Seaside Sparrow, Ammospiza maritima

Original descriptionFringilla maritima Wilson 1811

eBird range map

Taxonomic history at Avibase

Taxonomic history in AOU/AOS Check-list 

AOU 1 (1886): Seaside Sparrow, Ammodramus maritimus; Dusky Seaside Sparrow, Ammodramus nigrescens

AOU 2 (1895): Seaside Sparrow, Ammodramus maritimus; Scott’s Seaside Sparrow, Ammodramus maritimus peninsulae; Texas Seaside Sparrow, Ammodramus maritimus sennetti; Dusky Seaside Sparrow, Ammodramus nigrescens

AOU 3 (1910): Seaside Sparrow, Passerherbulus maritimus maritimus; Scott’s Seaside Sparrow, Passerherbulus maritimus peninsulae; TexasSeaside Sparrow, Passerherbulus maritimus sennetti;LouisianaSeaside Sparrow, Passerherbulus maritimus fisheri;Macgillivray’sSeaside Sparrow, Passerherbulus maritimus macgillivraii;Dusky Seaside Sparrow, Passerherbulus nigrescens

AOU 4 (1931): Northern Seaside Sparrow, Ammospiza maritima maritima; Macgillivray’s Seaside Sparrow, Ammospiza maritima macgillivraii; Scott’s Seaside Sparrow, Ammospiza maritima peninsulae; Wakulla Seaside Sparrow, Ammospiza maritima juncicola; Howell’s Seaside Sparrow, Ammospiza maritima howelli; Louisiana Seaside Sparrow, Ammospiza maritima fisheri; Texas Seaside Sparrow, Ammospiza maritima sennetti; Dusky Seaside Sparrow, Ammospiza nigrescens; Cape Sable Seaside Sparrow, Ammospiza mirabilis

AOU 5 (1957): Seaside Sparrow, Ammospiza maritima maritima, Ammospiza maritima macgillivraii, Ammospiza maritima pelonota, Ammospiza maritima peninsulae, Ammospiza maritima juncicola, Ammospiza maritima fisheri, Ammospiza maritima sennetti; Dusky Seaside Sparrow, Ammospiza nigrescens; Cape Sable Seaside Sparrow, Ammospiza mirabilis

AOU 6 (1983): Seaside Sparrow, Ammodramus maritimus [maritimus group, nigrescens group, mirabilis group]

AOU 7 (1998): Seaside Sparrow, Ammodramus maritimus [maritimus group, nigrescens group, mirabilis group]

IUCN Conservation StatusOf least concern

The last Dusky Seaside Sparrow, a male, died in captivity in Florida in June 1987. Destruction of marsh habitat by drainage, impoundment, and uncontrolled fire had significantly reduced the population when in 1973 the AOU determined that the birds should no longer be recognized as a distinct species, a status they had enjoyed for 100 years. In one of the clearest demonstrations ever recorded of the connection between taxonomy and the politics of conservation, the public interest and governmental effort devoted to the Dusky Seaside Sparrow were greatly reduced by the “lump.” By the time a captive breeding program was initiated in 1979, the entire population, probably approaching 2,000 individuals ten years earlier, comprised six males—and no females. Five of those surviving birds were captured, and in the spring of 1980, one of the males was bred to a female Scott Seaside Sparrow; three fledged young were the result. It was planned that the two intergrade females produced in that brood would be backcrossed with Dusky males, and so on through the generations until the young were as like pure Dusky Seaside Sparrows as possible. In 1981, however, the Florida Game Commission ceded custody of the Dusky males to the US Fish and Wildlife Service, which declined to make them available for further breeding. 

