Document Type

Article

Publication Title

Ecology and Evolution

Publication Date

9-2-2013

Keywords

Communication, fitness surface, mate choice, selection gradient, signal

Abstract

While a number of studies have measured multivariate sexual selection actingon sexual signals in wild populations, few have confirmed these findings withexperimental manipulation. Sagebrush crickets are ideally suited to such investi-gations because mating imposes an unambiguous phenotypic marker on malesarising from nuptial feeding by females. We quantified sexual selection operat-ing on male song by recording songs of virgin and mated males captured fromthree wild populations. To determine the extent to which selection on malesong is influenced by female preference, we conducted a companion study inwhich we synthesized male songs and broadcast them to females in choicetrials. Multivariate selection analysis revealed a saddle-shaped fitness surface,the highest peak of which corresponded to longer train and pulse durations,and longer intertrain intervals. Longer trains and pulses likely promote greatermate attraction, but selection for longer intertrain durations suggests that ener-getic constraints may necessitate “time outs”. Playback trials confirmed theselection for longer train and pulse durations, and revealed significant stabiliz-ing selection on dominant frequency, suggesting that the female auditory sys-tem is tightly tuned to the species-specific call frequency. Collectively, ourresults revealed a complex pattern of multivariate nonlinear selection character-ized primarily by strong stabilizing and disruptive selection on male song traits.IntroductionMale acoustic signals play an important role in mateattraction in a number of taxa including birds (Catchpoleand Slater 1995), mammals (McComb 1991), anurans(Gerhardt and Brooks 2009), and insects (Alexander1962; Huber et al. 1989; Robinson and Hall 2002), andare a frequent target of sexual selection (Andersson 1994).Acoustic signaling can impose high energetic costs onmales (Prestwich and Walker 1981; Bailey et al. 1993;Hoback and Wagner 1997; Hack 1998), and thus songmay also serve as an honest indicator of male quality(Zahavi 1975; Burk 1988). Males that are able to gainaccess to and efficiently convert resources into attractive3590 ª 2013 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.This is an open access article under the terms of the Creative Commons Attribution License, which permits use,distribution and reproduction in any medium, provided the original work is properly cited.

Funding Source

This research was funded by grants from the National Science Foundation to S. K. S.(IOS-0718140 and IOS-1118160) including Research Experiences for Undergraduates, Research Experiences for Teachers, and Research Associate supplemental awards, a Royal Society University Fellowship and NERC grants to J. H., a Feodor Lynen Fellowship from the Alexander von Humboldt Foundation to S. S., and a grant from the Beta Lambda Chapter of Phi Sigma to G. D. O

Comments

First published in Ecology and Evolution (2013): https://doi.org/10.1002/ece3.736

This is an open access article distributed under the terms of the Creative Commons CC BY license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

DOI

10.1002/ece3.736

Share

COinS