Meeting Abstract
Disease dynamics in wild organisms depend upon a suite of intrinsic and extrinsic factors including host competence and immunocompetence, host community dynamics, and environmental composition. There is good data on disease risk varying across the landscape, but generally less information on whether and how host immune defenses vary across the landscape. Furthermore, there is strong empirical evidence that developing individuals of most species have reduced immune function compared to adults, but other than a broad trend for individuals raised in more resource-rich environments having stronger parasite defenses, we have little data on how immune function varies across the landscape in immature organisms. In this study we examined aspects of immune function in adults and nestlings of five bird species that co-occur in shrublands in the Midwest US with relatively similar life-histories. In addition to assessing interspecific variation and the relative values of nestlings compared to the adults, we examined whether immune function covaried with proportion of four different land-cover types at different spatial scales around the nest. We found interspecific variation in immune function as well as substantial differences in nestling immunological investment relative to adults. Furthermore, we documented covariance between some immune components and proportion of land-cover types, although this varied by species and age class. Our results highlight the importance of examining variation in immune function across the landscape, and in considering variation between nestlings and adults when assessing competence levels for a given species.
