Sex differences in alternative reproductive tactics in response to predation risk in tree crickets

1. Alternative reproductive tactics (ARTs) are variable, often discontinuous, behaviours that allow a particular sex to achieve enhanced mating success. Predation risk has been hypothesised to drive the evolution of ARTs, but few empirical studies have examined this. It is unclear whether predators affect fitness of the two sexes directly, by reducing survival, or indirectly, by altering mate-searching.

2. In crickets, mate-search typically involves acoustic signalling by males and acoustic-mediated movement towards males by silent females. Males and females may however employ ARTs, which includes silent searching by males, and mating without performing phonotaxis in females.

3. We empirically examined effects of increased predation risk on mate-searching behaviour and survival of male and female tree crickets, and their effects on mating success, using field-enclosure experiments with tree crickets Oecanthus henryi and their primary predator, green lynx spiders, Peucetia viridans...