Traffic hum leaves birds in less than chirpy state
Traffic noise may endanger wild birds by making it harder for them to hear alarm calls, a study suggests.
Scientists in the US tested how the sound of a busy road affected the way black-capped chickadees and tufted titmice reacted to titmouse calls warning of predators nearby.
While traffic noise from speakers set up near feeding platforms did not stop the birds looking for food, it appeared to mask the alarm calls. Five times as many birds approached the speakers when they broadcast alarm calls on their own than when alarm calls were competing with the sound of cars and lorries.
Professor Megan Gall said: "Additionally, a lot of this work focuses on song, but we were interested in how noise might affect responses to an anti-predator vocalisation." The findings were published in The Condor: Ornithological Applications.