SONG SPARROW! SAN FRANCISCO BAY 1547 



more decidedly black, often scarcely rufescent on edges." The race 

 is depicted by Dawson (1923). 



Distribution 



Range. — -The Marin song sparrow is resident in the coastal district 

 of central California (exclusive of tidal and brackish marshes of San 

 Francisco Bay area), from interior Mendocino County (G miles south- 

 west of Laytonville), northern Sonoma County (Cazadero), and Lake 

 County (Blue Lakes) south through San Mateo and Santa Clara 

 counties to northern San Benito County (Paicines); east to the edge 

 of Sacramento Valley (Stonyford, Vacaville). 



MELOSPIZA MELODIA (Wilson) 



Song Sparrow: San Francisco Bay Marsh Subspecies* 



Contributed by Richard Fourness Johnston 



[Xowhere have song sparrows become adapted more interestingly 

 to a specialized environment than they have in the salt and brackish 

 marshes ringing San Francisco Bay. Here, as Joe T. Marshall, Jr. 

 (1948) has written, "the spatial isolation of different habitats, par- 

 ticularly bay salt-marsh from upland fresh-water growth is correlated 

 with a marked differentiation of very local races." Marshall's paper 

 analyzes the differences in the ecologies of these sedentary marsh song 

 sparrows, but their essential similarities have led to their being 

 grouped for present purposes. The race samuelis is selected to represent 

 the group because of Dr. Johnston's knowledge of it. A few details 

 regarding other races are inserted into the Johnston account; these 

 are set apart in brackets. — V.N.] 



Habits 



Melospiza melodia samuelis is one of the many distinctive morpho- 

 logical segregates of this widespread species found in the central 

 Calif ornian region. One of the smaller, darker subspecies (Marshall, 

 1948), it is closely restricted to a peculiar habitat-type found 

 only on the salt marshes fringing the northern reaches of San Fran- 

 cisco Bay. As these marshes are inhabited by no other subspecies, 

 any song sparrow seen there is almost certain to be M. m. samuelis. 



The salt marshes of the north part of the bay are flat expanses 

 of alluvial soil seldom more than 7 feet in elevation above mean sea 

 level. They are exposed to a varying amount of wetting each day 



* The following subspecies are discussed in this section: Melospiza melodia 

 maxiUaris Grinnell, M. m. samuelis (Baird), and M. m. pusillula Ridgway. 



