Castro, J., Cid, A., Martins, M. P., Estrela, G., Pieters, A., and Quirin, A. (2026). Insights Into a Disruptive Behavior of Iberian Killer Whales (𝘖𝘳𝘤𝘪𝘯𝘶𝘴 𝘰𝘳𝘤𝘢) With Boats: Perspective From Multiple Interactions With a Research Vessel. Marine Mammal Science 42, no. 4: e70247. https://doi.org/10.1111/mms.70247
Why do some orcas interact with boats? Our recent scientific publication, published in Marine Mammal Science, contributes to understanding these behaviours through seven episodes of physical contact with our research vessel, recorded between 2018 and 2025 in Algarve region, southern Portugal.
Of the 26 orcas identified during these encounters, 8 made direct contact with the boat, most of them juveniles. Underwater footage revealed a range of behaviours, from gentle touches to pushes strong enough to turn or tilt the vessel, showing that these interactions can vary in both form and intensity.
One of the records dates back to 2018, two years before these behaviours began to be widely reported. The study also provides evidence suggesting social learning: some animals observed during earlier encounters without touching the boat were later seen making physical contact.
“Our observations show just how variable these interactions are. We’ve observed behaviours ranging from curiosity to much more forceful interactions, and even intriguing behaviours such as approaching the vessel with prey in their mouths and apparently showing it to us. The challenge now is to understand what is driving these behaviours and how we can safely coexist with these animals.” explains AIMM’s President and Researcher Dr Joana Castro.
The motivations remain unclear. Curiosity, play and responses to disturbance are possible explanations for different episodes, but the data do not allow us to identify a single cause. As the study is based on a small number of encounters involving a rigid inflatable boat, our team urges caution when generalising the findings.
Understanding these interactions is essential to supporting the conservation of Iberian orcas,a subpopulation classified as Critically Endangered.
The AIMM team will continue to contribute to this knowledge through research and by sharing its findings.
Read our scientific paper and the full interview in Science.
