Roosting, Site Fidelity, and Food Sources of Urban Gulls In Massachusetts: Implications For Protecting Public Water Supplies [thesis]

Daniel E. Clark
Anyone who has spent time in coastal New England has seen gulls flying overhead and heard their familiar sound; gulls may be one of the most recognizable birds in the world. There are over 50 species of gulls worldwide, and many of them are closely associated with human development or activities. In Massachusetts, there are several common gull species including herring (Larus argentatus), great black-back (Larus marinus), laughing (Leucophaeus atricilla), and ring-billed (Larus delawarensis).
more » ... us delawarensis). While coastal encounters with gulls are ubiquitous, gulls can also be found inland, and ring-billed and herring gulls are now a common sight at lakes, parks, and commercial parking lots dozens or hundreds of kilometers from the ocean. This inland population of gulls presents unique challenges and exciting research opportunities. Because they are often closely associated with human activity, concentrations of inland gulls can lead to potential water quality concerns (when large roosts form on public water supply reservoirs), airplane hazards (when groups of gulls concentrate near airports or flight paths), or disease transmission (when gulls forage at landfills or waste water treatment plants then visit areas with people). In the following chapters I explore various aspects of inland gull ecology during the non-breeding season. In chapter 1, I review the concept of philopatry in birds and discuss ways to assess site faithful behavior. In Chapters 2 and 3, I explore some of the ecological aspects of inland gulls. Chapter 2 examines the site fidelity of gulls to their wintering areas and my results suggest that gulls exhibit high winter-site fidelity but variable site persistence during the winter season. Chapter 3 explores roost site selection throughout the year and models roost selection in Massachusetts. My results indicate that ring-billed gulls prefer freshwater roosts, while herring gulls use saltwater roosts more often. In Massachusetts, both herring and ring-billed gulls select inland freshwater roosts based on the si [...]
doi:10.7275/5428291 fatcat:mutbinf4jve6lhb6e2oxshzlim