Northern Prairie Wildlife Research Center
STATUS: Common; of special concern on the blue list; declining on East Coast.
HABITAT: Uses a variety of habitats, mainly near water, often on islets, and usually in areas with little or no vegetation. Inhabits sparsely vegetated sandy islands, barrier beaches, marshy islands, small islands in salt marshes, or low, small, rocky islands in lakes and rivers. After nesting, typically found along shorelines, on exposed rocks and old pilings, and inshore over shallow coastal waters.
SPECIAL HABITAT REQUIREMENTS: Nesting areas with scant vegetation, isolated from disturbance and predation, and in close proximity to a source of food.
NEST: Builds nests in colonies; nests may vary from a slight hollow in sand or among pebbles to a well-built hollowed mound of grasses and seaweeds, may be in the open or near weeds, grasses, or bushes. Generally prefers sparse cover around the nest.
FOOD: Forages in shallow waters, margins of lakes, or along the coast, but tends to avoid muddy waters. Consumes a diet that varies with locality, including fish less than 6 inches, shrimp and other crustaceans, aquatic worms, insects, and some waste material.
REFERENCES: Burger and Lesser 1978, Forbush and May 1955, Johnsgard 1979, Palmer 1941, Tate and Tate 1982.