Female túngara frogs elicit more complex mating signals from males

Sexual selection is responsible for the evolution of costly elaborate male traits. When male displays are dynamic, display strategy is sensitive to contextual cues that alter the relative costs and benefits of producing each signal in a male's repertoire. Because females often prefer more elaborate signals, males often respond to female presence by elaborating their display. When added elaboration increases assessment information or reproductive stimulation, females might benefit by extracting the maximum amount of signal elaboration from males. Thus, we expect that females could exaggerate their presence and cause males to produce even costlier and more attractive signals by exhibiting "elicitation" behaviors. We asked whether female túngara frogs elicit increased call complexity from prospective mates. In túngara frogs, adding complexity increases both attractiveness and predation risk. We found that females exhibit a repertoire of movements that function not in mate acquisition, per se, but in display manipulation, by eliciting increased complexity from calling males. The probability that males add complexity to their display increases when females produce these movements. Thus, females actively influence males to produce riskier signals. Copyright 2011, Oxford University Press.