942 U.S. NATIONAL MUSEUM BULLETIN 23 7 paet 2 



misidentification. After my failure to note these sparrows on my first day ashore 

 on Santa Rosa, I searched specially, exploring the most suitable places and 

 squeaking for them, as I had done successfully on Santa Cruz. Not one could be 

 found. I am led to think that if Howard was not actually mistaken, they are 

 rare and certainly not a dominant resident on Santa Rosa, in spite of the presence 

 of suitable habitat. 



Immediately subsequent to A. H. Miller's visit to Santa Rosa 

 Island, Egmont Z. Rett (1953) stayed there from Mar. 15 to 28, 1951 

 and especially searched areas up to 4 miles inland for Aimophila 

 ruficeps but found none. Some sort of competitive interaction between 

 the song sparrows and rufous-crowned sparrows on these two islands 

 is thus rather strongly suggested. WiUiam Leon Dawson (1923) 

 found rufous-crowns abundant on Santa Cruz Island in the spring 

 of 1915 but writes "prickly pears are very abundant on Santa Cruz 

 Island, and * * * the birds frequent the thickest patches. They are 

 reaUy very ungetatable, if you please." 



Nesting. — James G. Cooper (1887) long ago indicated for Ventura 

 County that rufous-crowned sparrows were found "on some islands, 

 where they doubtless breed." Despite their abundance on Santa 

 Cruz, however, no one seems to have published anything about the 

 nesting of this race. Alfred B. HoweU and A. J. van Rossem (1911) 

 reporting on their visit to Santa Cruz Island April 24 to May 2, 

 1911, write of the rufous-crown: "Rather common in suitable places. 

 One of the females of two pairs within fifty yards of camp, was in- 

 cubating when shot April 26, as the absence of feathers upon her belly 

 indicated." 



Young. — The only information I have been able to find for the 

 young of A. r. obscura is the comment by Frank A. PiteLka (1950) 

 that he found on Santa Cruz Island, Aug. 29, 1949, a "pair with at 

 least two bob-tailed fledgUngs no more than two or three days out of 

 the nest." 



Plumages. — Larry Wolf (MS.) reports no significant differences in 

 postjuvenal or annual adult molt in this race as compared with his 

 description herein of A. r. ruficeps. The juvenal plumage of A. r. 

 obscura averages darker than that of A. r. ruficeps, especially the breast 

 streaks; and the adult plumage is distinguished from the nominate 

 race by a generally darker coloration, the back feathers having darker 

 centers. 



Voice. — In his description of the song of this race, the only such I 

 have found, WilUam Leon Dawson (1923) suggests a possible difference 

 from that of birds of the nearby mainland, A. r. canescens. He -writes: 

 "On Santa Cruz Island, where I found the birds abundant in the spring 

 of 1915, I was deceived repeatedly by the chattering, vivacious, and 

 wren-Uke quahties of the Rufous-crown's song. Wee chee chit i wit 



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