g42 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 2 



include black rush or needle grass (Juncus roemerianus) and sand rush 

 (Fimbristylis castanea) . From a sparrow's-eye view (or a marsh wren's 

 for that matter) a most important component of the salt-meadow 

 vegetation is a small shrub called honey mangrove {Avicennia nitida) , 

 which provides these marsh-dwelling passerines much-favored cover 

 both in Louisiana and in some parts of the Texas coast (Brooks, 1933). 

 In some areas marsh-elder {Iva) bushes are also important (Griscom 

 and Nichols, 1920). In coastal Mississippi Burleigh (1944) states: 

 "One of its requirements during the breeding season seems to be the 

 presence of clumps of sharp-pointed rushes (Juncus) in which to nest. 

 Where this growth is lacking in stretches of salt marsh that are other- 

 wise suitable, the species occurs only in rather limited numbers during 

 the winter months." 



Neither the Louisiana nor the Texas seaside sparrow has been the 

 subject of an extensive hfe history study, but I was able to make some 

 observations on breeding individuals of fisheri at the race's type 

 locality. Grand Isle, La., in April 1960. Consequently the following 

 incomplete life history deals mainly with^^en, with the few squibs 

 of information available on sennetti incorporated here and there. 



Territory. — In the early morning of Apr. 15, 1960, I mist-netted 

 and color-banded a breeding pair of seaside sparrows in a salt grass- 

 honey mangrove association on Grand Isle. I placed red plastic bands 

 on the male (subsequently called Red) and yellow bands on the female 

 (called Yellow). The female showed a fuU-sized vascular-edematous 

 brood patch, the male no sign of such a patch; both appeared to be in 

 the light color phase. I watched the activities of this pair and of some 

 of their neighbors on April 15-17 and again on April 30 and May 1. 

 A grid of stakes set out in the march at 20-pace intervals allowed me 

 to map individual movements and from these to work out the extent 

 of each bird's territory. 



The size of the area the banded pair utiUzed in the mid-April period 

 was 1.7 acres, most of it grassy. About 15 to 20 percent was strips 

 or scattered patches of knee- to breast-high mangrove, and about 

 10 percent consisted of salt-water pools and narrow sloughs. As some 

 parts of the marsh were apparently Httle used by seaside sparrows, 

 the over-all population density seemed to be less than one bird per 

 acre. A transect census I ran later through 3,400 feet of suitable- 

 looking marsh yielded a rough estimate of 68 sparrows per 100 acres. 



An unmated male (called UB for unhanded) maintained a territory 

 to the south and west of Red's, and a pair, of which I saw very Uttle, 

 held another tract toward the south and east. I saw encounters 

 between the color-banded pair and UB a number of times. On 

 April 16, when Yellow's eggs had begun to hatch, I noted both Red 

 and UB in a mangrove bush near the territory border. They were 