The Cape Sable Seaside Sparrow has been federally listed as endangered since 1967; over the seventeen years beginning in 1992, its total population decreased by more than half, to only 3,120 surviving individuals. Existing as scattered subpopulations in the Everglades, the sparrow is imperiled by erratic water levels on the freshwater prairies where it breeds. Both flooding and parching prevent successful nesting, and abnormally low levels can lead to excessively frequent wildfires in open grassy habitats—though fire at appropriate intervals is a vital management tool in preventing the encroachment of woody vegetation. Inappropriate water management and manipulation continue to pose a significant threat to the survival of this bird even today, as a suit filed in 2015 against the Army Corps of Engineers, the US Fish and Wildlife Service, and the Department of the Interior asserts.  

Occupying habitats that are by definition downstream from human settlement, all Seaside Sparrow populations throughout the species’ range are susceptible to contamination by runoff containing herbicides and other chemicals. Rising sea levels caused by global warming can be expected to result in an acceleration of the loss of the salt marsh habitats required by all coastal populations of this species. The Seaside Sparrow is listed as a threatened species in Connecticut; a species of special concern in Rhode Island, New York, and Florida (Scott Seaside Sparrow); and as imperiled in Alabama (Scott Seaside Sparrow).

Behavior: Most Seaside Sparrows are not especially shy of humans, but their soggy habitat preferences can make a close approach uncomfortable for the observer. The birds are usually most easily watched when a rising tide pushes them onto the mud of tidal creeks and mosquito ditches or onto the edges of causeways and roads. Feeding birds stride across the ground on large, sturdy feet, wading confidently into the water; they may run or, less frequently, hop when startled back into cover. The long bill is used to seize prey from the base of vegetation or from beneath the surface of the water and mud.

This species is a notably skilled climber, often seen scaling, toe by toe, cordgrass stalks or the small twigs of bay and other high-marsh shrubs, where the sparrows take insects or seeds. 

The bulky body, wide tail, and short, rounded wings make Seaside Sparrows erratic flyers, though they are known to hover briefly to take insects from the air. Obviously, birds from the migrant populations of the nominate race are able to fly strongly over long distances, but on the breeding and wintering grounds, flight is usually low and poorly directed, the tail loosely flopping and short wings whirring. Seaside Sparrows often give the impression of deciding only abruptly and at the last possible moment to land, dropping unceremoniously into the cover of dense vegetation and often re-emerging after a few seconds by climbing a grass stem to sing or to examine their surroundings.      

“Play” behavior is well documented in this species. Unfortunately, the lively curiosity shown by Seaside Sparrows can also lead them into dangerous situations; “a penchant for working their way into narrow crannies from which they cannot escape” cost two Florida captives their lives, one a captive-bred intergrade—and the other an adult male Dusky Seaside Sparrow, representing 20% of that doomed subspecies’ entire population at the time. 

Voice: Where the species is common, the distinctive song of the Seaside Sparrow is one of the characteristic sounds of the summer salt marsh. Sonograms and slowed-down recordings reveal a variability and complexity inaudible to human ears , including clicking tremolos, glissando phrases, warblings, and buzzes. The field observer generally hears the primary song as a fast, dry tremolo followed immediately by a loud, broad buzz. The traditional comparison to the song of a distant Red-winged Blackbird is, like so many similar memory crutches, most helpful to birders who already know the Seaside Sparrow’s song. 

As might be expected given its disjunct populations over a wide range, this species reveals apparently considerable variation in songs. On the Atlantic Coast, northern birds are said to sing at a lower pitch than southern birds, which in turn may add whistled song elements more typical of Gulf Coast males. The Dusky Seaside Sparrow’s primary song, “very simple and mostly noise,” was decidedly insect-like, exceeded in that quality only by the song of the Cape Sable Seaside Sparrow, described by Hardy as two or three dry clicks, a very finely modulated buzz, and a thin concluding buzz quite unlike the broadly modulated, burry buzzes of coastal birds.

Like many other grass and marsh sparrows, Seaside Sparrows also have a longer, more complex song given primarily in flight. This vocalization is heard most often at the height of breeding, and is made up of a short series of introductory tsee notes followed by lower-pitched chips and concluding with a “condensed” version of the buzzing primary song.

