Largest gull in the world. Adults have dark black backs that contrast with their white body feathers. Thick bill and large size help separate immatures from other gulls. Also, note whiter head and colder black-and-white tones than immature Herring Gull. Found primarily at coastal sites in the Northeast U.S., the Great Lakes, and Europe. Hardy and fierce, it patrols open water and beaches for prey and scavenging opportunities.