1314 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 3 



To my ear the song patterns of the California populations of 

 mountain white-crowned sparrow are quite distinct from those of 

 Gambel's sparrows wintering in California or breeding in the parts of 

 Alaska where I have studied them. This correlates with Anne H. 

 Wing's statement (pers. comm.) : "The fact that the range of individual 

 Gambel's sparrow songs heard at Johnson's Crossing, Yukon Territory, 

 did not exceed a major fifth interval is interesting in the light of the 

 fact that similar songs heard from white-crowned sparrows in the 

 Rocky Mountain National Park (oriantha) containing the same note- 

 names often ranged through more than an octave." 



As one illustration of how color characters normally confined to one 

 group of races may crop up in the other, Austin L. Rand (194S) 

 describes an adult female collected in fall migration at Shoal Lake in 

 southern Manitoba that had a pink bill, pale gray breast and belly, 

 white bend of the wing and black lores combined with an olive brown 

 rump, olive-toned edgings to the feathers of the upper parts, and 

 heavily pigmented flanks. The black lores is referable to Z. I. leuco- 

 phrys, the general color of the upper-parts and flanks is "very similar 

 to those of pugetensis from the British Columbia coast/' and the bill 

 color and bend of wing is referable to either Z. L leucophrys or Z. I. 

 gambelii. 



To sum up, racial differences in morphology are slight, and in many 

 cases cannot be used as sole criteria to differentiate between races. 

 Differences in behavior and song pattern are more marked, and 

 therefore whenever possible should be used in addition to the morpho- 

 logical characters. Physiological differences, such as extent of 

 prenuptial molt, amount of subcutaneous fat, and date of recrudes- 

 cence of the gonads, are even more reliable criteria, but only in spring. 

 Discussion of these lies outside the scope of this article. The locality 

 of observation or collection, while important, gives only a partial 

 clue to the identity of a given individual, for the winter ranges of 

 several races overlap, and the breeding ranges of some are contiguous. 

 Therefore the more characters one can scrutinize — morphologic, 

 behavioristic, physiologic — the more reliable will be the identification. 

 Intermediate individuals should be given no racial designation. 



While the vagueness of the differentiating characters and their 

 fluidity of distribution may be disconcerting to persons accustomed 

 to less plastic species, they are the most fascinating properties of 

 this interesting bird. The lack of trenchant racial differences and the 

 abundance of intermediate individuals indicates the close relationship 

 of all members of the species and, presumably, the recency of the 

 evolutionary development of the present races. 



Enemies. — I interpret the term "enemies" in its broadest sense, 

 to include both native and introduced predators, parasites, and man 



