HAWKS, EAGLES, AND KITES 289 
b. Wing over 10° 00. 
b!. Second primary longest. 
b%, Tail generally over 9°00. 
63. Lower tail-coverts immaculate white. 
353. WHITE GYRFALCON. 
b4, Lower tail-coverts always more or less marked with dusky. 
54. Gray GyRFALCON and Races. 
c*. Tail under 9°00. 
c, Tarsus shorter than middle-toe without nail, upperparts 
blackish. . . i . . . 356. Duck Hawk. 
ce’. Tarsus longer than middle-toe without nail, upperparts 
brownish . A . 355, Prarrre FALcon. 
. Third or fourth primary longest. 
oe Upper tail-coverts white . . . . . . 3831. Marsa Hawk. 
c3. Upper tail-coverts brownish . . . 834. GosHawk (Im.). 
B. Outer primary generally one color, base sometimes whitish or with 
a few imperfect bars. 
a. Tarsus entirely bare, scales on its front large, rounded. 
62. AUDUBON’S CARACARA. 
b. Tarsus not entirely bare. 
b!. Tarsus entirely feathered . . 348. FeRRuGINOUS ROUGH-LEG. 
ec. Tarsus partly feathered. 
c, Scales on front of tarsus, small, rounded. . . 364. Osprey. 
d@, Scales on tarsus not rounded, square. 
d3, Three outer primaries emarginate or ‘‘notched.’’* 
d4, Wing under 12°00. . 343. Broap-wincrp Hawk (Im.). 
d’, Wing over 12°00. . . . 342. Swanson’ 8 re (Im.). 
e3, Four outer primaries emarginate or ‘‘notched.’” 
a Upper tail-coverts pure white. . 331. vinsae Hawk. 
. Upper tail-coverts not pure white; wing under 13°50; lesser 
wing-coverts conspicuously margined with rufous. 
339. Rep-sHoULDERED Hawx (Im.). 
. Upper tail-coverts not pure white; wing over 13°50; lesser 
wing-coverts not Sonepigucrely margined with rufous. 
337. RED-TaAILED Hawk and races. 
2. Underparts with more or less numerous cross-bars. 
A. Front of tarsus with sharply defined scales. 
a. Scales on front of the tarsus reas, rounded. 
al, Wing under 15°00 . ts ae a . 856. Duck Hawk. 
a, Wingover15°00. ...... 362. AUDUBON’S CARACARA 
b. Scales on front of the tarsus sharply defined, transverse, more or less 
square. 
bo}. Four or five outer primaries emarginate or ‘‘notched.” t 
b?. Tail white at the base and tipped with whitish. 
330. EverciapEe Kite. 
63. Tail rufous, with aomevinies a black band near the end. 
337. RED-TAILED Hawk (Ad.) and Races. 
b4. Tail black or blackish, with four to six white or grayish cross- 
bars. . . 339. RED-SHOULDERED Hawk (Ad.). 
"339a. FLORIDA Rep-sHOULDERED Hawx (Ad.). 
b§. Tail 10°00 long, gray, with several indistinct blackish bands. 
334. GosHAWK. 
c. Three outer primaries emarginate or ‘‘notched.’’* 
ec, Tail with two or three broad whitish bars. 
343. Broap-wincep Hawk (Ad.). 
¢. Tail with numerous narrow, indistinct blackish bars. 
342. Swarinson’s Hawk (Ad.). 
* See Fig. 88. t See Fig. 87. 
