Study
Signature whistle shape conveys identity information to bottlenose dolphins
Janik, Vincent M.; Sayigh, Laela S.; Wells, Randall S.
Proceedings of the National Academy of Sciences, 2006
Wild bottlenose dolphins were played synthetic whistles that reproduced the frequency contour of a relative’s signature whistle with all voice features removed, alongside control contours. Responses were measured as turning towards the speaker.
- Studied in
- Tursiops truncatus
- Sample size
- 14 temporarily restrained wild dolphins tested with playbacks
Dolphins responded significantly more often to the synthetic version of a close relative’s signature whistle than to control contours, despite the synthetic sounds carrying none of the vocal characteristics that would identify the individual producing them.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
The shape of the frequency contour itself carries identity information, independently of voice — a referential property not previously demonstrated in a non-human animal’s natural signal.
How NatureHQ reads it
This is the study that makes the popular phrase "dolphins have names" almost, but not quite, defensible. Stripping the voice out is the whole experiment: what remains is an arbitrary learned pattern that stands for an individual, which is the property a name has. What is missing is the other half of a name — dolphins were not shown here to use the whistle to refer to an absent third party in conversation, and the sample is small and drawn from one long-studied population.
- Fourteen animals from a single population that has been studied for decades and may not be typical.
- Restraint during testing is itself a strong context and could shape responses.
- Turning towards a speaker is a coarse measure of recognition.
Playing a dolphin its relative’s whistle with the voice removed
Dolphins recognise each other’s signature whistles. Are they recognising the tune, or just the voice singing it?
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: Proceedings of the National Academy of SciencesPublished in PNAS.
doi.org/10.1073/pnas.0509918103
This reference was resolved automatically against Crossref on 2026-08-11.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-09.