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In many species of lizards, males fight over territories that allow them access to females, and during these interactions males will display sexual signals to competing individuals. Social signals such as coloration, are seemingly favored by sexual selection as they are thought to provide information about individual quality, such as performance capacity. Side-blotched Lizards, Uta stansburiana, exhibit throat color polymorphism (i.e. orange, yellow, and blue badges), which signal alternative life history strategies to conspecifics. Although morphological, behavioral and physiological characteristics have been shown to differ across male morphs, color variation within each morph has not been compared to aspects of individual quality. In wildcaught adult male U. stansburiana, we tested for associations between coloration (colorimetrics and size of throat badge and side-blotch), a range of morphological traits (snout–vent length, mass, limb and head measures), and performance capacity (sprint speed). Across morphs, sprint speed is positively correlated with aspects of coloration including throat badge and side-blotch size. Sprint speed is also positively correlated with mass, but not snout-vent length and hind limb length. Within morphs, blue hue, yellow brightness, and orange saturation are positively correlated with sprint speed, while other colorimetric relationships are not significant. Our results reveal sexual coloration in male U. stansburiana to be indicative of performance capacity, which may be used as competitive signals under sexual selection.

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