From forest to city: Urbanization modulates relative abundance of anti-predator coloration

Increased urbanization has resulted in community changes including alteration of predator communities. Little is known, however, about how such changes affect morphological anti-predator traits. Given the importance of coloration in predator avoidance, this trait in particular is expected to be susceptible to novel selective environments in urban areas. Here we investigate the coloration pattern of a Neotropical anuran species, the túngara frog (Engystomops pustulosus), along an urbanization gradient. Túngara frogs have two distinct color patterns (unstriped and striped) which we found to occur at different frequencies along an urbanization gradient. Striped individuals increased in frequency with urbanization. To assess the strength of selection imposed by predators on the two color morphs, we deployed clay models of túngara frogs in forest and semi-urban populations. In addition, we examined microhabitat selection by individuals of the different morphs. We found higher predation rates...