Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster E35
Höfundar / Authors: Anna Selbmann (1, 2, 3), Filipa I. P. Samarra (3), Lucie Barluet de Beauchesne (4, 5), Tatiana M. J. Marchon (2, 3, 6), Ellen Hayward (7), Jörundur Svavarsson (2), Patrick J. O. Miller (7), Charlotte Curé (5), Paul J. Wensveen (2, 3)
Starfsvettvangur / Affiliations: 1. Þekkingarsetur Suðurnesja; 2. Faculty of Life and Environmental Sciences, University of Iceland; 3. Westman Islands Research Centre; 4. Biodiv-Wind SAS, France; 5. Cerema-Université Gustave Eiffel, UMRAE, France; 6. University of Iceland’s Institute of Research Centres in Húsavík; 7. Sea Mammal Research Unit, University of St. Andrews, United Kingdom
Kynnir / Presenter: Anna Selbmann
Interactions between killer whales and long-finned pilot whales have been observed throughout the North Atlantic, including off Iceland. These interactions appear to be antagonistic, with killer whales avoiding pilot whales. The mechanisms behind the interactions remain unclear but acoustic cues likely play a key role. We tested the role of acoustic signals in the interaction using playback experiments. Killer whales were exposed to pilot whale sound and control stimuli in Vestmannaeyjar in 2021-2023 (n=15 playbacks to eight groups). One whale per group was equipped with a multi-sensor tag and the behaviour of the entire group was monitored from surface observations. To assess behavioural responses to the playbacks, we applied hidden Markov models to the movement and acoustic data of the tags and fitted univariate regression models to a horizontal movement reaction score, calling rate, and group behaviour variables. Results showed an avoidance response of the killer whales, marked by fast, directed movement away from the sound source and increased cohesion and alignment of the group members. Calling rate often increased initially, followed by a decrease. These findings demonstrate that killer whales, the ocean’s apex predators, respond to acoustic signals of pilot whales and likely perceive their presence as a threat. This study provides important insights into the complexity of cetacean behaviour and the mechanisms that structure the dynamics of multi-species communities.