Other than singing males, Seaside Sparrows are often quiet, but both sexes have a wide repertoire of calls. Agitated birds give a loud, low-pitched smacking chuk, often while perched at the top of a cordgrass stem. Flock members communicate, perched and in flight, with a short, high-pitched tsi, all attack with no decay; often repeated in an accelerating series of four or five notes, this call is easily overlooked as that of an insect. The most complex call is a whinny, given by both members of a pair, described as “a whirling, quavering” call often given together with a louder slurred chatter. 

Detailed description and measurements drawn from standard reference works

Adult Atlantic Seaside Sparrow maritima: Tail feathers grayish olive-brown with only faintly contrasting darker shafter streaks; outer tail feathers often more distinctly olive. Upper tail coverts and rump olive-brown, the feathers with narrow brownish black shaft markings creating fine, poorly organized streaks. Mantle and scapulars dull olive-gray, most mantle feathers with broad gray edges, aligning into blurry, irregular streaks. Short primaries nearly concealed on folded wing by secondary tips; both feather groups olive-brown with grayer edges, quickly wearing away. Tertials dark gray-olive with brownish shaft streaks and grayer edges, quickly wearing away. Greater and median coverts olive-brown with grayer edges; no wing bars. Marginal coverts of underwing pale yellow-green, creating a wing flash often visible on perched birds. Nape plain gray with only very fine darker gray streaking. 

Breast, sides of breast, and flanks dull medium-gray with faint, broad, blurry streaks formed by slightly darker feather centers and slightly paler feather edges; more solid gray appearance as feather edges wear. Undertail coverts, vent, and lower belly dull dirty white. Throat and chin bright clear white with no streaking; separated from broad white jaw stripe by poorly defined lateral throat stripe, concolorous gray with breast for most of its length but slightly blacker at the rear and as it approaches the bill. Gray crown, slightly darker than nape, with broad central stripe of olive-gray; very little contrast between gray of crown and gray of nape, rear supercilium, and ear coverts. Gray ear coverts with only faint blackish rear border; fade into white jaw stripe without clear demarcation by any whisker stripe. Lore and front of supercilium, from front of eye to bill, yellowish, fading behind eye to olive-gray and gray. Long bill slightly swollen at base, with curved culmen; blue-gray below, blackish gray above. Long, sturdy tarsi and toes muddy gray, with large, coarse scales often producing a gnarled appearance.     

Juvenile (maritima): Browner above and yellower below than adult. Rump and mantle feathers with larger black centers and broader gray edgings, creating clearer, better defined streaks. Scapulars blackish-brown with pale gray or whitish edges creating scaled effect. Primaries and secondaries browner than in adult; tertials blackish with crisp pale gray edges almost meeting at feather tip. Greater and median coverts dark brown with grayish edges and very thin, ephemeral pale tips, producing extremely inconspicuous wing bars. Nape brown-gray with fine blackish streaking.

Breast, sides of breast, flanks, and undertail coverts yellowish buff with neat blackish shaft streaks. Vent and belly dull dirty white. Throat and chin white tinged faintly yellowish with no streaking; separated from broad yellowish-white jaw stripe by pale gray lateral throat stripe. Rather dark gray crown with fine black streaks continuing onto nape. Ear coverts dull olive-gray; jaw stripe reaches around ear coverts to nape, forming yellowish-white ear surround. Lore and front of supercilium variably creamy to gray; gray rear of supercilium concolorous with crown. Forehead darker gray. Bill pinkish-gray above and below, darkening above with age; pale pink corners of mouth often retained for several weeks after fledging. Tarsi and toes muddy gray, with large, coarse scales. 

Length 139-141 mm (5.4-5.6 inches)

Wing chord 58-63 mm (2.3-2.5 inches)

Tail 54-55 mm (2.1-2.2 inches)

W:T 1.15