Estimation of Distance of Singing Conspecifics by the Carolina Wren

Abstract

Abstract Measurements of the propagation of sound in a forest have shown that signal degradation is unavoidable but to some degree predictable. Carolina Wrens (Thryothorus ludovicianus) have a song structure suited for the estimation of distance by a comparison of the relative degradation of the components of the signal. Playback experiments using song recorded at two distances from a singing wren demonstrated that wrens can use cues other than the absolute attentuation of the sound for the estimation of the distance of the singer. The wrens responded to the near-sounding song by attack and to the far-sounding song by countersinging. The ability of the wrens to use the distance information in the song serves the same purpose as the recognition of familiar neighbors: conservation of time and energy used in territorial defense.