Simulation of alternative male reproductive behavior: calling and satellite behavior in field crickets

Abstract

Male field crickets and other acoustically communicating insects call and attract females and silently intercept females attracted by the calling of other males, so-called satellite behavior. A simulation of field cricket, Gryllus integer, mating behavior suggests that population density and sex ratio changes during the breeding season are important factors determining mating success of calling and satellite males. Satellite mating success increased with the proportion of satellite males, but mating success of callers was independent of the proportion of calling males. Satellite male mating success was greatest in high density populations with extremely female-biased sex ratios. Calling males also mated more often under most population densities, various populations differing in the proportion of callers and in sex ratios. Calling male mating advantage decayed exponentially, however, with increasing population density. Variation in male G. integer reproductive behavior has previously been associated with fluctuating population densities in empirical studies on laboratory and field populations. The simulation suggests that variation in male mating success with the operational sex ratio also contributes to the continuing existence of alternative male reproductive behavior. Predictions derived from the simulation can be tested in actual populations of G. integer and other species.