Meeting Abstract
Pathogens are known to have a strong influence on fitness of wild birds. A well-known dynamic of disease ecology is the link between increased population density and increased pathogen prevalence. While many songbirds gather at bird feeders in large densities, birds of prey tend to be more solitary, or at least far less gregarious. We used a population of free-living songbirds and raptors to assess pathogen prevalence among birds and to assess the physiological consequences of harboring the pathogens. We used both field identification of pathological symptoms and PCR techniques to test for the presence of two different pathogens that can have a serious impact on the overall health of birds: the pathogenic bacteria, Mycoplasma gallisepticum and Mycoplasma synoviae (causative agents of conjunctivitis) and Avipoxvirus (the causative agent of avian pox). To estimate the impact of these diseases on host health, we also examined immune and physiological profiles of each bird. Severe symptoms were seen far more commonly in feeder-using birds at study sites with bird feeders than in songbirds at sites without feeders and raptors. In addition, birds with any of these pathogens showed greater heterophil to lymphocyte ratios and lower total antioxidant capacity. Overall, this study reveals important disease dynamics and host responses in multiple avian species.
