1124 U.S. NATIONAL MUSEUM BULLETrN 23 7 tart 2 



diately to the south the northern Oregons outnumber the gray-heads, 

 mearnsi east and montanus west of the mountains. 



In the western part of the Avinter range of the species on the Kaibab 

 Plateau in northwestern Arizona, D. I. Rasmussen (1941) found that 

 "The most abundant birds found during the winter season in this 

 [pinon-juniper-woodrat] association are the juncos. The red-backed 

 junco [dorsalis], which breeds in the upper portions of the mountain, 

 is present in winter along with Shufeldt's junco [actually J. 0. montanus 

 (Miller, 1941b)], "with perhaps individuals of the pink-sided junco and 

 the gray-headed junco [J. c. caniceps]. Flocks of juncos were observed 

 in the snow-covered foothills in flocks of twenty-five to one hundred 

 individuals in the winter of 1930-31. Both the 'black heads' and the 

 'gray heads' were present. The former exceeded the latter in numbers 

 of three to one." 



At Grand Canyon National Park 2,476 juncos were banded from 

 October 1932 through February 1939. In round niunbers 60 percent 

 of these were J. 0. montanus (recorded as "Shufeldt's") and 40 percent 

 J. caniceps, plus four "pink-sided" and one slate-colored (totalhng 

 0.2 percent). Observations made at the same place 20 years later in 

 1956 and 1957 by Louise Hinchhffe and W. E. Dilley (MS.) found 

 montanus the most numerous junco, often 6 to 1 of the others, followed 

 by caniceps, including dorsalis and intergi'ades, and mearnsi in varying 

 numbers, with a few slate-colored and "Cassiar" juncos. Probably 

 at least ji of the gray-headed juncos banded at Grand Canyon were 

 caniceps-dor satis intergrades native to the vicinity. Records were 

 kept of the color of the upper mandibles of 23 banded in November 

 and December 1932. Miller (1941b) would probably have classified 

 10 of these as pure dorsalis, as the mandibles of six were enthely black 

 and those of four "mostly black" or "nearly all black." Six pre- 

 sumably were Miller's pure caniceps, the upper mandible of one haAdng 

 been recorded as "pink" and those of five as "very little black," 

 "practically no black," or "flesh-colored except black tip." The 

 mandibles of the other seven were intermediate in color, the birds 

 presumably being caniceps-dorsalis intergrades from the nearby 

 Kaibab Plateau population. 



In the San Francisco Moimtains southeast of the Grand Canyon 

 H. S. Swarth (1924b) found that "By the middle of October [1922] 

 caniceps was present in fair abundance, in the pinon-juniper belt to 

 some extent, but in greater numbers in the yellow pine belt. Flocks 

 of juncos were frequently encountered composed of as many as fifty 

 or sixty individuals. Nine-tenths of such a flock would consist of 

 caniceps and shujeldti [montanus] in about equal numbers, with a few 

 mearnsi and perhaps an occasional hyemalis'\ At Flagstaff a few 

 miles south, in 1935, L. L. Hargrave (MS.) recorded that a flock of 



