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

Males that produce conspicuous mating signals may attract competitors in addition to sexually receptive females. In many species, for example, females use male calls to locate and choose mates and males respond to competitors' signals by modulating signal production or changing location, thereby escalating or decreasing competition. Do these different receivers make decisions using male signals in the same way? We compared how male and female field crickets (Gryllus integer) made decisions to approach 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 with short bouts. When presented with calls in isolation, however, only females preferred long-bout calls. Females thus appear to use an internal standard to evaluate calls, whereas males apparently compare the relative attractiveness of alternatives. We also found that males assess calls in relation to their own competitive potential by testing 2 hypotheses that make different predictions regarding variation in male responses to competitor signals. We found no support for the satellite male hypothesis, as unattractive males did not preferentially approach female-preferred calls; in support of the aggressive displacement hypothesis, males likely to win contests preferentially approached the female-preferred call. Our work demonstrates that even though the sexes process the same information, different mechanisms of reproductive success (mate location vs. mate attraction) can result in sex differences in the perception and use of conspecifics' signals. Copyright 2009, Oxford University Press.