Degradation of male and female rufous-and-white wren songs in a tropical forest: Effects of sex, perch height, and habitat
We performed a song transmission experiment to investigate the effects of distance, song post height, receiver perch height, signaller sex, and microhabitat on song degradation in rufous-and-white wrens (Thryothorus rufalbus), a neotropical duetting songbird. We quantified the effects of these factors on excess attenuation, signal-to-noise ratio, tail-to-signal ratio, and blur ratio of male and female songs. As expected, song degradation increased with distance between signaller and receiver. Songs transmitted best when emitted from moderate heights (5-7 m), although this pattern varied with receiver distance, receiver height and microhabitat. The patterns regarding receiver height were subtle and inconsistent, but receivers may maximise their ability to hear male and female songs when perched at a height of 7 m and 5 m, respectively. Female songs were generally more degraded than male songs. Rufous-and-white wren songs appeared more attenuated in open field than forest habitats, but microhabitat conditions within the forests exerted a strong influence on song degradation. These findings match previous studies showing an effect of distance, song post height, and habitat, but contrast with other research by showing a minimal effect of receiver perch height. This study represents the first detailed investigation of differences in song transmission between males and females. © 2009 BRILL.
Barker, Nicole K.S.; Dabelsteen, Torben; and Mennill, Daniel J., "Degradation of male and female rufous-and-white wren songs in a tropical forest: Effects of sex, perch height, and habitat" (2009). Behaviour, 146, 8, 1093-1122.