Evaluating Relationships between Road Noise and Breeding Birds in the Conterminous United States

Abstract

Human activities have increased the amount of anthropogenic noise and altered the distribution of birds across the landscape, raising concerns about the possible effects of noise pollution on birds. Anthropogenic noise reduces the ability of birds to detect bird song, which is fundamental to their survival and reproduction. Although the worldwide anthropogenic noise exposure is substantial, little is known about how novel acoustical condition affects birds. The main objective of this thesis is to understand relationship between road noise pollution and breeding bird richness and abundance across different land cover classes in the continental United States. I hypothesized that human habitat and open habitat that support high bird abundance co-occur with areas of anthropogenic noise; and that bird richness decreases monotonically with increasing anthropogenic noise and urban areas. To test these hypotheses, I modeled bird richness and abundance in relation to road noise, land cover, and habitat types. I found a positive relationship between bird abundance and road noise and the closed-human habitat areas, but no relationship between bird richness and road noise. These results suggest that anthropogenic road noise and land cover play an important role influencing bird abundance in the conterminous US. This study provides an important step in advancing our understanding of anthropogenic noise on breeding bird populations and possibly other wildlife.