Use of Great Lakes Recreational Beaches and Human-Waste Sites by Ring-Billed Gulls

Larus delawarensis (Ring-billed Gull) populations have increased >4% annually in the Great Lakes region since 2003. Gull–human interactions and conflicts have similarly increased, particularly concerning human health and safety issues related to gull feces deposited at recreational beaches. During June–August 2013, we conducted a radiotelemetry study of Ring-billed Gulls in a Lake Michigan coastal region to determine patterns of habitat use and movement between recreational beaches and human infrastructure by gulls. Of 14 individuals relocated, we found Ring-billed Gulls selected recreational beaches and landfill sites and avoided agricultural fields. We found 5 of 14 gulls made a minimum of 2 roundtrips between beaches and landfills over the study period. Gulls may serve as transport vectors for bacteria and other pathogens from human-waste sites to areas of probable human contact and concentration, such as public recreational beaches. As such, pathogen distribution and connectivity within a landscape could be established, maintained, and enhanced by gull movements. Managers may need to implement exclusion tools for gulls at both of these sites to maintain human-health standards.