Behavioral attributes influence annual mating success more than morphological traits in male collared lizards

Abstract

Traits that potentially influence mating success (MS) may be “static” with low lability once they develop or “dynamic” with highly modifiable expression. We used principal components (PCs) analyses of dynamic behavioral and morphological traits that are static over the short term to determine their relative contributions to the ability of territorial male collared lizards to acquire access to females and obtain high MS. We estimated annual MS of males as the relative frequency with which they engaged in courtship with reproductively active resident females. Three PCs explained statistically significant phenotypic variation among males. Morphological traits loaded significantly on 2 PCs that explained 26.3% and 13.0% of the variance, respectively, whereas behavioral variables loaded significantly on a different component that explained 15.7% of the variance in male traits. The frequency with which males initiated aggressive encounters with same-sex competitors did not load significantly on these PC axes. Males having behavioral PC scores above the mean had significantly higher MS than those with behavioral scores below the mean, whereas male MS was not related to component scores for either of the axes describing static morphological variables. Results indicate that in our population behavior patterns associated with advertisement, particularly to females, influence male MS more strongly than morphological traits or the initiation of direct aggression with same-sex competitors.