Here comes a wonderful tidbit. Sparrows thriving in the towns change the pitch and dialect of their songs as they are fed up with irritating noises around them. Yes, this fact has come up as part of a study conducted by David Luther, term assistant professor of biology at Mason.
The study included a comparison on bird songs recorded from 1969 till date. San Francisco city, which was selected for the timeline study, has got noisier over the years. This was inferred from comparing studies conducted in 1974 and 2008 in the city.
There is a direct influence of the elevated loudness of the city in the song selection and noise of the birds. The study also has tried to record the responses of the sparrows of this generation to the past and present songs.
Birds who have settled down in the cities find it difficult to communicate when each and every time a car vrooms past them or when a factory blurts out a siren. They are forced to tweet louder, as per the Darwinian theory of survival of the fittest.
Luther observed that they opt for more than just increasing their volume. They have changed the tune and get rid of some old ones as well.
Those old songs couldn’t probably survive against the sounds of city commotion.