Female mate attraction in ornate tree lizards, Urosaurus ornatus: a multivariate analysis

Recent reviews of mate choice have concluded that this phenomenon is rare or nonexistent in lizards. However, direct tests of lizard mate choice are few and generally limited in scope. We present results of a mate choice experiment with Urosaurus ornatus in which two male lizards differing in morphology, colour and behaviour were given the opportunity to attract a female lizard. Pairwise comparisons of selected and unselected males revealed that variation in individual traits failed to account for much of the variation in mate attraction success. However, a multivariate analysis revealed that mate attraction was related to multiple cues from a male's phenotype: body mass and head size as well as body and tail coloration all contributed to mate attraction. We argue that the additive and interactive effects of several traits combined may be more important than single traits in mate choice. We suggest that mate choice studies should account for multivariate effects of male traits, and also allow mate attraction to occur over variable spatial and temporal scales, paralleling mate choice under natural conditions.