Stochastic Influences, Female Copying and the Intensity of Sexual Selection on Leks

It is widely agreed that female copying of each othersʹ movements or mate choices on leks (clusters of male mating territories) may increase the intensity of sexual selection. We present computer simulations of female choice on ungulate leks which explore how female copying and stochastic influences on female movement may interact to influence the intensity of sexual selection on males. Where stochastic influences were weak or absent, copying was found to increase selection pressures, but where stochastic events sporadically redistributed females, copying could decrease the intensity of selection. These results suggest that non-independent female movements on leks may not always increase the intensity of selection and that caution should be exercised before assuming that such non-independent movements are adaptive mechanisms of female mate choice.