Towards a Holistic Assessment of the Food-Safety Risks Imposed by Wild Birds

Birds introduce complex food-safety risks, as they carry multiple pathogens, are difficult to exclude from farms, and regularly defecate on crops. Yet very few wild bird species have been studied, and those that have form a minority of farm bird communities. Moreover, existing studies stop at examining pathogen prevalence in birds and do not holistically assess food-safety risk. For a species to pose a significant risk, it must carry pathogens, visit fields, defecate on crops, and produce feces that support pathogen survival. Here, we propose to first identify species that carry pathogenic E. coli, Salmonella, and Campylobacter by coupling existing studies with assays of field-collected feces. Second, we will survey birds and collect feces on 15-20 farms near rangeland, natural habitats, or other farms to determine which species enter farms and defecate on crops and in which contexts. Third, we will compare E. coli survival between feces placed on different substrates (crops, organic/conventional soils, plastic mulch) and between feces from different species. Finally, we will compile holistic risk assessments for >50 species into a photographic guide to help growers identify and manage birds. Ultimately, we hope to help growers implement practices that bolster beneficial species without compromising food safety.