474 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. IX. 



tree, but more commonly on a rocky cliff. The eggs are from two 

 to four, dull white or washe'd and marked with brown. They meas- 

 ure about 3 x 2.35 inches. 



Genus HALLEETUS Savigny. 



166. Haliaeetus leucocephalus (LINN.). 

 BALD EAGLE. 



Distr.: North America from northern Mexico to British Columbia 

 and Ungava (a subspecies occurs in Alaska), breeding throughout its 

 range. 



Adult: Tarsus, not entirely feathered as in the Golden Eagle; 

 head, neck and tail, white; general plumage, dark brown; primaries, 



Bald Eagle. 



black or blackish; bill and feet, yellow; iris, yellow. The sexes are 

 similar but the female is larger than the male. The adult does not 

 assume the perfect white head and tail until the third year. 



Immature (first year) : Very dark brown, the bases of the feathers, 

 white, and showing more or less in the plumage; bill, black; iris, 

 brown; feet, yellowish. 



