Meeting Abstract
Female-specific reproductive coloration is extensive across lizard species, prompting exploration into the potential functions and costs of such traits. Females entering vitellogenesis may produce coloration for signaling aspects of fertility and self-maintenance while affording the costs of reproduction. Exhibiting conspicuous signals could incite male–male competition and perhaps lead to greater sperm competition. Changes in color signals may alternatively deter male attention when females are gravid with eggs or embryos, and thus reduce female costs of reproduction. Using free-living female common side-blotched lizards (Uta stansburiana) as a study species, we compared aspects of innate immunity and oxidative stress across vitellogenic stages to determine potential cost differences throughout reproduction. We also compared orange-throat coloration across vitellogenic stages to determine any differences in signaling for reproductive state. Within vitellogenic stages, we investigated relationships between orange-throat coloration and physiological metrics including innate immunity, oxidative stress, and follicle development. At the onset of vitellogenesis, females have significantly greater oxidative stress than those in late-gravid stages. During gravidity, females exhibit significantly greater antioxidant capacity and a significant decrease in innate immunity. Orange-throat coloration is not correlated with any physiological metrics across vitellogenic stages, but is instead positively correlated with follicle development and innate immunity in females at the height of reproductive investment. These data suggest that female U. stansburiana honestly signal fertility and self-maintenance when they are affording the costs of mid-vitellogenic investment. Further, this reproductive time-point may be a critical period during vitellogenesis for females to attract males for fertilization.
