FALCO, 247 
2.08 X 1.63, creamy white, vinaceous-white, or pale vinaceous- 
buffy, sprinkled, speckled, or irregularly spotted with madder- 
brown. Hab. Western United States, east to eastern border 
of Great Plains (occasionally to Illinois), south into Mexico. 
355. F, mexicanus Scutze. Prairie Falcon. 
b’ Tarsus not decidedly longer than middle toe (without claw), often shorter; 
first quill longer than third. 
c'. First and second quills equal and longest; second with inner web 
slightly sinuated near tip; adult and young very different in color, 
the latter with stripes instead of bars beneath, and without bars on 
upper parts. Vest on cliffs or in hollows of giant trees. Eggs 3-5, 
2.20, or less, X 1.70, or less, varying in color from buffy to deep cin- 
namon- and hazel-brown, usually more or less broken into spotting 
or blotching, but sometimes nearly plain; spots varying from hazel- 
to rich madder-brown. (Subgenus Rhynchodon Nrrzscu.) 
a. Adult with top of head sooty black, or deep black, appreciably or 
decidedly darker than back; chest creamy buff, buffy white, or 
pure white, often immaculate, never very heavily spotted with 
blackish. Young with lower parts ochraceous or buffy striped 
with dusky, the feathers of upper parts bordered with buffy, 
ochraceous, or rusty. Male: Length 15.50-18.00, wing 11.30- 
13.00, tail 6.00-7.50, culmen .75-.80, tarsus 1.60-1.90, middle toe 
1.78-2.05. Female: Length about 18.00-20.00, wing 13.00-14.75, 
tail 6.90-9.00, culmen .85-1.00, tarsus 1.95-2.20, middle toe 1.95- 
2.30. 
e'. Adult with chest usually distinctly streaked with, or marked 
with tear-shaped spots of, blackish. Young paler, with 
ground-color of lower parts pale buffy or buffy whitish. 
Hab. Europe and portions of Asia. 
F. peregrinus Tunst. Peregrine Falcon.! 
é'. Adult with chest usually immaculate. Young more deeply 
colored, with ground-color of lower parts frequently deep 
ochraceous. Hggs 2.06 < 1.61. Hab. Whole of America, 
south as far, at least, as Chili; eastern Asia? 
356. F. peregrinus anatum (Bonar.). Duck Hawk, 
@. Adult with top of head dark slaty, or plumbeous-slate, uniform 
with back; chest heavily spotted with blackish, and dusky 
bars of remaining under parts very broad. Young with lower 
parts sooty black, streaked with pale buffy or buffy white, the 
feathers of upper parts without rusty margins. Male: Wing 
12.90-13.00 (12.95), tail 6.60-6.90 (6.75), culmen .80-.88 (.84), 
tarsus 1.88-2.00 (1.94), middle toe 1.88-1.95 (1.91). Female: 
Wing 14.50-14.75 (14.66), tail 7.70-8.00 (7.84), culmen .95-1.00 
(.96), tarsus 2.00-2.25 (2.16), middle toe 2.05-2.21 (2.13). Hab. 
1 Faleo peregrinus Tunst., Orn. Brit. 1771, 1. 
. 
