Abstract
Interactions are common among marine species which use sound as the primary form of communication, yet the role of acoustic signals in mediating these interactions remains poorly understood. Long-finned pilot whales (Globicephala melas) are attracted to killer whale (Orcinus orca) sounds, leading to antagonistic interactions. To test whether these interactions are acoustically mediated in both directions, playback experiments (n = 15) using pilot whale and control sound stimuli were conducted on eight killer whales equipped with multi-sensor tags. To assess behavioural responses to the playbacks, we applied hidden Markov models (HMMs) to movement and acoustic data, and fitted univariate regression models to a horizontal movement reaction score, calling rate, and group behaviour variables. The tagged whales exhibited an avoidance response to pilot whale sounds, evidenced by fast, directed movement away from the sound source and increased cohesion and alignment of group members. Calling rate often increased initially, followed by a pronounced decrease. These findings demonstrate that killer whales, the oceans’ apex predators, respond to acoustic signals of pilot whales and likely perceive their presence as a threat, similar to naval sonar. This study provides important insights into the complexity of cetacean behaviour and acoustic mechanisms shaping multi-species community dynamics.
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Data availability
Data and code used in this study (comprising all data used in the HMM and GEEs) are available in the Supplementary Information.
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Acknowledgements
We sincerely thank all the students, fieldwork participants, colleagues and collaborators involved in the fieldwork efforts. Thanks to Lise Pernel and Mathilde Massenet for their help with the playback experiments and to Volker Deecke and Leticiaà Legat for providing recordings and observations of pilot whales used to prepare the stimuli.
Funding
Funding was provided by the Icelandic Centre for Research (Rannís) to FIPS (grant number 217519), PW (grant number 207081) and AS (grant numbers 206808, 239641), as well as from the US Office of Naval Research (grant number N00014-08-1-0984), US Living Marine Resources (project 57), UK Defence Science and Technology Laboratory (grant number DSTLX- 1000159673) to PJOM and the French Direction Générale de l’Armement to CC (grant number 1883003901) and PJOM (grant number DGA011225151). A Jules Verne grant from the Icelandic Centre for Research and Campus France was provided to FIPS and CC. The Science and Research Fund of South Iceland supported AS. This project was funded in part by the generous support of Earthwatch.
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Conceptualisation: AS, FIPS, PJOM, PJW, CC. Data curation: AS, LBB, PJW, CC. Formal analysis: AS, LBB, PJW, CC. Funding acquisition: AS, FIPS, JS, PJOM, PJW, CC. Investigation: AS, FIPS, LBB, TMJM, EH, PJOM, PJW, CC. Methodology: AS, FIPS, PJOM, PJW, CC. Project administration: AS, FIPS, CC. Resources: FIPS, PJOM, PJW, CC. Validation: AS, FIPS, LBB, PJW, CC. Visualization: AS. Supervision: FIPS, JS, PJW, CC. Writing - original draft: AS. Writing - review & editing: AS, FIPS, LBB, TMJM, EH, JS, PJOM, PJW, CC.
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Selbmann, A., Samarra, F.I.P., Barluet de Beauchesne, L. et al. Aversive behavioural responses of killer whales to sounds of long-finned pilot whales. Sci Rep (2026). https://doi.org/10.1038/s41598-026-35574-7
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DOI: https://doi.org/10.1038/s41598-026-35574-7
