City Birds Are Changing Their Songs Because Of Urban Noise
San Francisco sparrows sound very different than sparrows a few miles away in the country. Could we be witnessing evolution in action?
Goldfinches living by the Madrid airport no longer sing at dawn. Instead, they start chirping before the first flights of the morning start to drown them out. It's an extreme example of something that's happening in every city: As cities get louder, wildlife are changing to adapt to the noise.