DESCRIPTION 



The dusky seaside sparrow is about 15 cm 

 long. Adults have black or blackish brown upper 

 parts, edged with grayish olive, white venter with 

 heavy black streaking, bright yellow on lores and 

 at bend of wing. The wings and tail are fuscous to 

 fuscous black, edged with light yellowish olive. 

 The sexes are similar. 



Juvenal plumage is lighter in color with nar- 

 rov/er tan streaking, and reduced yellow on lores 

 and wings. 



Color plates appear in Howell (1932), Peter- 

 son (1947), Sprunt (1954), and Trost (1968). 

 A black and white photograph appears in Eber- 

 hart(1968). 



RANGE 



The dusky seaside sparrow is a sedentary 

 inhabitant of brackish marshes and savannahs in 

 northern Brevard County, Florida. The 1978 

 survey of singing males documented their pre- 

 sence in the St. Johns River Basin at the following 

 three locations: St. Johns National Wildlife 

 Refuge, approximately 1 km south of the refuge, 

 and between the north and south forks of the 

 BeeHne Highway (Baker in press). The sub- 

 species is isolated from other populations of sea- 

 side sparrow by 120 km to the north, 200 km to 

 the west, and 400 km to the south (Trost 1968). 



Dusky seaside sparrows were formerly abun- 

 dant in Indian River salt marshes on Merritt Is- 

 land, from Dummitt Creek south to Banana Creek 

 (Trost 1968). Sharp (1968) determined the main- 

 land distribution to be from Salt Lake south near- 

 ly to Florida Highway 520 and between 1-95 and 

 the St. Johns River. 



RANGE MAP 



Critical habitat and 1977 range are indicated 

 on the following page. The dusky seaside sparrow 

 apparently no longer occurs on Merritt Island (J. 

 Baker, personal communication). 



STATES/COUNTIES 



Florida: Brevard. 



HABITAT 



The species inhabits salt marshes with highly 

 fluctuating water levels and salinities. It prefers 

 moist zones dominated by cordgrass {Spartina 

 bakerii), 3 to 5 m above mean sea level. The St. 

 Johns River marshes present a savannah-like 



aspect, being dotted with small ponds, salt pans, 

 cabbage palms (Sabal palmetto), and hammocks 

 (Sharp 1968, 1970; Baker 1976;DSSRT draft). 



Sharp (1968, 1969a, 1970) believes zones of 

 short and tall interdigitating plants form the pre- 

 ferred microhabitat. The Merritt Island habitat 

 was composed of a heterogeneous mosaic of the 

 tall cordgrass and black rush (Jiincus roemerianus) 

 with short saltgrass {Distichlis sptcata), saltwort 

 {Batis maritima) and glasswort {Salicornia peren- 

 nis). In the St. Johns River savannahs, fires and 

 varying salinities and water levels produce the tall- 

 short pattern with cordgrass. 



Black and white habitat photographs may be 

 found in the following: diked salt marsh-Eberhart 

 (1968); former Merritt Island habitat— Baynard 

 (1914) and Nicholson (1928); St. Johns River sa- 

 vannah—Sharp (1969b). 



FOOD AND FORAGING BEHAVIOR 



The subspecies is largely insectivorous. Six 

 stomachs contained 37% grasshoppers and crick- 

 ets and 25% spiders. Other items included miscel- 

 laneous insects, seeds, and tubers (Howell 1932). 

 Trost (1968) observed duskies feeding on small 

 snails, a dragonfly larva, a butterfly, and possibly 

 ants. 



They forage at or near the ground (Baker 

 (1976, in press). Feeding has been observed on 

 dikes and in tidal zone (Trost 1968). 



SHELTER REQUIREMENTS 



The dusky sparrow remains concealed in 

 dense vegetation during the nonbreeding season 

 (Trost 1968). Glasswort on Merritt Island (Bay- 

 nard 1914) and cordgrass in the St. Johns flood- 

 plain (Sharp 1968, Baker 1973) form the pre- 

 ferred shelter. 



NESTING OR BEDDING 



The dusky seaside sparrow constructs a cupped 

 nest from grasses. Nests are placed in tussocks 

 2 to 35 cm above ground and may be covered 

 with arched vegetation (Nicholson 1928). 



Nest sites include tussocks of glasswort, black 

 rush, cordgrass, salt grass, and wire grass (Sporo- 

 bolus virginicus) (Baynard 1914; Nicholson 1928, 

 1929; Trost 1968). Baker (in press) reported a 

 nest in a salt bush (Bacharis angusti folia). 



Baynard (1914) and Nicholson (1928) present 

 black and white photographs of nests and nest 

 sites on Merritt Island. 



