Birds change song to be heard above traffic noise

[Cara J]

Vehicles are a major source of noise pollution for urban wildlife. That’s particularly a problem for birds that have to compete with the roar of engines to communicate. Recent research from Washington, D.C., suggests that some birds —those with innate rather than learned songs —modify their song structure to be heard over the din of traffic. In noisier conditions, these birdsongs are shorter and have a smaller range of frequency, said Katherine Gentry, lead author on the paper published in Bioacoustics. The birds raise their minimum frequencies, reducing their song’s overlaps with low frequency traffic noise. “That makes it easier for the receiver to detect the signal against the background noise,” said Gentry, a research assistant at George Mason University. Gentry wanted to see if suboscines, a family of birds whose song is innate rather than learned, could adjust their signal to communicate over traffic noise. Suboscine species include the vermilion flycatcher (Pyrocephalus rubinus), chocolate-vented tyrant (Neoxolmis rufiventris), white monjita (Xolmis irupero) and eastern wood pewee (Contopus virens). Although many studies have examined birds’ response to noise pollution from vehicles, this was the first to look at how suboscines in particular change their song in the absence of traffic during [...]

 

Read more: http://wildlife.org/birds-change-song-to-be-heard-above-traffic-noise/