FLYCATCHERS SING LONGER SONGS IN NOISIER SURROUNDS
Many species of birds are famous for their repertoire of songs, which primarily helps them find mates and guard territories. Some of them unfortunately live in urban areas, where there is simply too much noise. Scientists have studied the effects of varying noise levels on one group of songbirds, including nightingales, and found that birds sang higher pitched songs in noisier areas. There is another group of songbirds whose singing skills are not as well developed and therefore have been largely neglected. Some preliminary studies have shown that they might be singing a different tune, quite literally.
The song of the vermilion flycatcher is sung mostly before sunrise and is composed of certain elements in a particular order. Expecting higher pitched and longer songs, Alejandro and his colleagues recorded the songs of male flycatchers in parks and urban areas in Mexico City. They also recorded noise levels at different times of the day. But what they found was quite different from earlier studies. The birds did not increase the pitch of their songs to match the noise level. Instead, they sang longer songs with more elements. The authors do not generalize that all flycatchers will respond this way, and a study on the ash-throated flycatchers has found confounding patterns contrary to both this study and previous ones. One thing is for sure: birds can adapt and adjust their songs to be heard over and above the loud racket we create. Whether they all successfully reproduce and survive remains to be seen.
Ríos-Chelén AA, Quirós-Guerrero E, Gil D, & Macías Garcia C. 2012. Dealing with urban noise: vermilion flycatchers sing longer songs in noisier territories. Behavioral Ecology and Sociobiology, DOI 10.1007/s00265- 012-1434-0