Tweets in burbs

Sparrows and blackbirds are known to sing at a higher pitch in urban environments to escape low-frequency city noise of traffic and human activities. A new research suggests that high-frequency chirping also helps the city birds penetrate the architectural design of cities, making communication easier. A group of researchers, who used sound recordings, claims high notes do not produce many echoes on their way through the various surfaces of the city landscape. That way, the sound is clearer when it reaches its destination, say the researchers.

Source

Down to Earth, March 2012