Repeatability: Its role in evolutionary studies of mating behavior

Summary

Repeatability, a concept derived from quantitative genetics theory, is a statistic that describes the degree to which variation within individuals contributes to total variation in a population. Its usual application has been to set an upper limit on heritability but it may also be useful for studies of stereotypy of behavior. The repeatability of the production of male mating signals gives information both about whether males differ sufficiently for selection to act and whether the differences could be appreciably heritable. Measures of the repeatability of female mating preferences will provide data that can describe the preference functions used in mathematical models of the evolution of sexually selected traits, as well as putting an upper bound on the heritability of preferences. A survey of the few measures in the literature shows that the repeatability of male signal production varies substantially (range 0.21–0.85) and does not necessarily reflect heritability. The repeatabilities of female preferences have not been published previously: for the response to conspecific pheromones by female flour beetles (Tribolium castaneum), my best estimate is zero. Measuring the repeatability of other traits such as parental care and foraging behavior may also lead to insights about selection on and the evolution of these traits.