Female choice and male aggression in the polymorphic lizard Sceloporus minor

Abstract

In comparison with some other vertebrate groups, female choice in lizards is relatively poorly understood. In contrast, aggressive behavior in lizards has been better studied; nevertheless, there are many genera and even whole families for which little or no information on aggressive behavior has been described. Therefore, the objective of this study was to experimentally evaluate the importance of morphometric traits, body coloration, and behavioral attributes of male Sceloporus minor from a population in central Mexico in order to (1) determine whether female choice exists in this species, and if so, identify which features of males females are using to do so, and (2) identify the phenotypic features of males that predict dominance status in contests between dominant and subordinate males. We found that females of S. minor indeed show a preference for males on the basis of ventral patch color; specifically, females chose males with ventral patches of Spectrum Blue or True Blue over males with ventral patches of other blue hues, but found no evidence of choice based on other morphological characters examined. Results also showed that winner (i.e., dominant) males exhibited more aggressive behaviors and were larger in body size than subordinate (i.e., loser) males. Notably, we found no support for a role of male polymorphic dorsal coloration on either female choice or male contest outcome. The results of this study showed evidence of female choice and male-male competition, suggesting that in this population, males exhibit intrasexual interactions to compete for resources such as territories and produce displays that serve in part to attract females.