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 l/cwis, 

 Tune 32, 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. Wm. 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 cliflFs; 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 



