Male mating preference in sticklebacks: Effects of repeated testing and own attractiveness

In sticklebacks, Gasterosteus aculeatus, males have conspicuous nuptial coloration, whereas females are cryptically coloured. Usually females are the choosy sex in mate choice, but under certain conditions males may be choosy too. Females signal their spawning readiness, among others, by displaying a head-up courtship posture while pointing at the preferred male. We tested the male's preference for this posture by offering males a simultaneous choice of two stylized dummies of ripe females, one in head-up posture and one horizontal. The males directed relatively more courtship to the head-up dummy, and tended to do the more so the more intense the blue iris of their own eyes (corrected for differences in male length). Because the blue eye colour is a criterion of female choice in this population, attractive males tended to be choosier. Upon repeated presentation of the dummies to the same males on subsequent days, the males' preference for the head-up dummy disappeared, but there was no change in total courtship activity. When confronted with a different, more realistic pair of dummies, the same males showed again a preference for the head-up posture suggesting that male preference can be influenced by experience.