The Influence of Temperature on Courtship and Mate Choice in a Wolf Spider: Implications for Mating Success in Variable Environments.

Abstract

Selection on animal signal form often changes significantly with the environment, yet signal form may itself be environment dependent. Little is known about how variation in individual responses to changing environments affects the relationship between selection and the subsequent evolution of signal traits. To address this question, we assess the effects of variation in temperature on individual signaling and mating behavior responses across temperatures in the wolf spider Schizocosa floridana. By running repeated-measures trials, we find that temperature has predictable effects on signal form, but that the performance of individual courters is not consistent across temperatures. Traits associated with courtship rate generally increase at higher temperatures but inter-individual consistency in response to temperature change is low, despite consistent female preferences for increased courtship rate at all temperatures. Interestingly, production of the likely most recently evolved signal component, the chirp, is consistent within signalers and predicts male performance across temperatures. Despite this, female preferences for chirp duration appear only at higher temperatures. Taken together, our results suggest that individual courter responses to changing temperatures have the potential to dampen or eliminate patterns of selection that are evident across temperatures. We discuss these results in the light of current research on mating behavior and sexual selection.