Sterna forsteri

Freshwater and salt marshes, in migration and winter also seacoasts, bays, estuaries, rivers and lakes (AOU 1983). Nests on inland lakes and marshes, or on salt marshes (especially on wrack) along the coast. Along the Gulf Coast, commonly nests on dredged material as well as on wrack in salt marshes. At San Francisco Bay, California, commonly nests on old dikes or dredged-material islets in salt evaporation ponds. Nests on floating mass of marsh plants, on muskrat house, or old grebe's nest, or in a depression lined with grasses and pieces of shells. Human-made nesting platforms made of bundles of PHRAGMITES or TYPHA on floating base of styrofoam and wood or tires were readily used for nesting in Wisconsin (see Spendelow and Patton 1988). See Spendelow and Patton (1988) for further information on freshwater nesting habitats. See Cuthbert and Louis (1993) for information on nesting habitat in Minnesota.

Breeding: Forage up to 3.2 kilometers from nest (Van Rossem 1933). Nonbreeding: singly or in small loose groups.

Along the U.S. mid-Atlantic coast, lays eggs from late May to mid-June. Both sexes incubate usually 3-4 eggs for about 23-24 days. Semi-precocial young are tended by both adults until capable of flight, fledge at 3-4 weeks, remain with parents well into the fall (Byrd and Johnston 1991). Often renests if first nest is lost to tidal flooding. Nests in loose colonies or singly. Colony size along the Atlantic coast is less than 500, up to several thousand in Louisiana (Spendelow and Patton 1988).