FALCONS, CARACARAS, ETC. 
303 
gether unpleasant, resembling somewhat that of Sea Gulls, but near- 
by it is grating and suggests a maniacal laugh.” Dr. William L. Ralph 
writes in Bendire’s ‘Life Histories’: “The cry of the male is a loud and 
clear cac-cac-cac, quite different from that of the female — so much so 
that I could always recognize the sex of the bird by it; the call of the 
latter is more harsh and often broken.” 
The conspicuous white head and tail of adults of this species render 
it easy of identification even at a considerable distance. Young birds 
too closely resemble Golden Eagles to be distinguished with certainty, 
but the rarity of that species in the east makes it probable that any 
Eagle observed is a Bald Eagle. 
36. Family Falconxd;E. The Falcons, Caracaras, Etc. 
It is resemblance in structure rather than in habit which places the 
members of the genera Falco and Polyborus in the same family. In the 
former, predatory bird-life reaches its highest development; in the latter, 
we have birds not distantly removed from Vultures in the character of 
their food. From the great Arctic Gyrfalcons, nearly two feet in length, 
to the Indian Pygmy Falcon, no longer than a Song Sparrow, the Falcons 
are keen winged, dashing, fearless hunters among birds. They have not 
the soaring habits of the Buteos, from which they may be distinguished 
by their more pointed wings and more rapid wing-stroke. Their nests 
are less bulky than those of our buteonine Hawks, the eggs in some 
species being laid on the bare rock or in a hollow tree. (For Key see 
antea under Buteonidce.) 
353. Falco islandUis Brunn . White Gyrfalcon. Legs, and usually 
under tail-coverts, always white, unmarked. Ads. — Head white, finely 
streaked with black; scapulars, inter scapulars, and wing-coverts white 
with broad bars or semi-lunes, rarely guttate spots of slaty fuscous; tail 
sometimes wholly white, usually broadly or narrowly barred with slaty 
fuscous; underparts white, with sometimes a few small grayish spots or 
streaks. Im. — Similar, but upperparts brownish gray with white margins 
and broken bars; tail barred with brownish gray; underparts more heavily, 
sometimes uniformly streaked. L., 22*00; W., 16*00; T., 10*00; B. from N., 
*95. 
Remarks. — The white, unmarked under tail-coverts and prevailing white 
color will distinguish this bird from any form or phase of Falco rusticolus. 
Range. — Arctic regions. Resident in Greenland; in winter casual s. 
to Out., N.' S., and Maine. 
Nest, on rocky cliffs. Eggs, 3-4, varying from creamy white, spotted or 
blotched with cinnamon-brown, to uniform pale reddish brown, spotted 
or blotched with shades of the same color, 2*30 x 1*85. Date, Umanak, 
Greenland, May 26 (Thayer Coll.). 
“The food consists of waterfowl and other birds — largely of vari- 
ous arctic species of Grouse which are captured on the wing. All these 
northern Falcons were formerly esteemed for hawking, as they still 
are by the Mongol races; their style of flight is magnificent — much 
swifter than that of the Peregrine — and both are deadly ‘footers’ 
(i. e., tenacious of grip), but they lack spirit and dash” (Saunders). 
