Common locally with plentiful food supply. Often near fast-moving water on rivers, ocean, and lakes but can be found anywhere. Birds follow circuits in flock while feeding before sitting down in groups. Picks food off surface. Has favored sites, e.g. Niagara River, where may gather in thousands when river not frozen over. Breeds in boreal marshes, usually nests in conifer trees. Tends not to mix with other species. Tight flocks often fly in unison. Prefers sitting on water to standing. ID: 2-yr gull. Small and dainty, almost tern-like, with light, buoyant flight and very clean appearance. Pointed wings. Striking wing pattern with translucent outer primaries and neat black trailing edge obvious even at long distances. Pale pink legs. Thin, pointed black bill. Gray extends from hind neck to breast sides. Ad br: slaty blackish hood. Legs bright pink to red. Ad nonbr: dark spot behind ear and pale pink legs. Juv: often orange base to bill; soon darkens. Mantle and head warm brown tones. 1st-w: mantle becomes pale gray and head whiter. Blackish carpal bar, tail band, trailing edge to wing and primary coverts distinguish from adult. Some birds in 2nd-w show signs of immaturity and thus can be aged.