Drew on Birds of San Juan County , Colorado. 
FIELD NOTES ON THE BIRDS OF SAN JUAN 
COUNTY, COLORADO. 
BY FRANK M. DREW. 
In the southwestern portion of Colorado, and lying wholly 
within the Rio Colorado basin, is the little* county of San Juan. 
With the exception of Baker’s Park and tributary gulches, San Juan 
is composed of mountain peaks, fully one-third of the county being 
above timber-line. (For a good description of the Park and ad- 
jacent country, see F. B. Rhoda’s account in Hayden’s Report for 
1874.) The average elevation of the Park is 9,500 feet ; the low- 
est part of the county is at the extreme southern end, in the 
Animas Canon. Here it is about 8,500 feet, and for a short dis- 
tance up this narrow gorge runs a tongue of vegetation entirely 
different from the characteristic flora of San Juan. This different 
growth is composed of pines, poplars, and scrub oak and maple 
bushes. The flora of the county is essentially western and boreal. 
The peaks are the homes of such sub-arctic mammals as La- 
gomys princeps , Arctomys faviventer , Lepus americanus 
bairdi , all in great abundance, as well as Erethizon epixanthus , 
Ovis montana , Felis concolor , Neotoma. cinerea , and others. 
But one reptile — a snake — was seen ; neither batrachians nor 
fishes were found. Owing to the peculiar topographical position 
of the county, the list becomes of a little more interest than a 
mere faunal paper, as it is composed of those birds which range 
to, or above 10,000 feet. My observations extend from June, 1879 
to January, 1881. The nomenclature is, in the main, that of 
Dr. Coues ; that is, in so far as I have been able to keep up with 
recent revisions. 
1. Tardus migratorius propinquus, Ridg. Western Robin. — 
Very common ; breeds, the nest being placed indifferently two feet from 
the ground in bushes, or twenty-five feet up in trees. One nest which I 
found was curiously placed in some willow bushes in much the same man- 
ner as the nest of a Red-winged Blackbird, being supported entirely by 
the sides. How the bird made a start is a puzzle to me. If climatic 
changes have caused such a marked hoariness — a bleached color — in 
Parus atricapillus septentrionalis , why has climatic variation bleached 
the white out of the robin’s tail and left it nearly or quite black? The 
birds are found here from April until the last of November and occasion- 
al lv rear two broods. 
