Variation in the advertisement call of the poison frog Andinobates bombetes relates to geographic distance between populations, but not to divergence in warning coloration

Abstract

ABSTRACT Studying intraspecific geographic variation in communication signals represents a good approach to understand the evolution of species diversification in animals. The poison frog Andinobates bombetes (Dendrobatidae) exhibits intraspecific geographic variation in the spectral traits of its advertisement call. However, it is still unknown whether there is concomitant variation in temporal call traits, and whether call variation is somehow linked to differences in warning coloration (red and yellow morphs). We analyzed spectral and temporal traits of the advertisement calls recorded from 100 males belonging to twelve populations of A. bombetes: nine bearing the red coloration, and three bearing the yellow one. After controlling for eventual effects of temperature and body size of males in call traits, we found geographic variation in both spectral and temporal call traits, yet such variation was unrelated to differences in warning coloration between populations. Previous research indicated that geographic variation in the spectral properties of this species advertisement call can be explained by concomitant differences in the acoustic abiotic environment. Nonetheless, a positive relationship between geographic distance and call divergence also supports the role of genetic drift in the evolution of acoustic signaling of A. bombetes.