Cooperation experiments have long been used to explore the cognition underlying animals' coordination towards a shared goal. While the ability to understand the need for a partner in a cooperative task has been demonstrated in a number of species, there has been far less focus on cooperation experiments that address the role of communication. In humans, cooperative efforts can be enhanced by physical synchrony, and coordination problems can be solved using spoken language. Indeed, human children adapt to complex coordination problems by communicating with vocal signals. Here, we investigate whether bottlenose dolphins can use vocal signals to coordinate their behaviour in a cooperative button-pressing task. The two dolphin dyads used in this study were significantly more likely to cooperate successfully when they used whistles prior to pressing their buttons, with whistling leading to shorter button press intervals and more successful trials. Whistle timing was important as the dolphins were significantly more likely to succeed if they pushed their buttons together after the last whistle, rather than pushing independently of whistle production. Bottlenose dolphins are well known for cooperating extensively in the wild, and while it remains to be seen how wild dolphins use communication to coordinate cooperation, our results reveal that at least some dolphins are capable of using vocal signals to facilitate the successful execution of coordinated, cooperative actions.
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Data accessibility. The dataset supporting this article has been uploaded as part of the electronic supplementary material. Example movies are available from the Dryad Digital Repository: https://doi.org/10.5061/dryad. 931zcrjjm . Authors’ contributions. S.L.K. and K.J. conceived the study, designed the study, conducted the analysis and drafted the manuscript; E.G., K.D. and C.M. designed the study, conducted the training, trials and behavioral coding; all authors edited the manuscript, provided critical review and gave final approval for submission. Competing interests. We declare we have no competing interests. Funding. S.L.K. was supported by The Branco Weiss Fellowship – Society in Science. This work was supported by a research grant from Jim and Marjorie Sanger to Dolphin Research Center. Acknowledgements. We wish to thank Jesse Fox, Ted Due, Mandy Rodriguez and Jane Hecksher for apparatus design, creation and troubleshooting. We thank Simon J. Allen for providing valuable comments on this manuscript.
© 2021 The Authors.