Migratory bird stopover patterns linked to urbanization and social landscapes

Despite global urbanization, the role of cities in macroecological processes remains understudied. Using radar estimates of migratory bird stopover across the U.S., we assessed urban landscapes' contributions to stopover and links to social demographics for 2,130 parks across 88 cities. Stopover hotspots disproportionately occurred on urban landscapes relative to land area, with nearly 50% of spring migration hotspots falling within Metropolitan Statistical Areas. The relationship between urbanization and stopover varied regionally, correlating negatively in eastern flyways and positively in western flyways. Finally, stopover was positively correlated with household income but varied considerably, with many cities showing no effect or an effect in the opposite direction. We highlight the significance of cities in a hemispheric-scale ecological process and demonstrate radar as tool for studying urban social-ecological interactions.