Male and female crickets use different decision rules in response to mating signals

Abstract

Males that produce conspicuous mating signals may attract competitors in addition to sexually receptive females. In manyspecies, for example, females use male calls to locate and choose mates and males respond to competitors’ signals by modulatingsignal production or changing location, thereby escalating or decreasing competition. Do these different receivers make deci-sions using male signals in the same way? We compared how male and female field crickets (Gryllus integer) made decisions toapproach male calls differing in calling bout length, a heritable trait known to play an important role in female mate choice.When offered a simultaneous choice between playbacks, both males and females preferred calls with long bouts to those withshort bouts. When presented with calls in isolation, however, only females preferred long-bout calls. Females thus appear to usean internal standard to evaluate calls, whereas males apparently compare the relative attractiveness of alternatives. We also foundthat males assess calls in relation to their own competitive potential by testing 2 hypotheses that make different predictionsregarding variation in male responses to competitor signals. We found no support for the satellite male hypothesis, as unattractivemales did not preferentially approach female-preferred calls; in support of the aggressive displacement hypothesis, males likely towin contests preferentially approached the female-preferred call. Our work demonstrates that even though the sexes process thesame information, different mechanisms of reproductive success (mate location vs. mate attraction) can result in sex differencesin the perception and use of conspecifics’ signals. Key words: contests, decision rules, Gryllus integer, male phonotaxis, matechoice, satellite males, sexual dimorphism, thresholds. [Behav Ecol]