Coastal Rufous-collared Sparrows modify their song to reduce surf-noise masking

CANALE, ELISABET; LIJTMAER, DARÍO A.; TUBARO, PABLO L.

Congreso; 2020 Animal Behavior Society Virtual Conference; 2020

Animal Behavior Society

Acoustic signal transmission is deeply intertwined with the surrounding environment and is constrained by noise. Birds have been shown to use different strategies to avoid the masking effect of both natural and anthropogenic noise. However, the effect of surf-noise on the song structure of passerine birds has never been studied. Here, we present the first analysis of this kind using Rufous-collared Sparrows (Zonotrichia capensis) living along the coastal environment in central Argentina as our model. This species? song includes an introduction and a final trill. In January 2020 we recorded the songs of 30 individuals living close to the coast or far inland where the surf-noise is negligible. We also measured noise levels after recording each individual. The spectrographic analysis showed that the trills of coastal individuals have higher minimum frequencies and narrower bandwidths compared to those of the inland. We interpret these results as evidence that Rufous-collared Sparrows living near the surf zone modify their song to avoid the masking effect produced by the low frequency noise generated by the waves.