The effect of male dominance on female choice in a field cricket (Gryllus assimilis)

Abstract

Theory suggests that behaviours previously thought only to influence intrasexual selection, such as aggression between males, can also be co-opted to serve in intersexual selection as honest indicators of male quality. Our previous research revealed an audience effect: male Jamaican field crickets, Gryllus assimilis, fight more aggressively in front of a female audience. One way for this to evolve is if females are more attracted to more aggressive males or fight winners. Given the potential interplay between intra- and intersexual selection, we investigated how observing a fight influences subsequent female mate choice and mating behaviour. We utilized two female treatments: Observers watched the two males fight, whereas Non-observers watched two noninteracting males. We then immediately tested Observer and Non-observer females for their mating preferences towards male fight participants using dichotomous and no-choice tests. Our approach enabled us to assess whether females preferred either dominant (winner) or subordinate (loser) males and whether females gathered information about males while watching them fight that informed their mating preferences. While females did not prefer fight winners over losers in dichotomous choice tests, in the no-choice tests, females were more likely to mount winners and mount males that they had preferred in the dichotomous choice tests. Intra- and intersexual competition appears to be mutually reinforcing in this species, but eavesdropping is unlikely to explain the evolution of audience effects.