Exploitation of sexual signals by predators or parasites increases costs to signalers, creating opportunities for establishment of alternative reproductive tactics (ARTs). In field crickets, males calling may attract acoustically orienting parasitoid flies. Alternatively, males behaving as satellites forgo calling and attempt to intercept females attracted to callers. We modeled the contribution of calling versus satellite behavior to male reproductive success in the larger context of variation in ecology (parasitism rate, background mortality), demography (density, sex ratio), and female behavior (phonotaxis, mating choosiness). Male mating success was most influenced by number of females (standardized effect size 0.42), followed by female choosiness (0.33), background mortality (20.31), number of males (20.28), and parasitism rate (20.21). The smallest effects were phonotaxis (0.10) and satellite behavior (20.09). Although satellite behavior ameliorated negative effects of parasitism, its comparative effect was slight. ARTs seem most likely to evolve and persist when a single selection pressure on signaling is particularly strong.
Bibliographical noteFunding Information:
We thank E. Swanger for her contributions to the original development of the simulation model and members of the University of Minnesota Behavior Group for thoughtful comments on this research. Helpful suggestions from S. Bertram and an anonymous reviewer improved the manuscript. This work was supported by National Science Foundation Integrative Organismal Systems grants to M.Z. and by the University of Minnesota.
- Alternative reproductive tactics
- Ecological context
- Field crickets
- Individual-based simulation
- Satellite behavior