Gyrfalcons 213 



distinction is found in the fact that only a single quill (the outermost) has the 

 web emarginated. Of these birds we may first mention the White Gyrfalcon 

 (F. islandus], a bird about twenty-three inches long, which is found exclusively 

 in the circumpolar regions. The adult is mainly white, but with the head and 

 hind neck often narrowly streaked with dusky, and the upper parts more or less 

 barred or transversely spotted with slate -dusky. It is an extremely shy bird, 

 and when sitting with its pure white breast toward the intruder will often escape 

 detection on the snow. It flies well, with rapid beats of the wings, followed by 

 a short sail, and frequents rocky coasts where great numbers of water fowl are 

 nesting, feeding largely upon them, as well as upon Ptarmigan and other birds. 

 Our knowledge is at present rather limited as to its nesting habits, but so far as 

 known the nest is usually placed on a rocky ledge. It was found by the Polaris 

 Arctic Expedition near Cape Hays in latitude 79 44' north, where it was breeding 

 on cliffs. The Gray Gyrfalcon (F. rusticolus] is a bird of the extreme northern 

 portions of Europe, Asia, and North America, including Iceland and southern 

 Greenland. It is slightly smaller than the last, and, while light colored, has the 

 upper parts everywhere more or less distinctly barred with bluish gray and 

 dusky. Its habits are similar to those of the white species, and similarly it 

 nests on inaccessible cliffs along the seashore. The eggs are said to be three or 

 four in number and creamy w r hite, spotted and blotched with reddish brown. 



Closely allied is the Gyrfalcon (F. rusticolus gyrfalco) of northern Europe 

 and Arctic America from northern Labrador and the coasts of Hudson Bay to 

 Alaska. It is a slightly darker bird than the last, while the Black Gyrfalcon 

 (F. r. obsoletus] of Labrador is still darker. In winter this bird comes south to 

 Canada, Maine, and New York, but it is common only in its northern home. 

 Like the other forms mentioned this one also nests on high cliffs, the following 

 description of a nest being from the pen of Mr. L. M. Turner, who found them 

 nesting on the Chapel, an immense rock three hundred feet high with precipitous 

 and nearly inaccessible sides, near Fort Chimo, Ungava. He says: "I went 

 with a party of four to lower me over the cliff to secure the eggs which might 

 remain in the nest. I descended to the nest. In front of it huge icicles stood 

 joined with the slightly projecting roof above the ledge ; some of these ice columns 

 were two or three inches thick and four inches wide, forming an icy palisade 

 around the edge of the nest and permitting approach to the interior only by a 

 narrow space or doorway next the main wall of rock, and I was compelled to 

 detach the ice before I could reach the four eggs I saw within the nest, which 

 was composed of a few twigs and branches of larch and spruce, irregularly dis- 

 posed on the outer side of the rim of the nest to prevent the eggs from rolling out, 

 forming only a semicircular protection, while the rear portion was a part of 

 the bare rock of the ledge. Below these twigs were the remains of former nests." 



The Prairie Falcon (F. mexicanus] inhabits the western United States from 

 the eastern border of the Great Plains to the Pacific, and from the northern boun- 

 dary southward into Mexico. It is a bird from seventeen to twenty inches long, 

 the adult being pale grayish brown above, indistinctly but broadly barred with 

 pale clay-color or bluish gray, while the lower parts are white, with the flanks 



