Site Fidelity is Associated with Food Provisioning and Salmonella in an Urban Wading Bird

AbstractFood provisioning can change wildlife pathogen dynamics by altering host susceptibility via nutrition and/or through shifts in foraging behavior and space use. We used the American white ibis (Eudocimus albus), a wading bird increasingly observed in urban parks, as a model to study synergistic relationships between food provisioning and infection risk across an urban gradient in South Florida. We tested whetherSalmonella prevalence was associated with changes in ibis diet (stable isotope analysis), space use (site fidelity via GPS tracking), and local density (flock size). We compared the relative importance of these mechanisms by ranking candidate models using logistic regression. We detectedSalmonella in 27% of white ibises (n = 233) sampled at 15 sites. Ibises with diets higher in anthropogenic food exhibited higher site fidelity.Salmonella prevalence was higher at sites where ibises exhibited greater site fidelity andSalmonella was more prevalent in soil and water. Overlap inSalmonella serotypes between ibises and soil or water also was more likely at sites where ibises exhibited higher site fidelity. Our results suggest that repeated use of foraging areas may increaseSalmonella exposure for birds if foraging areas are contaminated from animal feces, human waste, or other bacterial sources. Limiting wildlife feeding in parks —perhaps best achieved through understanding the motivations for feeding, education, and enforcement—may reduce health risks for wild...
Source: EcoHealth - Category: Environmental Health Source Type: research