Female social experience affects the shape of sexual selection on males

Abstract

Background: An increasing number of factors have been shown to affect female mating behaviour, and thus to affect the strength and/or direction of selection that females exert on males. One of these factors is female social experience (including mating history). Question: How does female social experience affect the strength and direction of selection on four male traits - age, body size, weaponry size, and body condition? Methods: I used multivariate selection analysis to estimate the linear and non-linear selection gradients exerted by female field crickets (Gryllus pennsylvanicus) with different social backgrounds. Females were either virgins with no experience of conspecifics as adults or experienced females from a large, mixed-sex population. I assessed relative fitness through mating success (mated or not) and calculated selection gradients for the four male traits. Results: Experienced females exerted significant positive directional selection on male weaponry size and favoured older males. However, linear variation in these traits did not affect the probability of an inexperienced female mating. I also detected correlational selection by inexperienced females, who preferred combinations of age and body size (old/large and young/small). © 2010 Kevin A. Judge.