Meeting Abstract

S2.3-1  Saturday, Jan. 4 13:30  Sex and disease in the city: links between coloration, parasites, and urbanization MCGRAW, KJ*; GIRAUDEAU, M; Arizona State University kevin.mcgraw@asu.edu

Expanding urban conditions across the globe continue to impose unique environmental constraints on organisms. Condition-dependent sexually selected traits are useful for revealing how animals cope with stress, including anthropogenic disturbances. Ornamental coloration of some bird species has been shown to be depressed in cities compared to rural/natural areas, but there are many plausible mechanisms that could underlie this pattern (e.g. pollution, diet, CORT stress). Since 2008, we have been studying factors related to the expression of carotenoid-based sexual coloration in house finches (Haemorhous mexicanus) along an urban gradient in Phoenix, AZ, USA. Among free-ranging birds, we have found close associations between plumage color intensity, degree of infection with two parasites (avian pox and intestinal coccidians), and degree of urbanization (i.e. human population, % disturbed land); male finches are less colorful and infected with more parasites in urban areas. We have also conducted common-garden experiments to test for latent (i.e. phenotypic plasticity) v. lasting (i.e. developmental/genetic) mechanisms underlying the links between color, parasites, and urbanization. Rural finches show superior ability to endure infection with some parasites, but we have not uncovered sustained urban/rural differences of color expression. These findings highlight the subtleties of assessing wildlife health along different axes of ‘condition’ and in urban environments.