Humans add a lot of sound to their environments, particularly through motorized vehicles. During the 2020 pandemic shutdowns when people stayed home, the natural world suddenly became a much quieter place.
Scientists jumped on the opportunity to study how birds reacted to these newly changed soundscapes. While findings continue to be published, an early picture has emerged: the birds altered some of their behaviors, too.
Continuous vehicle noise found in urban areas creates a low-frequency (low pitch) hum, and birds living in these areas are known to sing louder and at higher frequencies in order to make themselves heard. One study found that without the masking traffic noise, White-crowned Sparrows sang more quietly and produced lower-frequency and higher performing songs. Other studies found that birds altered their daily routines and may have used a wider range of habitats during lockdowns.