Movements and site fidelity of killer whales (Orcinus orca) relative to seasonal and long-term shifts in herring (Clupea harengus) distribution

• Published in: Marine Biology
• Main Authors: Samarra, Filipa I. P., Tavares, S. B., Béesau, J., Deecke, V. B., Fennell, A., Miller, P. J. O., Pétursson, H., Sigurjónsson, J., Víkingsson, G. A.
• Other Authors: Office of Naval Research, University of St Andrews. Sea Mammal Research Unit, University of St Andrews. School of Biology, University of St Andrews. Marine Alliance for Science & Technology Scotland, University of St Andrews. Scottish Oceans Institute, University of St Andrews. Institute of Behavioural and Neural Sciences, University of St Andrews. Centre for Social Learning & Cognitive Evolution, University of St Andrews. Bioacoustics group
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: Movements; Distribution shifts; Photo-identification; Predator-prey relationship; Prey specialisation; QH301 Biology; SH Aquaculture. Fisheries. Angling; Aquatic Science; Ecology; Evolution; Behavior and Systematics; NDAS; QH301; SH; Iceland; Orca; Orcinus orca
• Online Access: http://hdl.handle.net/10023/15081; https://doi.org/10.1007/s00227-017-3187-9

Funding was provided by a Fundação para a Ciência e a Tecnologia doctoral scholarship (Grant No. SFRH/BD/30303/2006), an Icelandic Research Fund (i. Rannsóknasjóður) START Postdoctoral Fellowship (Grant No. 120248042), the National Geographic Society Science and Exploration Europe (Grant No. GEFNE65-12) and a Russell Trust Award (University of St. Andrews) to FIPS, the Office of Naval Research (Grant No. N00014-08-10984) to PJOM, a Fundação para a Ciência e a Tecnologia doctoral scholarship (Grant No. SFRH/BD/84714/2012) to SBT and support from the BBC Natural History Unit and funding from a Full Doctorate Fellowship from CNPq/Capes through the Science Without Borders Program, Marie-Curie Intra-European Fellowship and Research and Scholarship Development Fund (University of Cumbria) to VBD. Predators specialising on migratory prey that frequently change migration route face the challenge of finding prey with an unpredictable distribution. Here, we used photo-identification data to investigate whether killer whales observed in herring overwintering and spawning grounds off Iceland follow herring year-round, as previously proposed, and have the ability to adapt to long-term changes in herring distribution. Of 327 identified whales seen more than once, 45% were seen in both grounds, and were thus presumed herring-specialists, likely following herring year-round, while others were only seen on one of the grounds, possibly following herring to unsampled grounds or moving to other locations and exploiting different prey. High seasonal site fidelity to herring grounds, long-term site fidelity to herring spawning grounds, and matches of individual whales between past and recently occupied herring overwintering grounds showed an ability to adapt to long-term changes in prey distribution as well as diversity of movement patterns which are maintained over time, likely as socially-learnt traditions. Such population structuring shows that the movement patterns and foraging ecology of herring-eating killer whales are more ...