Habitat

Coastal areas: sand or shell beaches, dunes, salt marsh, rarely rocky islands (West Indies). Nesting habitat includes: (1) marsh islands—low islands, surrounded by intertidal Spartina alterniflora marsh or mud flats, with a substrate of sand, tide wrack, and S. patens; (2) upland dune—higher sandy areas that are part of a primary or secondary dune system, dominated by Ammophila, Spartina, Solidago sempervirens, or Laythurus japponica, well above mean high water; (3) beach—includes both flat, nearly level open sand areas with little or no vegetation, and small residual dunes in periodically flooded areas; and (4) dredge spoil—usually flat and nearly level elevated areas of various substrates—sand or gravel, sparsely to densely vegetated with Ammophila, S. sempervirens, and dusty miller Artemesia stelleriana (Zaradusky 1985, Lauro and Burger 1989, Humphrey 1990). In se. U.S., typically nests on open sand or shell substrates (Bent 1929, Tomkins 1954, Rappole 1981, Shields and Parnell 1990). More commonly nests in salt marsh toward northern end of range, probably to escape human disturbance (Frohling 1965, Lauro and Burger 1989, Humphrey 1990, Shields and Parnell 1990; see also Breeding: nest site). On the West Coast, and in Argentina, this species nests on shell banks: flat, narrow projections, 1–2 m above high water and made up almost entirely of unbroken shells; or on cobble spits (Bancroft 1927, EN). In the West Indies and Bahamas, nests sometimes on small rocky keys (Edwards 1989, Raffaele 1989).

Typically feeds in intertidal mud or sand flats, or on shellfish beds; roosts on adjacent beaches, dunes, or marsh islands, rarely venturing inland (RCH).

Typically concentrates in areas of abundant food, oyster beds, or reefs; clam flats and suitable roosting places; open ground without vegetation near suitable feeding habitat (Tomkins 1954, Cadman 1980, Jehl 1985). In most of range, birds are resident (Fig. 1).