Print Email Facebook Twitter Predator sound playbacks reveal strong avoidance responses in a fight strategist baleen whale Title Predator sound playbacks reveal strong avoidance responses in a fight strategist baleen whale Author Curé, C. Doksæter Sivle, L. Visser, F. Wensveen, P.J. Isojunno, S. Harris, C.M. Kvadsheim, P.H. Lam, F.P. Millewr, P.J.O. Publication year 2015 Abstract Anti-predator strategies are often defined as ‘flight’ or ‘fight’, based upon prey anatomical adaptations for size, morphology and weapons, as well as observed behaviours in the presence of predators. The humpback whale Megaptera nova eangliae is considered a ‘fight’ specialist based upon anatomy and observations of grouping behaviour and active defence when attacked by killer whales. However, the early stage of humpback whale anti-predator strategy, when the prey detects the presence of a distant potential predator that may not have perceived it, has never been described. Our aim was to experimentally examine this initial stage of anti-predator responses. Humpbacks are likely to hear well at the frequencies of killer whale vocalisations, thus the perception of killer whale sounds could trigger anti-predator responses. To address this hypo thesis, we played mammal-eating killer whale sounds to 8 solitary or paired humpback whales in North Atlantic feeding grounds and monitored their behavioural responses. We found that predator sound playbacks induced a cessation of feeding, a change in the diving pattern and a clear directional and rapid horizontal avoidance away from the speaker. Interestingly, in mothercalf pairs with young calves, the directional horizontal avoidance was atypically alternated by 90 degree turns, which may serve as a mechanism to better track the pre dator or a stealth tactic when more vulnerable animals are present. These results provide experimental evidence that humpback whales can exhibit a strong horizontal avoidance as an initial stage of anti-predator defence, indicating that anti-predator responses may be more graded and mixed than previously recognized. Subject Observation, Weapon & Protection SystemsAS - Acoustics & SonarTS - Technical SciencesDefence ResearchBiologyDefence, Safety and SecurityAnti-predator strategyPredator sound playbacksMulti-sensor tagBehavioural responsesHorizontal avoidanceBaleen whaleHumpback whale To reference this document use: http://resolver.tudelft.nl/uuid:ecc6dcdd-e837-4296-8170-ce122d4087ab DOI https://doi.org/10.3354/meps11231 TNO identifier 524579 Source Marine Ecology Progress Series, 526, 267-282 Bibliographical note Published online: 22 April Document type article Files To receive the publication files, please send an e-mail request to TNO Library.