^^o Henshaw on Birds observed in Nezv Mexico. [October 



hatches migrated at all. The observer is conscfous of a general 

 movement among the small birds, but it is difficult to tell whether 

 it is actual migration or not until certain evidence presents itself 

 in the arrival of species previously unnoticed. So, at least, it 

 was in the present case ; and the first supposed migrating visitor 

 was seen August 8 — a single Wilson's Flycatcher {Myiodioctes 

 pusillus) . Previous to this, however, there had been a move- 

 ment on the part of the Hummingbirds, which was disclosed by 

 the sudden departure of the males of Selasphorus platycercus* 

 which took place about August i, and constituted the first positive 

 evidence of the fall migration. 



After August 8 the tokens of a general movement on the part of 

 the birds became perfectly evident ; and soon flocks of birds from 

 farther north put in an appearance. At this time the birds, instead 

 of being scattered through the woods, according to the exigencies 

 of nesting, were gathered into large flocks, composed of the most 

 heterogeneous elements. Bluebirds, Nuthatches, Titmice, War- 

 blers, Creepers, Snowbirds, and Woodpeckers, all trooped through 

 the forest together, and where one moment reigned perfect silence, 

 the next was enlivened by a chorus of chirps and call-notes, the 

 signals by which the motley throng is held together in an ever 

 moving but united band. As the fall advanced, these flocks were 

 of less frequent occurrence and contained a smaller number of 

 species, as well as of individuals, until towards the end of October, 

 when they were composed mainly of Snowbirds, Nuthatches, and 

 such species as intended to winter not far away. 



The list pretends to be nothing but a record of our own obser- 

 vations, and whatever value it may possess will be derived mainly 

 from the fact that it contains no species but those actually seen, and 

 leaves those which were not seen to be added by the labors of 

 future investigators. 



i. Hylocichla ustulata swainsoni. Swainson's Thrush. Fairly nu- 

 merous in fall. First appeared September 13. 



2. Hylocichla unalascae. Dwarf Thrush. — Rare; in fall only. A 

 single specimen secured October 12. 



2 a. Hylocichla unalascae auduboni. Rocky Mountain Hermit 

 Thrush. — Numerous as a summer resident. The young were out of 

 the nest July 18. 



3. Merula migratoria propinqua. Western Robin. — Was not de- 

 tected breeding, although it probably summers here. Common in fall. 



4. Cinclus mexicanus. American Water Ouzel. — Numerous all 

 along the upper Pecos. By July 18, the time of our arrival, young birds 



