Experimentally induced innovations lead to persistent culture via conformity in wild birds.

Bibliographic Collection: 
Publication Type: Journal Article
Authors: Aplin, Lucy M; Farine, Damien R; Morand-Ferron, Julie; Cockburn, Andrew; Thornton, Alex; Sheldon, Ben C
Year of Publication: 2015
Journal: Nature
Volume: 518
Issue: 7540
Pagination: 538-41
Date Published: 2015 Feb 26
Publication Language: eng
ISSN: 1476-4687
Keywords: Animals, Animals, Wild, Birds, Cultural Evolution, Diffusion of Innovation, Feeding Behavior, Female, Great Britain, Learning, Male, Social Conformity, Time Factors

In human societies, cultural norms arise when behaviours are transmitted through social networks via high-fidelity social learning. However, a paucity of experimental studies has meant that there is no comparable understanding of the process by which socially transmitted behaviours might spread and persist in animal populations. Here we show experimental evidence of the establishment of foraging traditions in a wild bird population. We introduced alternative novel foraging techniques into replicated wild sub-populations of great tits (Parus major) and used automated tracking to map the diffusion, establishment and long-term persistence of the seeded innovations. Furthermore, we used social network analysis to examine the social factors that influenced diffusion dynamics. From only two trained birds in each sub-population, the information spread rapidly through social network ties, to reach an average of 75% of individuals, with a total of 414 knowledgeable individuals performing 57,909 solutions over all replicates. The sub-populations were heavily biased towards using the technique that was originally introduced, resulting in established local traditions that were stable over two generations, despite a high population turnover. Finally, we demonstrate a strong effect of social conformity, with individuals disproportionately adopting the most frequent local variant when first acquiring an innovation, and continuing to favour social information over personal information. Cultural conformity is thought to be a key factor in the evolution of complex culture in humans. In providing the first experimental demonstration of conformity in a wild non-primate, and of cultural norms in foraging techniques in any wild animal, our results suggest a much broader taxonomic occurrence of such an apparently complex cultural behaviour.

DOI: 10.1038/nature13998
Alternate Journal: Nature