712 U.S. NATIONAL MUSEUM BULLETIN 237 part 2 



no Savannah Sparrows have been found breeding between the type 

 locality of rufofuscus (Babicora, Chihuahua), the White Mountains 

 of Arizona (Springerville and Big Lake), and the mountains of central 

 northern New Mexico (Taos and Lake Burford). Approximately 

 400 miles separate the Chihuahua breeding birds from the birds of 

 central eastern Arizona and approximately 375 miles separate the 

 Arizona colony from the birds apparently breeding in New Mexico. 

 Thus it would appear that over that part of its range which lies in the 

 southwestern United States and northern Mexico the Savannah 

 Sparrow breeds only in very local, isolated areas." 



Distribution 



Range. — Arizona, New Mexico, and Chihuahua. 

 Winter range. — Winter range unknown; recorded casually from 

 Jalisco (Ocotlan) and western Texas (east to Fort Clark). 



PASSERCULUS SANDWICHENSIS ALAUDINUS Bonaparte 



Coastal Savannah Sparrow 

 Contributed by Richard F. Johnston 



Habits 



Compared to other subspecies of Savannah sparrow, this coastal, 

 marsh-inhabiting savannah sparrow is relatively small and dark. It 

 maintains populations in two main types of habitat in coastal Cali- 

 fornia: the Salicornia association of tidal marshes and the grassland 

 associations of the coastal fog belt. The grassland habitats are 

 ordinarily not extensive in any one place, being found chiefly on 

 ridges of the coastal hills and mountains; grasslands today are not 

 found in broad conjunction with salt marshes, though perhaps they 

 were before extensive human modifications of the habitats took 

 place. 



The populations of this Savannah sparrow inhabiting salt marshes 

 are the best known. Ecologic distribution of the sparrows on salt 

 marshes is nearly limited to the broad expanses of low-lying salicornia 

 (Salicornia ambigua) on the older and higher parts of marshes; on 

 San Francisco Bay marshes these reaches stand about five to ten feet 

 above mean sea level and lie back of that salt marsh vegetation 

 (cordgrass, Spartina Joliosa) best suited to frequent submergence by 

 tidal flooding (R. F. Johnston, 1956). It is in this lower marsh 

 region that the song sparrows Melosjpiza melodia samuelis and M. m. 

 pusillula live; these and Savannah sparrows do not overlap signifi- 

 cantly either in breeding territories or in foraging beats. There 

 seems to be no competition between the two species for any environ- 



