Noise from Urban Environments Affects the Color of Songbirds’ Beaks

A study examined the effects of anthropogenic noise on cognition, beak color, and growth in the zebra finch. Researchers first tested adult zebra finches on a battery of cognition assays while they were exposed to playbacks of urban noise versus birds tested without noise. Urban noises caused the birds to take longer to learn a novel foraging task and to learn an association-learning task. Urban noise exposure also resulted in treated males to develop less bright beak coloration, and females developed beaks with brighter orange coloration, respectively, than untreated birds. Findings suggest that urban noise exposure may affect morphological traits, such as beak color, which influence social interactions and mate choice.