Habitat

Nests in wide range of habitats, including salt marshes in northeast and mid-Atlantic region, rock and vegetated islands in Maine and Massachusetts, sandy beaches and islands in Florida and along Gulf Coast, and rocky and vegetated islands in Caribbean (Bent 1921, Bongiorno 1970, Nisbet 1971, Buckley et al. 1978, Schreiber et al. 1979, White et al. 1983a, Burger and Gochfeld 1985). In N. Carolina, uses dredge spoil and unmodified estuarine islands in proportion to their availability, with turnover rate (index of movement among colonies) of 10% (McCrimmon and Parnell 1983). In Florida Keys, nests on natural islands at base of mangroves (Rhizophora mangle) and other low herbaceous vegetation and tall grasses, with turnover rates of 29% (Frohring and Kushlan 1986). Optimal habitat is often in sparse or dense vegetation that provides some protection from inclement weather and predators. In 1940s, nested on sand at Muskeget I., MA (Noble and Wurm 1943).

Primarily along coasts, in estuaries, and along continental shelf. Roosts on inland lakes, bays, estuaries, and impoundments, as well as on open ocean (Stone 1937).

Primarily along coasts in littoral zone and in bays and estuaries. In Texas and Mexico, feeds in a variety of habitats including ocean, bays, river mouths, rivers, streams, and landfills (Burger and Gochfeld 1983a).