The components of female choice in relation to diet and plasma carotenoid levels. (a) Mean ± s.e. mate responsiveness of high- and low-carotenoid females. (b) Scatterplot illustrating the relationship between female mate discrimination and plasma carotenoid levels prior to carotenoid supplementation. (c) Scatterplot showing the female preference functions and plasma carotenoid levels prior to carotenoid supplementation. Open symbols represent the low-carotenoid females and closed symbols represent the high-carotenoid females.