94 PACIFIC COAST AVIFAUNA No. 10 



leucophrys and Hylocichla g. audiiboni. While the distinctive feature of the 

 southern mountain chains is, of course, the strikingly large element of Mexican 

 species, many of them distinctly subtropical, such as Cyrtonyx m, mearnsi, Dry- 

 abates ariBOnae, Peitcedramns olivaceus, Cardellina rubrifrons, Trogon amhi- 

 guns, and the numerous species of hummingbirds, there are besides these, many 

 others closely related to southern California forms. In this class may be men- 

 tioned Strix o. huachitcae, Melanerpes f. aculeatus, Aimophila r. scotti, Pipilo f. 

 mesoleucus, Vireo h, stephensi, Sitta pygmaea, and Baeolophus i. griseus. Of 

 these the Strix, Aimophila, and Vireo are of peculiar interest, for although but 

 slightly distinguished from their California relatives, the habitats of the Pacific 

 Coast and Arizona representatives are so widely separated that there is no possi- 

 bility of their joining at any point. These birds must be treated as subspecies 

 rather than species on the ground of the sHght degree of difference between the 

 races, for they are resident wherever they occur, and from the manner in which 

 they are isolated in comparatively limited areas of Upper Sonoran and Transition 

 in the vast surrounding extent of Lower Sonoran desert, there is no possibility of 

 continuity of range with their closest allies. 



To sum up, it thus appears that the bird life of the higher mountains of Ari- 

 zona is a rather curious composite, of more northern Rocky Mountain forms ex- 

 tending southward, and of the southern, Mexican plateau forms extending north- 

 ward, the two faunas meeting, and to a certain extent interdigitating. Added to 

 these are other species, probably of southern derivation, closely allied to Pacific 

 Coast races but entirely isolated from them. Somewhat similar conclusions were 

 reached by Mearns in a paper on the avifauna of the mountains of central Arizona 

 (1890, pp. 45-50), but with an assumption of more continuous connection of the 

 Arizona mountains with the Sierras of central California than seems to exist. 



BIBUOGRAPHY 



List of Publications Relating to Arizona Ornithology 



The titles are arranged chronologically. I'nder each year the authors are 

 entered in alphabetical order, and the v/orks of each listed chronologically in or- 

 der of publication. The brief explanatory notes appended aim' to assist to a clear 

 idea of the scope and character of a book or paper when such is not apparent 

 from the title, and also to call attention to any point of particular interest in con- 

 nection Avith the present publication. 



1843. Gambel, W. Descriptions of some new and rare Birds of the Rocky 

 Mountains and California. < Proc. Acad. Nat. Sci. Phila., i, 1843, pp. 



259-262. 



1853. Woodhouse, S. W. Report of an Expedition down the Zuni and Colorado 

 Rivers, by Captain L. Sitgreaves, Corps Topographical Engineers. Accom- 

 panied by Maps, Sketches, Views, and Illustrations. Washington: Robert 

 Armstrong, Public Printer. 1853. 8vo, pp. 1-198, 77 pis., map. > Birds. 

 By S. W. Woodhouse, M. D. Pp. 58-105, pis. I, III-VI. 



