Anthropogenic Effects on European Starling Nestlings Growth and Cholesterol

Urbanization is a leading threat to wildlife, and anthropogenic habitat modifications may alter the resources that wildlife have access to. For example, urban centers may provide animals with abundant anthropogenic food sources, though these foods may be lower in quality than natural food sources. The impact of living in urban centers on the growth, physiology and behavior of birds remains equivocal and can vary across species. We studied two free-living populations of European Starlings (Sturnus vulgaris); one at an urban farm (high human density) and one at a rural farm (low human density) in Kennesaw, GA. We monitored 100 nestlings across both sites and collected weight measurements to generate growth curves and collected blood samples to measure nestling cholesterol (index of dietary fats) and triglycerides (index of fattening rate). We hypothesized that urban nestlings will have slower growth rates, lower triglycerides, and higher cholesterol than rural nestlings. We also hypothesized that chick growth rates will be correlated to their behavioral coping style, where slower growing nestlings will have slower breathing rates and reduced struggling rates when handled. Future research will increase sampling at additional sites along an urban to rural gradient, examine parental behavior in selecting food sources for their nestlings, and assess additional indices of health and fitness