168 NORTH AMERICAN BIRDS EGGS. 



353. White Gyrfalcon. Falco islandus. 



^^^Mmte^ Range. Arctic regions; south in 



winter casually to northern United 

 States chiefly on the coast. 



Gyrfalcons are large, strong, act- 

 ive and fearless birds, about 23 

 inches in length. Their food con- 

 sists chiefly of hares, Ducks and 

 Waders which abound in the far 

 north. The present species is snowy 

 white, more or less barred with 

 blackish brown on the back and 

 wings and with a few marks on the 

 breast. They nest upon the ledges 

 of high cliffs, laying three or four 

 eggs of a buffy color, blotched and 

 finely specked with reddish brown, 



[Buff.J this color often concealing the 



ground color. Size of eggs, 2.30 x 

 1.80. In America, they nest in Greenland and the Arctic regions. 



354. Gray Gyrfalcon. Falco rusticolus. 

 Range. Arctic regions; south in 



winter to northern United States. 



This species is of the size of the last 

 but the plumage is largely gray, barred 

 with dusky. They nest more abund- 

 antly in southern Greenland than do 

 the preceding species. The nesting 

 habits and eggs do not differ. 



354a. Gyrfalcon. Falco rusticolus 

 gyrfalco. 



Range. Arctic regions; south cas- 

 ually to Long Island. 



This sub-species is hardly to be dis- 

 tinguished from the preceding; Its 

 nesting habits and eggs are identical, 

 the nests being of sticks, lined with weeds and feathers' and placed upon the most 

 inaccessible ledges of cliffs. 

 3545. Black Gyrfalcon. Falco rusticolus obsoletus. 



Range. Labrador; south casually, in winter, to Long Island. 



A slightly darker variety. Eggs indistinguishable. Data. Ungava coast, 

 Labrador, May 25, 1900. Nest a heap of seaweed and feathers on sea cliff. 3 

 eggs secured by an Esquimau who was lowered to the ledge by a rope. 



355. Prairie Falcon. Falco mexicanus. 



Range. United States west of the 

 Mississippi, and from Dakota and 

 Washington southward to Mexico. 



This species abounds in suitable lo- 

 calities, generally placing its nests up- 

 on rocky ledges and cliffs, and some- 

 times trees, generally upon the banks 

 of some stream. The nests are masses 

 of sticks, lined with weeds and grasses. 

 The three or four eggs have a reddish 

 buff ground color, and are thickly 

 sprinkled and blotched with reddish 

 brown and chestnut; size 2.05 x 1.60. 

 Data. Obispo Co. Gal., April 6, 1901. 

 Nest in a "pot hole" in face of limestone 



[Reddish buif.1 



[Buff. 



