Vol. 33 (2011)
Yellowstone Ecosystem Report

Sexual Selection of Male Song in Free-Living Sagebrush Crickets, Cyphoderris Strepitans

Geoff D. Ower
Illinois State University
Sandra Steiger
Illinois State University
Kyle J. Caron
Illinois State University
Scott K. Sakaluk
Illinois State University

Published 2011-01-01

Abstract

Measures of lifetime mating success in the sagebrush cricket, Cyphoderris strepitans, have revealed that most males succeed in obtaining only 1 mating, while many males fail to attract a female at all and a small minority mate 2 to 4 times. Relative to their abundance in the population, virgin males have a greater likelihood of obtaining a mating than non-virgin males have of securing additional matings, a phenomenon known as the virgin male mating advantage. Previous studies of sagebrush crickets have focused primarily on determining the proximate mechanisms responsible for the virgin male mating advantage, but little work has been done to identify the factors that influence male attractiveness in the first place. Because song plays a central role in mate attraction, itâs likely that variability in song parameters among males could account for the observed differences in mating success. Song is an energetically costly signal to produce and could serve as an honest indicator of male quality. Consequently, males that are able to invest greater amounts of energy into singing should be more attractive to females. In a previous field season, we recorded and analyzed the songs of virgin and non-virgin males and indeed found some evidence that females prefer males which invest greater energy into calling. In the present study, we synthesized artificial sagebrush cricket songs and directly measured female song preference with an arena playback experiment. Females were shown to consistently prefer song characteristics that would require greater energy expenditure by males. Males that sing with long pulse duration, long train duration, and at an intermediate dominant frequency were found to be highly attractive to females.