Dynamically honest displays: Courtship locomotor performance indicates survival in guppies

1. The indicator theory of sexual selection suggests that mating displays honestly signal aspects of fitness. While rarely studied, kinematic (locomotor) performance is an excellent candidate for an honest indicator, as mating displays of many animals include rapid or extended locomotion that may be physiologically correlated with performance traits that impact survival. 2. We investigate the indicator value of display locomotion of wild-caught male guppies, Poecilia reticulata, by examining relationships between mating display kinematic traits, anti-predator kinematic traits, and survival during a subsequent staged encounter with a natural predator, the pike cichlid Crenicichla alta. 3. We first compared guppy display kinematics with subsequent survival, and found that display body angle and angular speed positively predicted survival. We next compared anti-predator kinematic and tactical traits with survival, to identify traits that might link mating displays to survival. We measured anti-predator traits in two tests, first in response to a standardized stimulus (fast start test), and second in response to the live predator (encounter test). Guppy fast start speed and encounter speed, time in refuges, and approach distance (response distance) all positively predicted survival, while encounter swim duration negatively predicted survival. These data provided our final hypothesis, that these particular anti-predator traits would be correlated with mating display kinematics. However, we detected only one of eight predicted correlations, a negative relationship between display body angle and encounter swim duration that may reflect an energy trade-off. 4. We conclude that courtship locomotor performance can be an honest survival indicator in guppies, and that the mechanism linking courtship to survival merits further study. These results suggest that courtship locomotion may contribute to viability impacts on the evolution of animal mate choice, and support others in suggesting that these traits may reward greater attention in sexual and natural selection studies