Hayward, James*,1, Henson, Shandelle1, 1 Andrews University, Berrien Springs, MI
ABSTRACT- Loafing in birds is defined as a general state of immobility that involves a heterogeneous set of behaviors such as sleeping, sitting, standing, resting, preening, and defecating that occur outside the breeding territory. Loafing thus serves a variety of functions and cannot be considered a single behavior. Nevertheless, loafing is a useful term for a class of behaviors that often conflict with human interests. Among other concerns, loafing birds spread disease, transport contaminants, foul boats with feces, displace members of other species, and collide with aircraft. The ability to predict the incidence of loafing would provide a first step toward the amelioration of resultant bird/human conflicts. Here we discuss differential equation models that forecast the dynamics of numbers of loafing gulls. For the protected inland waters of Washington, models predicted numbers of loafing Glaucous-winged Gulls on a pier with an R2 of 0.63 and on a rock jetty with an R2 of 0.79. For a windy island off the coast of Maine, models predicted numbers of loafing Herring Gulls on rooftops with an R2 of 0.41 and combined numbers of loafing Herring/Great Black-backed Gulls on rooftops and a rock outcrop with an R2 of 0.47. Mathematical models that predict the dynamics of organism numbers in nature provide important tools for behavioral ecologists, epidemiologists, conservationists, and resource managers; they also suggest that deterministic factors, more than stochastic factors, control the behavioral dynamics of some complex animals.