1018 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 2 



Measurements of 40 eggs show an average of 18.93 millimeters in 

 length and 14.48 millimeters in width. These dimensions are not 

 significantly different from those for the race canescens, but, again, 

 the eggs are significantly shorter than in the large-sized race nevadensis. 



Plumages. — The pattern of markings is similar to that in the north- 

 ern sage sparrow, except that the dorsal striping is obsolete and the 

 flank striping is augmented ; the moustache markings and breast spot 

 are broader, larger, and more solidly black. Coloration is much 

 darker as follows: above, deep brownish slate-gray, becoming browner 

 on back; wings and tail dull blackish, with light brown edgings, the 

 middle and greater coverts indistinctly tipped with pale brownish 

 buffy or pale wood brown; outer web and small tip area of outer tail 

 feathers buff; the sides and flanks are buff to light brown streaked 

 with dusky. 



The Juvenal plumage of A. h. belli is of the same pattern as in 

 nevadensis, but the coloration is darker, corresponding to the darker 

 colors to be seen m the adult plumage. 



Food. — On May 26, near Beegum, Tehama County, I took a female 

 that was carrying four green caterpillars crosswise in her bill. These 

 were % inch long and were of a species prevalent in the Adenostoma 

 brush at that time. This food was obviously intended for young 

 birds, but in an adult taken at the same place on June 12, I found a 

 similar caterpillar m its stomach as well as sand and some fragments 

 of seeds. 



In the summer and fall periods of warmth and drought, Bell's sage 

 sparrows come to water as do the related races of this species. John 

 Davis writes of the "Bell Sparrows" at Hastings Reservation in the 

 Carmel VaUey, Calif., coming to water traps on November 5. This 

 is a time when available water is about at the low point for the year. 

 He has seen the species in faU at water sources well removed from its 

 normal habitat, and apparently the birds must range some distance 

 for water at this dry season. 



Voice. — The notes of this race are like those of the northern sage 

 sparrow, although the song may be variously described. GrinneU and 

 Storer (1924) write one variation of it as tweesitity-slip, tweesitity-slip, 

 swer. Near Coulterville, Calif., on May 12, they recorded a bird 

 singing every 9 or 10 seconds, each song lasting 2% seconds. The song 

 would be repeated for several minutes from one perch and then the 

 bird would change to another location. "It would perch on the top- 

 most shoot of a greasewood [Adenostoma] bush, facing away from the 

 wind, its feathers blown outward somewhat, and would rock back 

 and forth in keeping its balance on the swaying twig." This bird 

 centered its attention on a particular section of a hOlslope and "circled 

 about within a radius of not over 150 feet, singing from one perch, 



