FALCONIDJE DIURNAL RAPTORES. 455 



Accipiter cooperi Bonap. 



COOPER'S HAWK. 



Popular synonyms. Stanley's Hawk ; Blue Chicken Hawk : Blue Hawk ; Blue Quail Hawk ; 

 Swift Hawk; Blue-backed Hawk; Blue Darter. 



Falco cooperi BP. Ann. Lye. N. Y. ii, 1826, 433; Am. Orn. i, 1828, pi. 10, fig. 1. 

 Astur cooperi Bp. 1838.-AUD. B. Am.i,1840,98,pl.24. 



Accipiter cooperi DEKAT, Zool. N. Y. ii, 1844. 18, pi. 4,flg. 5. CASS, inBaird'sB. N. Am. 

 1858. 16.-BAIBD. Cat. N. Am. B. 1859.No. 15.16.-CouE8. Key. 1872.112; Check List. 

 1874. No. 339; 2d ed. 1882, No. 495; B. N. W. 1874. 334.-Kn>aw. Nom. N. Am. B. 1881. 

 No. 431. 



Nisus cooperi SCHLEO. Rev. Ace. 1873, 73. B. B. & R. iii. 1874. 230. 

 Falco stanleyi AUD. B. Am. 1831. pis. 36,141; Orn. Biog. 1. 1831, 186. 

 Accipiter mexicanus Sw. P. B.-A. ii. 1831, 45. CASS. in Baird's B. N. Am. 1858. 17. 



BAIBD. Cat. N. Am. B. 1859, No. 16. 

 Nisus cooperi var. mexicanus B. B. & R. Hist. N. Am. B. iii, 1874, 231. 



HAS. Whole of the United States and table-lands of Mexico ; north in summer to New 

 Brunswick, the Saskatchewan, and Washington Territory; south, In winter, to Costa 

 Rica and Veragua; breeding throughout its United States range. 



SP. CHAB. Wing.8.70-11.00; tail, 7.80-10.50; culmen, 0.58-0.80; tarsus. 2.30-2.85; middle 

 toe, 1.45-1.85. Fourth or fifth quill longest; first equal to or shorter than tenth; outer 

 five with inner webs sinuated. Tail rounded. Tarsi usually distinctly scutellate. 



Adult. Above slate-color, varying from a fine bluish to a brownish cast, the shafts of 

 the feathers black. Pileum plumbeous black, the occipital feathers snow-white be- 

 neath the surface ; primaries plain brownish slate, their shafts clear brown. Tail nar- 

 rowly tipped with white, and crossed by four very regular, but sometimes not sharply 

 defined, bands of dusky, narrower than the slaty ones, the last broadest, the first nearly 

 obsolete, and concealed by the coverts, which are sometimes narrowly tipped with white. 

 Lower parts white and rufous, in transverse bars, the shafts of the feathers black, and 

 the rufous bars usually connected along the middle portion of the feathers; tibiae more 

 deeply colored, the rufous usually predominating; crissum immaculate white. Lining 

 of the wing white, irregularly spotted with deep rufous; inner webs of the primaries 

 with transverse bands of dusky and white anterior to their emargination and silvery 

 gray terminally, the dusky bands about seven in number on the longest quill, the two 

 colors nearly equal in width. Male. Slate of the upper parts of a fine bluish cast; nape 

 and sides of the head bluish ashy, the sides of the breast usually tinged with the same. 

 Wing. 8.85-9.40; tail, 7.80-8.30; culmen. .60-.68; tarsus, 2.30-2.60; middle toe, 1.45-1.55. 

 {Eight specimens.) Female. Slate of the upper parts of a brownish cast, nape and sides 

 of the head dull rusty brownish, the sides of the breast without ashy tinge. Wing, 10.00- 

 10.80; tail, 9.00-9.40; culmen. .70-.80; tarsus, 2.65-2.85; middle toe, 1.60-1.85. (Five specimens.) 

 (Colors in life. Terminal half of bill deep black, basal half pale blue; cere greenish yel- 

 low; iris deep orange-red; tarsi and toes deep lemon-yellow; claws deep black.*) 



Young. Above grayish brown, the feathers more or less bordered with rusty ; the 

 scapulars and upper tail-coverts with concealed white spots; the occiput blackish, with 

 the bases of the feathers white, and the pileum and nape streaked with rusty. Tail gray- 

 ish brown, tipped with whitish, and crossed by four bands of brownish black or dusky. 

 Lower parts white, longitudinally striped with clear dusky brown, the shafts black. 

 (Colors in life. Iris varying from greenish white to chrome-yellow; bill blackish ter- 

 minally, pale blue basally ; tarsi and toes varying from very pale greenish yellow to 

 lemon-yellow; claws slate-black.) 



*Fresh colors of an adult male killed January 16, 1867, at Mount Carmel, Illinois. 

 Length. 17 inches; extent, 30.50 inches. 



