When Noise Annoys: Testing the Effects of Chronic Noise Exposure on the Antipredator Behavior and Reproductive Success of Breeding House Sparrows, Passer domesticus

Since the industrial revolution, urbanization has significantly increased levels of background noise; sounds generated by machinery, transportation networks, and human traffic have altered the structure, frequency, and intensity of noise to which natural systems are typically exposed. Birds, as highly vocal species, are particularly susceptible to changes in the acoustic environment, with background noise potentially interfering with those cues essential for perception and communication. Although urban development has been associated with decreases in species abundance and diversity, less is known about how noise—in isolation of the physical roadway—has directly affected this decline. To date, the majority of research has focused on the effects of noise exposure on vocal behavior and the acoustic masking of survival-related vocalizations. However, the conclusions of such studies, i.e. birds show a remarkable ability to adapt to noise through spatial, temporal, and vocal adjustments, may underestimate the negative effect of noise pollution on wildlife. Here, I investigate whether prior exposure to noise has lasting effects on the behavior and, consequently, the reproductive success of breeding house sparrows, Passer domesticus. I exposed free-living house sparrows to chronic noise during late incubation and, upon noise cessation, assessed whether birds differed in their response to select cues of predation. Although I found no effect of noise treatment on reproductive success, female sparrows exhibited more intense responses to novel stimuli when subject to prior noise exposure