Habitat

Principal habitats are low portions of coastal wetlands dominated by cordgrass (Spartina sp.), pickleweed (Salicornia spp.), or mangroves. These are wetlands with salinity of >7,100 ppm at low tide, and >5,600 ppm at high tide (Meanley 1985). See Breeding: nest site, below. Major coastal habitat types include marshes dominated by Pacific cordgrass (Spartina foliosa; Foin and Benchley-Jackson 1991), Pacific cordgrass–pickleweed-mix (Harvey 1988), salt marsh cordgrass (Spartina alterniflora), needlerush (Juncus roemerianus), salt meadow cordgrass (Spartina patens), red mangrove (Rhizophora spp.), black mangrove (Avicennia spp.), and white mangrove (Laguncularia spp.; Hon et al. 1977, Owre 1978, Holliman 1981, Meanley 1985).

Habitat on East Coast of U.S. ideally has emergents and scattered shrubs bordering ditches or tidal creeks within 15 m of open water, and at least 25% of total wetland area within 15 m of a shoreline (Lewis and Garrison 1983). Preferred habitats in New Jersey are natural and ditched short-form salt marsh cordgrass (most preferred), tall-form salt marsh cordgrass, and salt meadow cordgrass (least preferred; Mangold 1974). Very few individuals recorded in salt meadow cordgrass.

Nesting habitat in San Francisco Bay, CA, characterized by presence of tidal sloughs; abundant invertebrate populations; pickleweed coverage with extensive cordgrass coverage in lower zone; and tall pickleweed, gum plant (Grindelia cuneifolia), and wrack in upper zone (Harvey 1988). Nesting habitat in s. California includes tall, dense Pacific cordgrass in the low littoral zone, wrack deposits in the low marsh zone, and hummocks of high marsh within the low marsh zone (Massey et al. 1984). Fringing areas of high marsh serve as refugia during high tides (Zembal et al. 1989, Shuford 1993). Although used infrequently, this habitat may be extremely important at reducing mortality during high tides.

In Arizona, found in variety of marsh types dominated by emergent plants, including southern cattail (Typha domingensis), bullwhip bulrush (Juncus californicus), three-square bulrush (Scirpus olneyi), and sedges (Cyperaceae; Todd 1986). Presence of emergent cover, not plant species or marsh area, is important trait of habitat in Arizona (Anderson and Ohmart 1985). Arizona habitat includes sites with high coverage by water, low stem density, and moderate water depth used for foraging during nesting season; sites with shallower water near shorelines are used for nesting (Conway et al. 1993). Ideal habitat has mosaic of emergent plant stands of different ages interspersed with shallow pools of open water.

Little information. Presumably uses salt and brackish marshes similar to breeding areas. Sometimes observed in freshwater marshes or unsuitable habitats such as rock jetties during daytime stopovers, but moves onward the next night (Glick 1963, Meanley 1985). May move overland, as indicated by the fact that birds collide with stationary objects.

Winter habitat similar to breeding habitat. Abundance of populations on East Coast of U.S. may vary greatly in winter, depending on tide, wind, amount of ice, and temperature (Meanley 1985). Wintering birds in N. Carolina move from low marsh to mixed salt marsh cordgrass, needle-rush, salt meadow cordgrass, and shrub-dominated habitats (Adams and Quay 1958). Often occurs near drifts of logs and wrack during windy weather (Simmons 1914). In winter, Clapper Rails in freshwater marshes in Arizona exhibit narrower habitat breadth (Anderson and Ohmart 1985, Conway et al. 1993). Habitat used in early winter (Nov–Dec) in Arizona has lower emergent stem density, basal coverage, and ground coverage; less distance to water; greater overhead coverage by vegetation, distance to adjacent uplands, distance to vegetative edges, water depth, and water coverage; and taller emergent plants than do randomly selected sites (Eddleman 1989, Conway et al. 1993).