A female perspective: testing the effects of noise masking on signal transmission patterns inside the nest box

Abstract

Abstract During the breeding season, avian pairs coordinate interactions with songs and calls. For cavity nesting birds, females inside nest boxes may rely on male vocalizations for information. Anthropogenic noise masks male songs, which could affect information gained by females. We explored song transmission from a female house wren (Troglodytes aedon) perspective, testing the hypothesis that noise masking alters songs that reach females inside nest boxes. We broadcast songs at three distances up to 25 m from nest boxes and re-recorded songs using two microphones, positioned inside and outside nest boxes. We measured signal-to-noise ratios and cross-correlation factors to estimate the effects of masking on transmission. In noise, songs received inside nest boxes had lower signal-to-noise ratios and cross-correlation factors than songs recorded outside of boxes, and these effects decreased with distance. For females, noise may reduce information conveyed through male songs and in response pairs may need to adjust their interactions.