Laura Erickson's For the Birds

In breeding season, Seaside Sparrows are restricted to saltwater marshes from southern Maine to Florida along the Atlantic coast and from Texas to Florida along the Gulf coast, except for one Florida subspecies which is found in freshwater. The northeastern subspecies is migratory, and some individuals spend winter away from what we think of as appropriate habitat. They feed on seeds, insects, spiders, and other invertebrates.

The Seaside Sparrow may be considered a species of “least concern” by the International Union for Conservation of Nature, but one non-migratory subspecies, the Dusky Seaside Sparrow, found in Florida in the natural salt marshes of Merritt Island and along the St. Johns River., is extinct, and another, the Cape Sable Seaside Sparrow, restricted to South Florida, is endangered. The Cape Sable subspecies has very specific water level requirements—too high and nests become submerged, too low and the vegetation becomes inappropriate—so some people call it the Goldilocks bird because things must be “just right.”