Testing for a whole-organism trade-off between natural and sexual selection: are the male guppies preferred by females more likely to be eaten by predators?

Background: Trade-offs between natural and sexual selection have major consequences for the evolution of traits subject to both forces. However, such a trade-off might not be easily detected given that both natural and sexual selection operate in a multi-trait - rather than in a single-trait - manner. Organism: The Trinidadian guppy, Poecilia reticulata (Osteichthyes). Hypothesis: Males preferred by females are more susceptible to predation. Aim: Develop and apply a whole-organism, performance-based test for a trade-off between natural and sexual selection. Methods: We conducted three different experiments involving pairs of males in female choice trials followed by the same pairs of males in predation trials. The hypothesis was tested with chi-square contingency table analyses for each experiment separately and for all data combined. Results: Males preferred by females were not more likely to be eaten by a predator. Conclusion: The whole-organism, performance-based trade-off is absent, very weak, or context-dependent, making it difficult to detect in experiments.