Whistle rates of wild bottlenose dolphins (Tursiops truncatus): influences of group size and behavior.


Journal Article

In large social groups acoustic communication signals are prone to signal masking by conspecific sounds. Bottlenose dolphins (Tursiops truncatus) use highly distinctive signature whistles that counter masking effects. However, they can be found in very large groups where masking by conspecific sounds may become unavoidable. In this study we used passive acoustic localization to investigate how whistle rates of wild bottlenose dolphins change in relation to group size and behavioral context. We found that individual whistle rates decreased when group sizes got larger. Dolphins displayed higher whistle rates in contexts when group members were more dispersed as in socializing and in nonpolarized movement than during coordinated surface travel. Using acoustic localization showed that many whistles were produced by groups nearby and not by our focal group. Thus, previous studies based on single hydrophone recordings may have been overestimating whistle rates. Our results show that although bottlenose dolphins whistle more in social situations they also decrease vocal output in large groups where the potential for signal masking by other dolphin whistles increases.

Full Text

Duke Authors

Cited Authors

  • Quick, NJ; Janik, VM

Published Date

  • August 2008

Published In

Volume / Issue

  • 122 / 3

Start / End Page

  • 305 - 311

PubMed ID

  • 18729659

Pubmed Central ID

  • 18729659

Electronic International Standard Serial Number (EISSN)

  • 1939-2087

International Standard Serial Number (ISSN)

  • 0735-7036

Digital Object Identifier (DOI)

  • 10.1037/0735-7036.122.3.305


  • eng