Effects of Urban Noise on Bird Diversity

Many studies have shown that products of urban development, such as anthropogenic noise, have an impact on the behavior of animals, especially birds. In the Central Valley of California, white-crowned sparrows and house finches have been shown to change their song in noisy areas. Urbanization and associated vehicular traffic present the biggest modern source of noise, and thus a novel context in which to study the effects of noise on bird diversity. This study examines how urban noise affects bird diversity in the Fresno-Clovis Metropolitan Area (FCMA). Using a point counts across the FCMA to census bird diversity, we concurrently measured average noise, percent ground cover (building, impervious surfaces, grass, dirt), and number of trees within a twenty meter radius of each point. Using these variables, we constructed a GIS model to better understand species presence and the acoustic soundscapes faced by urban birds. Further, we tested which factors best predict trill bandwidth in the white-crowned sparrow. The insights gained into how the urban environment affects biodiversity and animal behavior can help us better manage cities in ways that promotes biodiversity.