Sexual selection and personality: Individual and group-level effects on mating behavior in red junglefowl
Roth AM., Dingemanse NJ., Nakagawa S., McDonald GC., Løvlie H., Robledo-Ruiz DA., PIZZARI T.
1. Despite increasing evidence of the importance of repeatable among-individual differences in behavior (animal personality) in ecology and evolution, little remains known about the role of animal personalities in sexual selection. 2. Here, we present an investigation of the hypothesis that the personalities of individuals and their sexual partners play a role in different episodes of sexual selection, and the extent to which these effects are modulated by the social environment. 3. We first examined how two repeatable behaviors – exploration and boldness – are associated with pre- and postcopulatory sexual selection, with a focus on the former, in male red junglefowl, Gallus gallus, using replicate groups across three experimental sex ratio treatments. We further explored how the social environment modulates relationships between male personality and mating performance, and whether mating is assortative or disassortative with respect to exploration or boldness. Lastly, we examined behavioral mechanisms linking personality with mating performance. 4. Across all sex ratios, the fastest- and slowest-exploring males harassed females proportionally less, and faster-exploring males associated with females more and received more sexual solicitations. In female-biased groups, the fastest- and slowest-exploring males experienced the highest mating success and lowest sperm competition intensity. Faster-exploring males also obtained more mates in female-biased groups when their competitors were, on average, slower-exploring, and the proportion of matings obtained by fast-exploring males decreased with the proportion of fast-exploring males in a group, consistent with negative frequency-dependent sexual selection. While boldness did not predict mating performance, there was a tendency for individuals to mate disassortatively with respect to boldness. 5. Collectively, our results suggest that male exploration can play a role in sexual selection, and that sexual selection on personality is complex and contingent on the social environment.