Christian will be assessing several physiological conditions of barn owl nestlings from nest boxes to investigate the effects of nearby land cover on their health. These physiological conditions include feather growth bars, fault bars, heterophil-lymphocyte ratios, and corticosterone levels in feathers. Previous studies conducted in Napa Valley have demonstrated barn owl preference for uncultivated land cover in terms of hunting activity, prey availability, and nest box location. This study may further clarify how land composition in an agricultural setting can affect a species that provides an ecosystem service through the outcomes of habitat selection.