LIFE HISTORIES OF NORTH AMERICAN WILD FOWL 87 



by new feathers, snbteniiinally barred with the bhxck and tipped 

 with brown. In the fall the winter plumage is reproduced by a com- 

 plete new growth of feathers on the head and neck; the plumage of 

 the back and the breast is restored partly by molt and partly by 

 wearing away of the dark tips; the whole process is a beautiful 

 illustration of the maximum of concealment with the minimum of 

 molt. 



Mr. Millais (1913) says the young female can be distinguished 

 from the male, even in the downy stage, being " generally darker 

 on the under parts and the eye stripe narrower and shorter." In 

 the juvenal plumage she has a "smaller eye stripe, paler upper parts 

 and darker upper breast." The young female remains largely in 

 the juvenal plumage through much or all of the first winter; speci- 

 mens collected in February show the molt into the first spring plum- 

 age in various stages; but by March most of the birds have ac- 

 quired a semiadult plumage. In this the dull-brown feathers, with 

 narrow sandy-brown edges, of the juvenal plumage have been re- 

 placed by the dusky or duslcy-barred feathers, with broad edges of 

 deeper and richer browns, of the adult plumage. But birds in this 

 plumage can always be distinguished from adults by their juvenal 

 wings, which still retain the old, worn, dusl^ secondaries, tertials, 

 and long scapulars; the long, curved, brown-edged tertials and the 

 v.hite-tipped secondaries and secondary coverts of adults are lack- 

 ing; the belly plumage also remains largely immature. At the 

 next summer molt, which is complete, a second winter plumage is 

 assumed, which is nearly adult; but the white tips of the second- 

 aries and secondary coverts are smaller and narrower; and the 

 birds are usually more heavily barred above and more uniformly 

 dark broAvn below. At the next molt, when a little over 2 years old, 

 the fully adult plumage is acquired. Some females probably breed 

 during their second spring, but probably most of them do not do 

 so until they are nearly 3 years old. 



The foregoing account of the molts and plumages of this species 

 will suffice equally well for the American eider and the Pacific 

 eider, as the sequence is the same in all three species, or subspecies, 

 and the immature plumages of all three are practically indistin- 

 guishable. 



Food. — Eiders obtain their food almost wholly by diving to 

 moderate depths; almost any kind of marine animal life is accept- 

 able and easily digested in their powerful gizzards; most of it is 

 found on or about the sunken ledges or submerged reefs off rocky 

 shores, which support a rank growth of various seaweeds and a pro- 

 fusion of marine invertebrates. They jn-efor to feed at low tide 



100449—2.5 7 



