oi ras 
Airs)" 
FALCONIDEH, DIURNAL BIRDS OF PREY.—GEN. 158. 213 
158. Genus FALCO Linnezus. 
* Tarsus more or less feathered above, elsewhere irregularly reticulate in small 
pattern; 2d quill longest; 1st alone decidedly emarginate on inner web. 
Jerfalcon, or Gyrfalcon. Tarsus feathered fully half-way down in front, 
with only a narrow bare strip behind, and longer than middle toe; 1st quill 
shorter than 3d. Upward of 2 feet long; wing about 16 inches; tail 10. 
White, with dark markings much as in the snowy owl; or, ash-colored with 
numerous lighter bars; young striped longitudinally beneath. An arctic 
falcon, of circumpolar distribution, in this country reaching the northern 
states in winter. It is split into several varieties which, however, do not 
seem to be strictly geographical, and concerning which ornithologists are 
singularly agreed to disagree. In var. candicans, the white predominates 
over the dark markings, and the bill and claws are white; N. Greenland ; 
Iceland; Arct. Am. and Eur. Avp., i, 81, pl. 19; Exxior, pl. 30; Cass. 
in Bp., 18. In var. islandicus, dark markings predominate, and the bill and 
claws are dark; the crown is lighter than the back, and the dark maxillary 
patches are slight; S. Greenland; Iceland; N. Eur. and Am.; 8S. to U.S. 
in winter. Cass. in Bp., 13; Exuior, pl. 31. Var. gyrfalco is like the 
last, but with the crown darker than the back, and the moustaches heavy. 
Other strains are sometimes recognized by name. See Newton, Proc. 
Phila. Acad. 1871, 95; Rine@way, ibid. 1870, 140; Barrp, Trans. Chicago 
aver ls iy (0 6 De) SAGER (Horst. 1772). 
Lanier Falcon. Tarsus fonthered a third way down in front, broadly bare 
behind, and longer than middle toe; 1st quill shorter than third. <A foot 
and a half ices wing 13-14; tail 7-8. Above, plain brown, the feathers 
bordered with rusty, ine nape, forehead and superciliary line white; below, 
white, with brown maxillary patches and other streaks on the breast and 
belly, the flanks barred; tail barred and tipped with whitish; adult with 
yellow iris and yellowish legs; young with brown iris and bluish legs. 
Western United States and southward; E. to Illinois (Sargent, Ridgway). 
F. polyagrus Cass., Ill. 88, pl. 16; Bp., 12; Coop., 458. . MEXICANUS. 
Peregrine Falcon. Duck Hawh. Tarsus feathered but a very little way 
above in front, and not longer than the middle toe; 1st quill not shorter 
than 3d. Size of the last, or rather 
less. Above, blackish-ash, with 
more or less evident paler waves ; 
below, and the forehead, white with 
more or less fulvous tinge, and 
transverse bars of blackish; con- 
spicuous black cheek-patches. 
Young with the colors not so in- 
tense, tending rather to brown; the 
tawny shade below stronger, the lower parts longitudinally striped. North 
America; generally distributed, not abundant. /. peregrinus WILS., ix, 
Fic. 141. Peregrine Falcon. 
