Honest signals and sexual conflict: Female lizards carry undesirable indicators of quality |
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Authors: | Braulio A Assis Julian D Avery Catherine Tylan Heather I Engler Ryan L Earley Tracy Langkilde |
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Institution: | 1. Department of Biology, The Pennsylvania State University, University Park PA, USA ; 2. Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park PA, USA ; 3. The Department of Ecosystem Science and Management, The Pennsylvania State University, University Park PA, USA ; 4. Department of Biological Sciences, University of Alabama, Tuscaloosa AL, USA |
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Abstract: | Sex differences in animal coloration often result from sex‐dependent regulatory mechanisms. Still, some species exhibit incomplete sexual dimorphism as females carry a rudimentary version of a costly male trait, leading to intralocus sexual conflict. The underlying physiology and condition dependence of these traits can inform why such conflicts remain unresolved. In eastern fence lizards (Sceloporus undulatus), blue iridophore badges are found in males and females, but melanin pigmentation underneath and surrounding badges is male‐exclusive. We track color saturation and area of badges across sexual maturity, and their relationship to individual quality (body condition and immunocompetence) and relevant hormones (testosterone and corticosterone). Saturation and testosterone were positively correlated in both sexes, but hormone and trait had little overlap between males and females. Saturation was correlated with body condition and immunocompetence in males but not in females. Co‐regulation by androgens may have released females from resource allocation costs of color saturation, even when in high condition. Badge area was independent of testosterone, but associated with low corticosterone in females, indicating that a nonsex hormone underlies incomplete sexual dimorphism. Given the evidence in this species for female reproductive costs associated with ornamentation, this sex‐nonspecific regulation of an honest signal may underlie intralocus sexual conflict. |
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Keywords: | color condition dependence female ornamentation honesty mechanism intralocus sexual conflict Sceloporus sexual antagonism |
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