Acoustic adaptation to city noise through vocal learning by a songbird.
Anthropogenic noise imposes novel selection pressures, especially on species that communicate acoustically. Many animals-including insects, frogs, whales and birds-produce sounds at higher frequencies in areas with low-frequency noise pollution. Although there is support for animals changing their vocalizations in real time in response to noise (i.e. immediate flexibility), other evolutionary mechanisms for animals that learn their vocalizations remain largely unexplored. We hypothesize that cultural selection for signal structures less masked by noise is a mechanism of acoustic adaptation to anthropogenic noise. We test this hypothesis by presenting nestling white-crowned sparrows (Zonotrichia leucophyrs) with less-masked (higher-frequency) and more-masked (lower-frequency) tutor songs either during playback of anthropogenic noise (noise-tutored treatment) or at a different time from noise playback (control treatment). As predicted, we find that noise-tutored males learn less-masked songs significantly more often, whereas control males show no copying preference, providing strong experimental support for cultural selection in response to anthropogenic noise. Further, noise-tutored males reproduce songs at higher frequencies than their tutor, indicating a distinct mechanism to increase signal transmission in a noisy environment. Notably, noise-tutored males achieve lower performance songs than their tutors, suggesting potential costs in a sexual selection framework.
['Moseley|Dana Lynn|DL|0000-0001-7627-8955', 'Derryberry|Graham Earnest|GE|0000-0002-0399-1095', 'Phillips|Jennifer Nicole|JN|0000-0002-0014-2995', 'Danner|Julie Elizabeth|JE|', 'Danner|Raymond Michael|RM|0000-0002-3999-8141', 'Luther|David Andrew|DA|0000-0003-3331-6186', 'Derryberry|Elizabeth Perrault|EP|0000-0002-8248-9748']
D000162:Acoustics D000222:Adaptation, Physiological D000818:Animals D002947:Cities D008297:Male D009622:Noise D012495:San Francisco D020308:Songbirds D046370:Sparrows D014828:Vocalization, Animal
anthropogenic noise cultural selection birdsong song learning urbanization vocal performance