30 DISTRIBUTION OF THE DWARF THRUSH 



variety ; yet it does not necessarily follow that the true Hermit 

 Thrush is never found so far south. I should not leave this 

 subject of the southerly distribution of the Audubon Thrush 

 without calling attention to the fact that it constitutes one of 

 the few exceptions to the general rule that southern repre- 

 sentatives of a species are smaller than the others; its larger size 

 being unaccountable on any premises we at present command. 

 The distribution of the Dwarf Hermit in latitude agrees with 

 that of its eastern relative. This bird is the prevailing, if not 

 the exclusive, form in the Pacific region, from Alaska as far 

 north at least as Sitka and the island of Kodiak, to the ex- 

 tremity of the peninsula of Lower California. Though it is par- 

 ticularly attached to the immediate Pacific slopes, it yet 

 spreads eastward to the Eocky Mountains. Dr. J. G. Cooper 

 found it in the Colorado Valley, probably at Fort Mojave, 

 where he was stationed for some time as a medical officer 

 of the Army. I occasionally saw it in the mountains of Central 

 Arizona, and within a year or two Mr. H. W. Henshaw has 

 observed it still further eastward, in Southern Arizona, and 

 amongthe headwaters of the Gila in New Mexico. These advices 

 clearly show that the limit of eastward dispersion assigned 

 by Mr. Ridgway (the valley of the Humboldt River in Nevada), 

 must be considerably enlarged. As to the movements of the 

 species within the general area it inhabits, the accounts 

 which have reached us are perplexing ; yet they may, I think, 

 be adjusted, if we exercise due care. It is evident from Dr. 

 Cooper's researches, that the Dwarf Hermit winters in lower 

 portions of Arizona, a fact which both Mr. Henshaw's observa- 

 tions and my own would conlirm, were this necessary ; and its 

 occurrence at Cape St. Lucas shows probably the southernmost 

 point reached at this season.* Starting from these and corre- 

 sponding latitudes, the bird migrates to Alaska, as already inti- 

 mated, and breeds at the northernmost points it reaches. The 

 limit of the breeding-range in the other direction remains to be 

 determined, for it is pretty certain that Dr. Cooper, in speak- 

 ing of nests which he found at Santa Cruz, and supposed to 

 belong to the Dwarf Thrush, was mistaken. He describes the 

 nests as placed " about five feet above the ground ", and says 

 that they contained speckled eggs, neither of which statements 

 agrees with what we know of the nidification and color of the 

 eggs of the Hermit Thrush. Dr. Brewer has alluded to these 

 discrepancies, which his great familiarity with the subject ena- 



