FAMILY FALCONIDA. — HAWKS, FALCONS, EAGLES, ETC. 167 
Fourth outer primary, decidedly notched; under surface of outer primaries, not 
heavily barred with dark brown and white; tail, less than 9.50; upper 
surface of tail, with distinct white bars. Red-shouldered Hawk. 
Buteo lineatus, and races. 
See No. 275. 
Under surface of primaries, heavily barred with dark brown and white; wing, 
under 11.50. Cooper’s Hawk. 
Accipiter cooper. 
See No. 267. 
Belly, white, without streaks or bars. Short=tailed Hawk. 
Buteo brachyurus. 
See No. 279. 
Belly, black; general plumage, black (black phase). Short-tailed Hawk. 
Buteo brachyurus. 
See No. 279. 
Group 4. Wing, 13 to 15 inches long. 
Section 1. Second primary, longest; first and second 
primaries, emarginate, or notched. 
Length, always under 193; primaries, hoary gray, without bands 
White-tailed Kite. 
Elanus leucurus. 
See No. 262. 
First primary, pale brown, with numerous bands on inner web; length, usually 
under 19 (some females are longer). Prairie Falcon. 
Falco mexicanus. 
See No.290. 
Length, always over 19; under tail coverts, spotted, or washed with dusky. 
Gray Gyrfalcon. 
Faleo rusticolus, and races. 
See No. 287. 
Length, always over 19; under tail coverts, white, without spots. White Gyrfalcon. 
Falco islandus. 
See No. 286. 
Section 2. Third primary, longest; face, bare. 
Basal portion of tail, white, barred with black, or brown; end of tail, black. 
Audubon’s Caracara. 
Polyborus che riway. 
See No. 297. 
