Birds are known to carry pathogens affecting human and agricultural health. Conversely, agricultural operations can serve as sources of pathogens that affect wild bird populations. This chapter provides guidelines to identify focal avian species that frequently use agricultural operations. These guidelines are coupled with identifying host types, such as maintenance and bridge hosts, and potential direct and indirect pathways for pathogen contamination from wild birds to agricultural operations, including patterns of spillover and spillback. The chapter also identifies major bacterial and viral pathogens of concern that are prevalent in birds and that affect human and agricultural health. These pathogens are then used to illustrate disease ecology concepts important at the wildlife–agriculture interface. These microorganisms include food-borne bacteria, influenza A viruses, and Newcastle disease virus. The chapter introduces the concept of contamination potential for categorizing avian species in terms of the risk they pose to contamination of agricultural operations with pathogens of concern. Finally, the chapter examines long-distance movements of wild birds in relation to pathogen introduction and illustrates this with global movement of influenza A viruses by wild birds.