Identification and characteristics of signature whistles in wild bottlenose dolphins (Tursiops truncatus) from Namibia

Show simple item record Kriesell, Hannah Joy Elwen, Simon Harvey Nastasi, Aurora Gridley, Tess 2014-12-10T08:20:22Z 2014-12-10T08:20:22Z 2014-09-09
dc.description.abstract A signature whistle type is a learned, individually distinctive whistle type in a dolphin’s acoustic repertoire that broadcasts the identity of the whistle owner. The acquisition and use of signature whistles indicates complex cognitive functioning that requires wider investigation in wild dolphin populations. Here we identify signature whistle types from a population of approximately 100 wild common bottlenose dolphins (Tursiops truncatus) inhabiting Walvis Bay, and describe signature whistle occurrence, acoustic parameters and temporal production. A catalogue of 43 repeatedly emitted whistle types (REWTs) was generated by analysing 79 hrs of acoustic recordings. From this, 28 signature whistle types were identified using a method based on the temporal patterns in whistle sequences. A visual classification task conducted by 5 naı¨ve judges showed high levels of agreement in classification of whistles (Fleiss-Kappa statistic, k = 0.848, Z = 55.3, P,0.001) and supported our categorisation. Signature whistle structure remained stable over time and location, with most types (82%) recorded in 2 or more years, and 4 identified at Walvis Bay and a second field site approximately 450 km away. Whistle acoustic parameters were consistent with those of signature whistles documented in Sarasota Bay (Florida, USA). We provide evidence of possible two-voice signature whistle production by a common bottlenose dolphin. Although signature whistle types have potential use as a marker for studying individual habitat use, we only identified approximately 28% of those from the Walvis Bay population, despite considerable recording effort. We found that signature whistle type diversity was higher in larger dolphin groups and groups with calves present. This is the first study describing signature whistles in a wild free-ranging T. truncatus population inhabiting African waters and it provides a baseline on which more in depth behavioural studies can be based. en_ZA
dc.description.librarian am2014 en_ZA
dc.description.sponsorship Nedbank Go Green Fund of Namibia ( = 833f4cd9-323f-497d-ad1f- 9f641b9dfd73), Rufford Small Grants Foundation (, Idea Wild Fund (, Natural Environment Research Council ( uk), University of Pretoria (, Sapienza University of Rome (, and Claude Leon Foundation ( en_ZA
dc.description.uri en_ZA
dc.identifier.citation Kriesell HJ, Elwen SH, Nastasi A, Gridley T (2014) Identification and Characteristics of Signature Whistles in Wild Bottlenose Dolphins (Tursiops truncatus) from Namibia. PLoS ONE 9(9): e106317. DOI: 10.1371/journal.pone.0106317 en_ZA
dc.identifier.issn 1932-6203
dc.identifier.other 10.1371/journal.pone.0106317
dc.language.iso en en_ZA
dc.publisher Public Library of Science en_ZA
dc.rights © 2014 Kriesell et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License. en_ZA
dc.subject Signature whistle en_ZA
dc.subject Whistle owner en_ZA
dc.subject Bottlenose dolphin (Tursiops truncatus) en_ZA
dc.subject Wild dolphins en_ZA
dc.subject Walvis Bay, Namibia en_ZA
dc.title Identification and characteristics of signature whistles in wild bottlenose dolphins (Tursiops truncatus) from Namibia en_ZA
dc.type Article en_ZA

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