312 NATURAL HISTORY OF BIRDS. 



tinguished by its very dark coloring, the lower parts being occasionally almost as 

 deeply tinted at all ages as the upper." 



The habits of all these forms are, so far as known, essentially the same. They are 

 birds of the Arctic regions, .and even in winter do not wander far southward. Hoi- 

 boll states that in Greenland they prey mostly on waterfowl and ptarmigans, nest in 

 inaccessible cliffs in January (!), and lay eggs similar in color to the ptarmigans, but 

 twice as large. MacFarlane, however, who found many gyrfalcons nesting in the 



FIG. 147. Falco lanarius, lanner. 



neighborhood of Anderson River, says that, out of eighteen nests found, all were in 

 trees except two, one of which was built on a ledge of rocks and the other on the 

 ground on the side of a steep hill. The earliest nest found with eggs was on May 

 10 ; but at that time the ground was still covered with snow, and the weather was 

 very cold. The eggs are described as varying much in general color and marking, 

 but are usually of a reddish or yellowish brown, due to the fine and even spotting of 

 these tints on a lighter ground. Heavy spots and blotches are unusual in these eggs. 



