WHITE GYRFALCON. 



Falco islandus. 



Char. Prevailing color white, often immaculate, but usually with 

 dark markings. Legs partially feathered. A sharp tooth near point of 

 upper mandible ; the end of under mandible notched. Length 2i to 24 

 inches. 



Nest. Usually on a cliff ; roughly made of sticks, — large dry twigs. 



Eggs. 3-4 ; buff or brownish, marked with reddish brown ; 2.25 

 X 1-25. 



GRAY GYRFALCON. 



Falco rusticolus. 



Char. Prevailing color dull gray, with whitish and slaty-blue bands 

 and spots; sometimes white prevails ; thighs usually barred 



