BIRDS OF COLORADO. 125 



759. Turdus aonalaschks. Dwarf Hermit Thrush. 



^ Migratory; rare. The exact position of this bird in Colo- 

 rado.is not yet definitely settled. The prevailing form of Hermit 

 Thrush is auduboni^ but there is a mounted specimen of the 

 typical Dwarf Thrush taken at Fort Collins the first day of 

 October. H. G. Smith at Denver has taken one May 13, 1887, 

 and one September 26, 1884, both identified by Ridgway, and a 

 third that probably should be referred to this form was taken 

 there October 5, 1892. These records make it sure that this 

 form extends regularly during spring and fall migration as far 

 east at least as the western edge of the plains. Concerning those 

 sent to Mr. Ridgway, he says: " Not quite typical, being a little 

 larger than the average, but are much' too small for auduboni 

 and altogether too gray and too slender-billed for pallasii.'''' 

 (Nidologist, in. 1896-7, 76.) 



759a. Turdus aonalaschkae auduboni. Audubon's Hermit 

 Thrush. 



Summer resident; common. Sometimes called the Rocky 

 Mountain Hermit Thrhsh because it is common and characteristic 

 of that region. The most eastern record is that of Capt. P. M. 

 Thome and it is fairly common a few miles nearer the foothills 

 during migration. Arrives the last of April and leaves the 

 plains the last of May. Breeds in the mountains from 8,000 

 feet to timber-line and occasionally to the lower foothills. At 

 the lower altitude in southern Colorado laying begins early in 

 June and is continued on the mountains to the middle of July. 

 Returns to the lower parts in September and leaves the ^ State 

 about the middle of October. 



759b. Turdus aonalaschkae pallasii. Hermit Thrush. 



Migratory; rare. From the east the true Hermit Thrush 

 comes only to the eastern edge of Colorado, thus just touching 

 the range of audoboni. Two young-of-the-year were taken 

 September 26, 1885, by Capt. P. M. Thome at Fort Lyon, and 

 identified for him by Mr. Brewster. ■ 



761. Merula migratoria. American Robin. 



Summer resident; not common. The robins of Colorado 

 shade from nearly pure migratoria on the plains of eastern Col- 

 orado to typical propinqua. There is no definite dividing line 

 between the two forms, and for two hundred miles east of the 

 Rocky Mountains, birds are often found that are a fair inter- 

 mediate between the two forms. Birds that can be reasonably 

 assigned to the eastern form occur as far west as the base of the 

 foothills, and V. L. Kellogg mentions taking Robins in Estes 

 Park that were as bright as specimens from eastern Kansas. It 



