Prey of killer whales (Orcinus orca) in Iceland

• Published in: PLOS ONE
• Main Authors: Samarra, Filipa, Bassoi, Manuela, Béesau, Julie, Elíasdóttir, Margrét Ó., Gunnarsson, Karl, Mrusczok, Marie-Thérèse, Rasmussen, Marianne, Rempel, Jonathan N., Þorvaldsson, Baldur, Víkingsson, Gísli
• Other Authors: Rannsóknasetur á Húsavík (HÍ), Research Centre in Húsavík (UI), Háskóli Íslands, University of Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2018
• Subjects: Killer whales; Predation; Minke whales; Seals; Iceland; Pilot whales; Marine mammals; Porpoises; Háhyrningur; Ránlífi; Hrefna; Selir; Grindhvalur; Sjávarspendýr; Hauganes; Moe; Killer Whale; Orca; Orcinus orca; Killer whale
• Online Access: https://hdl.handle.net/20.500.11815/1095; https://doi.org/10.1371/journal.pone.0207287

Publisher's version (útgefin grein) Killer whales have a cosmopolitan distribution and as a species are generalists, feeding on a variety of prey. However, local populations tend to specialise on specific prey types. In Icelandic waters, killer whales are generally associated with herring and, thus, have been presumed to be herring specialists. However, recent studies suggest a more complex foraging ecology, possibly including a mosaic of strategies. With increased observational effort in recent years due to research and whale-watching activities, there have been several reports of interactions with different prey, including confirmed predation events. In this study we aimed to summarise the range of potential prey of killer whales observed in Icelandic waters. We report on 12 previously unpublished accounts and review 15 accounts published in the scientific literature or local newspapers, making a total of 27 events where killer whales were observed interacting with actual or potential prey. Thirteen different species, including birds (n = 1), cephalopods (n = 1), fish (n = 5) and marine mammals (n = 6), are reported, although herring is by far the species that killer whales are most often observed interacting with. This study provides the first summary of actual and suspected killer whale prey in Icelandic waters, and contributes towards our understanding of this population’s prey preferences. However, describing the diet of individuals/groups was not possible and this study points to a need for continued monitoring to understand the intricacies of killer whale foraging behaviour in this area. MB was employed by Elding Whale Watching, MOE was employed by Whales Hauganes ehf., MTM was employed by Láki Tours, JNR was employed by Special Tours and BT was employed by Iceland Pro Cruises. The funders provided support in the form of salaries for authors and in all cases (except Iceland Pro Cruises) provided platforms from where observations were made, but did not have any additional role in the study design, ...