Comments: BREEDING: Shallow freshwater and saline ponds, marshes and wet meadows (AOU 1998). Nests on the ground in wet meadows, grassy marshes, and along edges of shallow inland waters. The nest is a well-concealed scrape, lined with grass. Uses both fresh and alkali wetlands with three characteristics: open water, emergent vegetation, and open shoreline (Saunders 1914, Hohn 1967, Stewart 1975, Prescott et al. 1995, Naugle 1997). Nesting habitat varies widely, including wetlands, wet meadows, upland grasslands, and road rights-of -way (Bent 1927, Roberts 1932, Hohn 1967, Stewart 1975, Murray 1983, Bomberger 1984, Colwell 1987, Colwell and Oring 1990, Einemann 1991, Faanes and Lingle 1995, Dinsmore and Schuster 1997). Occasionally occur in Conservation Reserve Program (CRP) fields and dense nesting cover (Johnson and Schwartz 1993; Prescott et al. 1993; D.H. Johnson, unpubl. data).
In North Dakota, densities were highest in undifferentiated tillage wetlands (wetlands with frequently tilled soils), followed by temporary, seasonal, semipermanent, fen, alkali, and permanent wetlands (Kantrud and Stewart 1984). Often occupied the peripheral low prairie and wet-meadow areas of most classes of wetlands in North Dakota. In South Dakota, occurrence was associated positively with the presence of seasonal and semipermanent wetlands, stock ponds, and intermittent streams; area of alfalfa (MEDICAGO SATIVA) hayland; area of surface water; and the percentage of grazed shoreline (Weber 1978, Weber et al. 1982). In eastern South Dakota, the probability of occurrence in semipermanent wetlands was related positively to the proportion of untilled uplands and the number of emergent hydrophyte species (e.g., willow [SALIX spp.]) composing > 10% of the vegetated wetland area; were associated negatively with wetlands dominated by thick-stemmed plants (e.g., cattail [TYPHA spp.] and river bulrush [SCIRPUS FLUVIATILIS]) (Naugle 1997). Within seasonal wetlands, the probability of occurrence was related negatively to wetlands dominated by thick-stemmed plants (Naugle 1997).
Nest site selection varies seasonally. Nests in upland vegetation early in the breeding season and wet-meadow vegetation later in the season (Colwell and Oring 1990). Usually nests less than 100 meters from shoreline (Hohn 1967, Hatch 1971, Colwell and Oring 1990, Eldridge in prep.). Nest sites in Nebraska were in wet sedge (CAREX) meadows (Faanes and Lingle 1995). In North Dakota and Iowa, nested in wetlands associated with river floodplains (Murray 1983, Koenig 1984). In Alberta, Saskatchewan, and North Dakota nested in grasses of various heights on islands or in wet-meadow zones around lakes and wetlands; in Saskatchewan, brood rearing occurred in patches of foxtail barley (HORDEUM JUBATUM) (Bent 1927, Hohn 1967, Kagarise 1979, Colwell 1987). In Saskatchewan, Colwell and Oring (1990) found that nest sites had taller, denser, and more homogeneous vegetation and less bare ground than randomly selected sites. However, in the Nebraska sandhills, nest sites had shorter vegetation than random sites (Bomberger 1984).
NON-BREEDING: on lake shores, mudflats, salt marshes, freshwater marshes, alkaline ponds; rarely along seacoasts; stages on salt lakes (Colwell and Jehl 1994, AOU 1998). Also at sewage ponds; rarely reported at sea.