Saltmarsh Sparrow

The saltmarsh sparrow measures 11–14 cm (4.3–5.5 in) in length, has a wingspan of 17.8–21 cm (7.0–8.3 in), and weighs 14–23.1 g (0.49–0.81 oz). Adults have brownish upperparts with a gray nape, white throat and belly, and pale orange breast and sides with brown streaking. The face is orange with gray cheeks, a gray median crown stripe, brown lateral crown stripes, and a brown eyeline. The tail feathers are short and sharply pointed. The subspecies A. c. diversa has more contrasting striping on its back and a darker crown than the nominate A. c. caudacuta. Only males sing. The song is a complex series of raspy, barely audible buzzes, trills, and gurgles. It is distinguishable from that of the Nelson's sparrow, which is a louder, hissing buzz followed by a buzzy chip. The high-pitched contact calls of both species are indistinguishable. Distinguishing this species from closely related sparrows such as the Nelson's sparrow (Ammospiza nelsoni) can be difficult. The inland subspecies of the Nelson's sparrow can be differentiated by its fainter streaking and brighter orange breast and sides, while the coastal subspecies of the Nelson's sparrow can be differentiated by its paler, less-contrasting plumage. The saltmarsh sparrow also has a slightly longer beak than the Nelson's sparrow.

The saltmarsh sparrow is only found in tidal salt marshes along the Atlantic coast of the United States. It breeds along the northern coast, from Maine to the Chesapeake Bay, and winters along the southern coast, from North Carolina to Florida. The saltmarsh sparrow prefers high marsh habitat, dominated by saltmeadow cordgrass (Sporobolus pumilus) and saltmarsh rush (Juncus gerardii), which does not flood as frequently as low marsh.

The saltmarsh sparrow forages on the ground along tidal channels or in marsh vegetation, sometimes probing in the mud at low tide. Over 80% of the diet of nestlings consists of flies, amphipods, grasshoppers, and moths, especially larval, pupal, and adult soldier flies. During the winter, adults consume seeds. The saltmarsh sparrow is an opportunistic feeder and food is rarely limiting.