Data from: Mating status correlates with dorsal brightness in some but not all poison frog populations

Sexual signals are important for intraspecific communication and mate selection, but their evolution may be driven by both natural and sexual selection, and stochastic processes. Strawberry poison frogs (Oophaga pumilio) show strong color divergence among populations, but coloration also varies among individuals of the same population. The importance of coloration for female mate choice has been studied intensely, and sexual selection seems to affect color divergence in strawberry poison frogs. However, the effect of coloration on mating success under field conditions has received very little attention. Furthermore, few studies examined how phenotypic variation among individuals of the same color morph affects mate selection under natural conditions. We measured the spectral reflectance of courting and noncourting individuals and their background substrates in three geographically separated populations. In one population (Sarapiquí, Costa Rica), we found that naturally occurring courting pairs of males and females had significantly brighter dorsal coloration than individual males and females not engaged in courtship interactions. Our field observations suggest that, in the wild, females prefer brighter males while the reason for the higher courtship activity of brighter females remains unclear. Overall our results imply that brightness differences among individuals of the same color morph may actually affect reproductive success in some populations of strawberry poison frogs.

性信号对于种内交流与配偶选择至关重要，但其演化可能同时受到自然选择、性选择以及随机过程的驱动。草莓箭毒蛙（Oophaga pumilio）不同种群间存在显著的体色分化，而同一种群内的个体间体色也存在差异。学界已对体色在雌性配偶选择中的重要性开展了广泛研究，性选择似乎会影响草莓箭毒蛙的体色分化。然而，野外条件下体色对交配成功率的影响却极少受到关注。此外，鲜有研究探讨自然条件下同一体色型个体间的表型差异如何影响配偶选择。我们在三个地理隔离的种群中，测量了求偶与非求偶个体及其背景基质的光谱反射率。在哥斯达黎加萨拉皮基（Sarapiquí）的一个种群中，我们发现自然形成的雌雄求偶配对个体的背部体色显著亮于未参与求偶行为的雌雄个体。我们的野外观察表明，在自然环境中雌性更偏好体色更亮的雄性，而体色更亮的雌性求偶活跃度更高的原因仍不明晰。综合来看，我们的研究结果表明，在部分草莓箭毒蛙种群中，同一体色型个体间的亮度差异可能确实会影响其繁殖成功率。