BONIER, Frances*; MARTIN, Paul R. ; JENSEN, Jay P. ; FOLTZ, Sarah; WINGFIELD, John C.; University of Washington: Stress in urban songbirds: adaptation to life in the city?

The vast majority of species are excluded from human-dominated landscapes, but some species persist and appear to thrive. By studying species that are established in urban habitat, we may gain insight into the traits that have allowed them to coexist with us. Here we present data on variation in basal and stress-induced corticosteroid levels within six populations of a Passerine bird breeding in both urban and rural habitats. Male Zonotrichia leucophrys had significantly higher basal and stress-induced corticosterone levels in urban habitat than birds in rural sites, but female birds did not differ. We discuss potential causes of this pattern, and present preliminary estimates of the associated fitness costs and benefits.