Garrulous Gallus gets the girl: production of high-risk alarm calls is the best predictor of male mating success in fowl.

Studies of mate choice in fowl typically invoke ornament size as the best predictor of male mating success. In these studies, a hen is presented with two unfamiliar and physically separated males that she can evaluate and mate with for up to 90 minutes. This design controls for prior experience and male-male competition, but deprives females of information available only from longer sampling periods and a more natural context. In the wild, fowl spend their lives in stable social groups. We observed birds under naturalistic conditions to evaluate the biological significance of ornament size and to explore other potential predictors of male mating success. For each male, we measured morphology and several behaviours related to food predators, dominance and courtship. Using PCA and multiple regression, we show that behavior is the best predictor of male mating success under natural conditions, and that the most salient behaviours are dominance and the rate of antipredator signalling. Dominance probably affects mating by determining access to females, but the mechanism responsible for the role of alarm calling is less clear. Alarm signals may advertise male quality, or they may reflect judicious risk-taking by males that have likely achieved paternity.