Sparrows who live in the big city have learned to speak up in order to be heard: Researchers examined the songs of those that live around the Golden Gate Bridge and found that the calls are in a higher pitch now than they were in 1965, according to an Animal...
Birds can sing louder at higher frequencies and thereby make themselves heard over traffic noise. Read Post
White-crowned sparrows in San Francisco are singing louder in 2011 than they did in 1969 and reachers say its because they need to compete with more traffic congestion which has caused loud driving conditions to drown out their orig... Read Post
Sparrows, blackbirds and the great tit are all birds known to sing at a higher pitch (frequency) in urban environments. It was previously believed that these birds sang at higher frequencies in order to escape the lower frequencies ... Read Post