Signal components, acoustic preference functions and sexual selection in a cricket

Abstract

In many sexually reproducing organisms, females choose mates based on multiple male traits. This study examined how two temporal components of the male mating call - chirp rate and chirp duration - affect female mating preference in five populations of a widely distributed North American cricket, Allonemobius socius (Orthoptera, Gryllidae). Chirp rate and chirp duration of the A. socius mating call were varied independently, and the responses of virgin females to these experimentally manipulated calls were repeatedly measured using a sequential single-stimulus design. Significant among- and within-population variation in chirp-duration preferences of females were found. Contrary to many previous studies, call chirp rate had no effect on female phonotaxis. Also there was no evidence of an interaction between chirp rate and chirp duration on female response to male mating calls. Moreover, female responsiveness to average and above-average chirp duration appeared to decline with female (adult) age. Overall, these results suggest evolved differences among populations in chirp-duration preferences, and that selection can act within populations on female chirp-duration preference. © 2004 The Linnean Society of London.