Abstract
Group-specific communication signals are found in many group-living species. One example is group variation in the production of codas, which are short stereotyped patterns of clicks produced in social contexts, by sperm whales, Physeter macrocephalus. However, little is known about how codas are used by groups and individuals. We used the multipulse structure of sperm whale clicks to estimate the size of animals producing codas. Recordings of a single social unit containing nine largely unrelated animals made over a 1-month period yielded 879 codas of 32 distinctive types. We used an automatic technique to measure the interpulse interval of the clicks in these codas because the interpulse interval is closely related to the size of the animal. Ninety-four codas had sufficiently accurate measurements to be included in further analysis. Modes in the distribution of these measurements showed that more than one animal was producing codas. Comparing the measurements within coda types revealed that several coda types were produced by more than one animal. Thus, the codas recorded from these animals represent a shared repertoire, whereby coda production is not limited to a single animal and coda types are shared between individuals within the unit.
| Original language | English |
|---|---|
| Pages (from-to) | 865-874 |
| Number of pages | 10 |
| Journal | Animal Behaviour |
| Volume | 67 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - May 2004 |
Bibliographical note
Funding Information:We thank Godfrey Merlen, owner of the R/V Ratty , without whose efforts the fieldwork for this study would not have happened, and those who assisted in collecting the data: Eddie Muñoz, Fabian Ramirez and Guido Ramirez. The Charles Darwin Research Station, the Galápagos National Park Service, the Instituto Nacional de Pesca and the Armada of Ecuador all cooperated invaluably with our fieldwork. We are grateful to the International Fund for Animal Welfare and in particular Doug Gillespie for allowing us to use Rainbow Click, to Sarah Mesnick for sharing the results of her genetic analyses, and to Paddy Pomeroy for discussions of those results. John Goold was unfailingly helpful in answering our questions about IPI measurement, and Peter Madsen provided useful discussion of his acoustic tag results. The fieldwork was funded by a Natural Sciences and Engineering Research Council of Canada grant to H.W., and L.R. was supported by a Canadian Commonwealth Scholarship and an Izaak Walton Killam Memorial Scholarship. Lars Bejder, Andy Horn, the editor and four anonymous referees gave valuable comments on the manuscript.
ASJC Scopus Subject Areas
- Ecology, Evolution, Behavior and Systematics
- Animal Science and Zoology