Social and genetic connectivity despite ecological variation in a killer whale network

Philopatric kin-based societies encourage a narrow breadth of conservative behaviours owing to individuals primarily learning from close kin, promoting behavioural homogeneity. However, weaker social ties beyond kin, and across a behaviourally diverse social landscape, could be sufficient to induce...

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Bibliographic Details
Published in:Proceedings of the Royal Society B: Biological Sciences
Main Authors: Jourdain, Eve, Karoliussen, Richard, Fordyce Martin, Sarah L., Langangen, Øystein, Robeck, Todd, Borgå, Katrine, Ruus, Anders, Foote, Andrew D.
Other Authors: H2020 European Research Council, Norges Forskningsråd, Sea World & Busch Gardens Conservation Fund
Format: Article in Journal/Newspaper
Language:English
Published: The Royal Society 2024
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Online Access:http://dx.doi.org/10.1098/rspb.2024.0524
https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2024.0524
https://royalsocietypublishing.org/doi/full-xml/10.1098/rspb.2024.0524
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Summary:Philopatric kin-based societies encourage a narrow breadth of conservative behaviours owing to individuals primarily learning from close kin, promoting behavioural homogeneity. However, weaker social ties beyond kin, and across a behaviourally diverse social landscape, could be sufficient to induce variation and a greater ecological niche breadth. We investigated a network of 457 photo-identified killer whales from Norway (548 encounters in 2008–2021) with diet data available (46 mixed-diet individuals feeding on both fish and mammals, and 411 exclusive fish-eaters) to quantify patterns of association within and between diet groups, and to identify underlying correlates. We genotyped a subset of 106 whales to assess patterns of genetic differentiation. Our results suggested kinship as main driver of social bonds within and among cohesive social units, while diet was most likely a consequence reflective of cultural diffusion, rather than a driver. Flexible associations within and between ecologically diverse social units led to a highly connected network, reducing social and genetic differentiation between diet groups. Our study points to a role of social connectivity, in combination with individual behavioural variation, in influencing population ecology in killer whales.