Seaside Sparrow

New York Status: Special Concern
Federal Status: NY Subspecies (A. m. maritima) - Not Listed, Cape Sable Seaside Sparrow (A. m. mirabilis) - Endangered

Description

Appropriately named, the seaside sparrow is a salt marsh specialist with 9 recognized subspecies throughout its range along the Eastern and Gulf coasts of North America. One subspecies, the dusky seaside sparrow (A. m. nigrescens), became extinct in 1987 when the last remaining individual in captivity died.

The seaside sparrow is distinguished from other sparrows by its overall gray coloring, large size, and long, conical bill. Sexes are alike with distinct yellow markings above the eye, on the supercilium (stripe running from beak to above eye), and on the edge of the wing at the wrist. Adult measures 5 to 6 inches with a short, spiky tail. This sparrow is similar to the sharp-tailed sparrow (Ammodramus caudacutus), but the seaside sparrow is larger and grayer. The juvenile is similar to adults but with less streaking and brown upper parts.

Life History

Males arrive on breeding marshes approximately one week before females beginning in late March. They form pair bonds immediately after the arrival of the females. Males actively defend their territories and engage in combat with other males who invade their territory. Birds may continue nesting until mid-July and renesting is common after failed nest attempts. The female alone builds the nest and incubates the clutch of 2 to 5 eggs. The nest is an open cup of grasses often constructed in tall vegetation in the wettest part of the marsh. Pairs are monogamous and territorial throughout the breeding season but will feed well outside of the defended territory. Young leave the nest after 9 to 11 days and usually form loose flocks with other fledglings and juveniles near feeding areas.

Distribution and Habitat

The seaside sparrow has a very limited breeding range that extends along the Atlantic Coast from New England to northern Florida. Breeding populations within this range are discontinuous and localized. In New York, the seaside sparrow is a rare and local breeder restricted mainly to the maritime area. The largest tract of suitable habitat is found on the barrier islands that line the south shore of Long Island. Year round populations are found along the Gulf Coast of Florida west to Texas, and along the Atlantic Coast from Florida north to the Carolinas. Populations in the northeast are migratory. Habitat requirements for the seaside sparrow include elevated vegetation for nesting and open areas for foraging of insects.

Status

Habitat alteration is the most likely reason for the decreased abundance of the seaside sparrow in Long Island over the last half century. Alterations and fragmentation of habitat is widespread throughout this species range. Changes in Breeding Bird Atlas data over 20 years illustrate that the breeding population is becoming less widespread. It is listed as a Watch List species by the National Audubon Society.

Management and Research Needs

Habitat loss resulting from coastal development and habitat degradation from pollution are the biggest threats to the seaside sparrow in New York and throughout its entire range. Wetland protection and management are necessary to maintain optimal nesting and foraging areas for this habitat specialist.