1016 U.S. NATIONAL MUSEUM BULLETIN 237 pakt 2 



which in many sections is the only plant association occupied. [It] * * * occurs 

 sparingly in baccharis and artemisia [californica] brush to northward and also 

 is found in brush growing on sand dunes and mesas near seacoast, and in mixed 

 brush and cactus patches in arid washes. Within the brush cover the birds 

 find all requirements for existence: forage beat on the ground and low in the 

 bushes, nest sites at low levels in concealing twigs, and avenues of escape by 

 running through the bushes or by flight through or over their tops; this form is 

 less given to running long distances than are A. b. canescens and A. b. nevadensis, 

 perhaps because of the denser brushland habitat it selects. 



Because of the dense habitat and the general tendency of the species 

 to run behind and beneath bushes, this race is even more difficult to 

 detect than those occurring inland. Except when singing, most of 

 the time the birds stay below the tops of the brush, but they may 

 occasionally be flushed as one breaks through the cover or they may 

 be seen by squeaking them up, whereupon they briefly occupy look- 

 out posts on the tips of the chamise. 



Although the song and notes of this race do not differ from those 

 of the other sage sparrows, its darker coloration and smaller size 

 make it recognizable in the field. In mixed postbreeding groups 

 along the eastern border of the range of A. b. heUi in San Benito 

 County, I have been able to distinguish it readily from canescens in 

 the same flocks. The back is deep brown, contrasting but slightly 

 with the black taU, and the moustache marks and breast spot are 

 black and thick and large; also the sides are conspicuously striped. 



Grinnell and Swarth (1913) studied this sage sparrow in spring 

 and summer at the eastern edge of its range in the San Jacinto Moun- 

 tains of southern California. Here it was first noted at an altitude 

 of 3,000 feet on the west side. At Kenworthy, 4,500 feet, "the birds 

 frequented the denser growth of sagebrush on the floor of the valley. 

 During the first week in June flocks of five or six individuals were 

 occasionally encountered, possibly non-breeding birds, for the major- 

 ity of the species were in pairs and scattered through the brush at 

 fairly regular intervals. The birds forming flocks were silent, usually 

 feeding on the ground, while of the paired birds the male spent a 

 large portion of the time perched upon a projecting limb of a bush, 

 and uttering his song at frequent intervals." 



On the north side of the mountains these sparrows were fairly 

 common in the chamise of the hills above Cabezon. 



In late summer upslope movement was conspicuous and juveniles 

 were taken as high as 9,000 feet at Round Valley. As in other races of 

 sage sparrows, the annual molt starts early; in this case adults were in 

 midmolt in the latter part of June. Near the northern end of the range 

 of A. b. belli in western Tehama County, Calif., on June 12, 1 found pairs 

 closely spaced in Adenostoma 3 feet in height. The brush was re- 

 covering from a burn and one could move about easily in it in the 



