Variation in the whistle characteristics of short-beaked common dolphins, Delphinus delphis, at two locations around the British Isles
Ansmann, I.C.; Goold, J.C.; Evans, P.G.H.; Simmonds, M.P.; Keith, S.G. (2007). Variation in the whistle characteristics of short-beaked common dolphins, Delphinus delphis, at two locations around the British Isles. J. Mar. Biol. Ass. U.K. 87(1): 19-26. https://dx.doi.org/10.1017/S0025315407054963
In: Journal of the Marine Biological Association of the United Kingdom. Cambridge University Press/Marine Biological Association of the United Kingdom: Cambridge. ISSN 0025-3154; e-ISSN 1469-7769, more
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| Authors | | Top |
- Ansmann, I.C.
- Goold, J.C.
- Evans, P.G.H.
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- Simmonds, M.P.
- Keith, S.G.
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| Abstract |
The vocal repertoire of many delphinid odontocetes includes narrowband tonal whistles used mainly for communication. The aim of this study was to describe the whistle repertoire of short-beaked common dolphins, Delphinus delphis, recorded in the Celtic Sea between May and August 2005. The 1835 whistles recorded were classified into six broad categories and 30 sub-types, of which simple upsweeps and downsweeps were the most common. Furthermore, the parameters duration, inflections, steps and various frequency variables were measured. The whistles covered a frequency span from 3.56 kHz to 23.51 kHz and had durations between 0.05 and 2.02 seconds. Whistle parameters varied with behavioural context, group size and between encounters. The whistle repertoire of Celtic Sea common dolphins was compared to that of D. delphis from the Western Approaches of the English Channel, recorded during a survey between January and March 2004. The relative abundances of the broad whistle types did not differ between the two locations, but most whistle parameters were significantly different: almost all frequency variables measured were significantly higher in English Channel whistles. This may indicate some degree of population structuring of short-beaked common dolphins around Britain. Alternatively, the common dolphins in the English Channel may have shifted the frequencies of their vocalizations up to avoid masking by low-frequency ambient noise produced by high levels of vessel traffic in this area. |
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