820 U.S. NATIONAL MUSEUM BULLETIN 237 paRT 2 



Confined as it is to the salt marshes of the Atlantic and Gulf coasts 

 of North America, the seaside sparrow is by far the most maritime 

 in distribution of all our land bu'ds. So rigidly is the species restricted 

 to its marsh habitat that its presence any distance from it is essentially 

 accidental. Practically the only times one ever sees it away from the 

 thick shelter of Spartina, Juncus, and other salt marsh grasses is 

 when, as WUson noted, storm-driven tides inundate the marshes and 

 force it to take temporary refuge on adjoinmg higher land. 



The 1957 A.O.U. Check-List recognizes nine distinct forms of the 

 seaside sparrow, which W. J. Beecher (1955) has postulated were 

 probably encouraged to develop by barriers in the form of drowned 

 rivers created by fluctuations in sea level during late Pleistocene 

 time. The nominate subspecies, breeding from Massachusetts 

 southward to Vii'ginia, is the northernmost race of this interesting 

 complex. In the spring and summer of 1955 I was able to study its 

 nesting habits in Ocean County, N.J., only a few miles north of 

 where Wilson first found it a century and a half ago, and where it 

 breeds side by side with the congeneric sharp-taUed sparrow. Unless 

 otherwise noted, the ensuing data are taken from my published 

 report (1956) 01 those studies. 



Spring. — Though a few individuals winter fairly regularly through- 

 out its breeding range, the northern seaside sparrow population is 

 essentially migratory, and most individuals winter to the southward. 

 Nothing is known of their departure from the wintering grounds in 

 spring, but Allan Cruickshank (1942) reports that in the New York 

 City region "while there is sometimes a light flight in mid-April, the 

 first widespread movement seldom comes before the initial week of 

 May. A spring peak is reached during the third week of this month." 



At Chadwick, Ocean Coimty, N.J., I saw the first seasides on 

 May 5, 1955, when several appeared on the territories where they 

 eventually nested. As these birds were not in evidence the previous 

 day, they had apparently arrived during the night. Durmg the 

 next two weeks the species was most abundant, as birds continued 

 to arrive and to pass by the territories being defended by the resident 

 males. 



Territory. — Unlike the closely allied sharp-tailed sparrow, the male 

 seaside sparrow establishes a nesting territory which he advertises 

 and defends against enroachment by other males. This he accom- 

 plishes mainly by singing, also by chasing when necessary. The song, 

 given from an exposed perch such as a cattail (Typha) stalk or marsh- 

 elder {Jva Jrutescens) bush within the territory, advertises its occu- 

 pancy and warns that other seaside sparrows will not be tolerated. 

 When the warning is disregarded, the male flies directly toward the 

 intruder, close to the ground and often uttering rapid chipping notes. 



