The hawk-dove game played between mating partners: theoretical predictions and experimental results

Abstract

Game theoretical models on contest behaviour generally assume that individuals, when competing by pair-wise contests, make their decision to maximize their own rewards. In several situations, however, individuals’ fitness is unlikely to depend solely on their performance, and one would then expect individuals to modify their behaviour towards specific group members. This is the case for instance in monogamous species when an individual competes with its mating partner that contributes as well to the breeding performance of the pair. In this study, we explored whether individuals, when searching for food in the presence of their partner, tend to preferentially interact with them and if pair members behave differently compared to unfamiliar individuals. First, we developed a variant of the hawk-dove game that predicts the frequency and intensity of interactions between pair members, and second, we conducted a laboratory experiment with zebra finches (Taeniopygia guttata) to evaluate the effects of pair bonding on the frequency of aggression and joining events. We found that individuals interacted more frequently with their partner than expected by chance. Thus, although males initiated more aggressive interactions towards their partner than towards any other member of the flock, our findings support our model’s prediction that males would benefit from being tolerant towards their social partner and preferentially interact with her, in order to maximize her foraging success and hence, ultimately, the breeding performance of the pair.