74 
BIRDS OF COLORADO. 
332. Accipiter velox. Sharp-shinned Hawk. 
Resident; common. In migration is common throughout 
the State, and breeds throughout its range, but much more 
commonly in the mountains than on the plains. Breeds up to 
10,000 feet. C. F. Morrison took a set of eggs at Fort Lewis, 
Tune 22, 1886. 
333. Accipiter cooperi. Cooper’s Hawk. 
Resident; common. Breeds both on the plains and in the 
mountains to about 9,000 feet. Along the main range of the 
mountains it is not so common as the Sharp-shinned Hawk. 
Dennis Gale found eggs at Gold Hill June 25 and young July 2. 
334. Accipiter atricapillus. American Goshawk. 
Resident; not uncommon. Is rather more common in 
winter than in summer. In winter it occurs throughout the 
State below 9,500 feet; in summer the few that remain are 
restricted to the mountains, breeding from 9,000 to 10,000 feet. 
334a. Accipiter atricapillus striatulus. Western Goshawk. 
Winter visitant; rare, if not accidental. Most of the nu- 
merous records of the occurrence of the Western Goshawk in 
Colorado really refer to the eastern form, which is the common 
Goshawk of this State. The only certain record of the western 
form is that of Prof. Win. Osburn, who says: “A male of this 
species was captured at Arkins, February 26, 1889, and a female 
at the same place, March 5. The male was much darker than 
the female with finer markings on the under parts, correspond- 
ing to the description of variety striatulus.''^ (Science, XXII. 
1893, 212.) This is the Pacific Coast Goshawk coming east 
regularly to Idaho. 
337a. Buteo borealis kriderii. Krider’s Hawk. 
Resident; not uncommon. There is a slight question yet 
as to the distribution of the three varieties of Red-tailed Hawks 
that occur in Colorado. It has been taken for granted that all 
the records of typical borealis for Colorado should be referred to 
some of the other forms, though it is not unlikely that it may 
rarely visit the extreme eastern portion of the State. There 
can be no doubt that Krider’s Hawk occurs on the plains in 
Colorado during migration, and the present writer feels sure 
that the record of its nesting there is also correct. F. M. Dille 
reports that it nests on plains and large cliffs; one nest in Weld 
County was taken May 24. Of the occurrence and breeding of 
Krider’s Hawk in the mountains there is more question. It 
probably does occasionally visit the eastern foothills of the main 
range, but there is as yet no unquestionable record of its nest- 
ing above 6,000 feet. 
