Variation in bird-window collision mortality and scavenging rates within an urban landscape

ABSTRACT Avian mortality from collisions with windows and buildings is one of the top sources of anthropogenic mortality of birds. Each year in the United States, an estimated 100 million to one billion birds die from window collisions. Many studies of bird-window collision mortality have aimed to identify architectural, landscape, and species-specific factors that may influence collision rates, but little research has assessed the potential for spatiotemporal variation in collision mortality. We studied window collision mortality at 42 residential houses located within an urban landscape, along the shores of Lake Superior in Duluth MN, USA from 2006–2009 to quantify window-related fatalities during migration. The rate of window collision mortality was modeled as a function of house location and season using Poisson regression. We also conducted carcass distribution trials to estimate scavenging and detection rates, and analyzed the resulting data using a multistate Markov model. We used hierarchical mode...