The Swamp Sparrow is a common, if elusive and local, resident of the eastern United States and boreal Canada. Described by John Latham in 1790, and named after the state (Georgia) where the species was first collected, this sparrow is more easily detected by its song or call than by sight. Its clear, slow, liquid trill or metallic chink are often the only indication of its presence in the inaccessible habitats it occupies.
Aptly named, the Swamp Sparrow is seldom found far from water during the breeding season. Its preferred breeding habitat includes freshwater cattail (Typha sp.) marshes, brushy meadows, bogs, sedge (Carex sp.) swamps, and brackish marshes. Optimal habitat is found in large marshes with open water, dense low vegetation, and available singing perches.
The Swamp Sparrow is primarily monogamous and territorial throughout its range and, under optimal conditions, may occur at high densities. Composed of three morphologically distinct subspecies, that breed from boreal forest wetlands of Canada to salt marshes of the mid-Atlantic. It nests just above the ground or the surface of water and thus is subject to nest mortality from flooding. It is well adapted to foraging in and at the edge of water.
Song development, structure, and ontogeny have been well studied in the Swamp Sparrow, and recent research has significantly increased our understanding of breeding ecology, wintering ecology, and habitat selection. This research identified wetland loss throughout the range as a primary threat to the species. A concerted conservation effort needs to be established to maintain genetic diversity among Swamp Sparrow subspecies and populations, and the wetland habitats that this species depends upon.