The predation cost of female resistance

Mating costs to females can result in female reluctance to mate and the evolution of seemingly costly rejection strategies. The costs of mating have been widely studied; however, the costs of resistance have rarely been quantified. In the Lake Eyre dragon, Ctenophorus maculosus, gravid females flip over onto their backs to prevent superfluous matings. In doing so, they compromise their camouflage as females have bright orange ventral coloration during the breeding season. Visual models confirmed that resisting females are much more conspicuous to birds, their primary predator, than unresisting females. We assessed the predation risk of female resistance via a large-scale field experiment using model female lizards. Although the flipped over, orange models were more conspicuous to visual predators, they were attacked significantly less than cryptic models. It appears that predators avoid the bright females, possibly because they do not recognize orange individuals as food or avoid rare, conspicuously colored prey. Thus, conspicuous female rejection displays may be maintained in part by apostatic selection, in which predators form a search image for and preferentially attack more common prey types. Copyright 2010, Oxford University Press.