of signature whistles has been called into question by recent studies proposing that dolphins produce a shared, simple upsweep whistle when in isolation, and that whistles produced by socializing dolphins are shared across individuals and social groups. This shared repertoire hypothesis suggests that when two animals produce the same whistle type, it is due to sharing the same common repertoire rather than one animal learning to produce the whistle of another. One difference between studies supporting or denying the existence of signature whistles is the method used to classify whistle types. We examined whistle production by 17 free-ranging bottlenose dolphins while temporarily restrained. We used both a quantitative comparison technique similar to that used to support the shared repertoire hypothesis and human judges to classify whistle types and quantify similarity between types. Contrary to recent studies that emphasize shared whistles, overall whistle sharing between isolated individuals was low (25%) and a simple upsweep did not account for the most common whistle type in half of the animals. Some species of birds, bats, and primates with stable social groups use vocal learning to converge over time to one common group distinctive call type. We examined whistle similarity between adult male dolphins that are partners in a close social alliance in order to test whether vocal learning may enable a similar vocal convergence. Whistle similarity was rated very high between partners and low between non-partners by both the quantitative technique and human observers. This suggests that as in songbirds and some other mammals, adult male bottlenose dolphins may use vocal learning to converge on similar whistles as they develop affiliative social relationships.


Bottlenose dolphin Vocal convergence Whistle matching Tursiops truncatus 



We are extremely grateful to Laela Sayigh and her students for the majority of the data collection of the whistles used in this study. We very much appreciate the efforts of Michael Scott and Blair Irvine, as well as a dedicated group of staff and volunteers, to ensure safe and effective handling of the dolphins for collection of the whistle recordings over the years. Aleta Hohn provided age data for individuals for which ages were not determined from observations during birth years. We would like to thank Nancy Dimarzio, Sarah Marsh, Jennifer Miksis, Patrick Miller, Susan Parks, and Rebecca Thomas for performing the similarity comparisons. Deborah Fripp provided assistance with digitization and cluster analysis and Stephanie Nowacek and Edward Owen calculated male pair association data. Three anonymous reviewers, Lars Bejder, and Suzanne Yin greatly improved this manuscript. Funding for the sound data collection, health assessment, and survey/observation program was provided by the Earthwatch Institute, National Marine Fisheries Service, Chicago Zoological Society, Dolphin Quest, NSF, EPA, Ocean Ventures Fund, ONR, and NIH. S.L. Watwood was funded by an NSF Coastal Processes Traineeship, NSF Grant No. SN-9975523, and Woods Hole Oceanographic Institution Academic Programs Department. Data were collected under NMFS scientific permits issued to R. Wells. This is contribution no. 10799 of the Woods Hole Oceanographic Institution.


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Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Stephanie L. Watwood
    • 1
  • Peter L. Tyack
    • 1
  • Randall S. Wells
    • 2
  1. 1.Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleUSA
  2. 2.Chicago Zoological SocietySarasotaUSA

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