Gulls and Terns
NOTE: Initial Descriptions in this section were taken from [Merlin]. They will be modified to reflect and include local information.
Small, pale gull with white underparts and gray back. Thin, black bill. Often seen in flight. Note unique wing pattern: several outer primaries white with black tips. Red legs. Adults in breeding plumage show black head. Nonbreeding and immatures have white head with black spot behind eye. Immatures also show white primaries with blackish-brown markings on the upperwing. Often seen in large flocks in coastal areas, bays, coves, and lakes during migration and winter. Feeds on small fish, invertebrates, and insects, often picking them off the surface in flight. Breeds near water in the boreal forest; the only gull that makes a stick nest.
Widespread and common inland gull in the U.S. and Canada. Forages along lakes, rivers, and ponds, as well as, plowed fields, mall parking lots, and parks. Often in flocks sitting on ground or flying between roosting and foraging sites. Smaller and more slender than Herring Gull with thinner bill. Compared with California Gull, adults are lighter gray on back, thinner billed, and lack red spot on bill.
Widespread and often common inland and on the coast. Adults have gray back with black wingtips. Takes four years for immatures to progress from mostly brown to white and gray; intermediate plumages are often mottled and messy. Varies incrementally across a wide geographic range. Scavenges shorelines, mudflats, plowed fields, and open ocean, picking up scraps wherever it can. Often congregates in large groups with other gulls, especially around fishing boats, beaches, piers, and landfills. Far-carrying yelping screams are a common sound of waterside habitats around the world.
Great Black-Backed Gull
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.
Largest tern in the world. Thick, bright-red bill is distinctive. Note solid black cap in summer, which turns to black streaks in winter. Feeds by cruising over lakes, rivers, estuaries, and reservoirs looking for fish, then plunging to catch them. Smooth wingbeats, more gull-like than choppy flight of small-bodied terns. Very vocal, giving loud raucous screams.