RING-NECKED DUCK 183 



Iris bright orange-yellow. Bill, terminal part, about 10 mm. deep, jet black, including the nail. 

 Posterior to this is a band a little less than 10 mm. wide (narrowest in the middle) which is ivory- 

 white in color; remainder of bill, except a narrow white line all along the base of the culmen, dull 

 slate color. Legs and feet yellowish slate, darker on the joints and black on the webs. 



Wing 195-206 mm.; bill 45-49; tarsus 46. 



Weight 1 pound, 8 ounces to 1 pound, 12j ounces (0.68 to 0.80 kilograms). 



Adult Female: Occiput dark brown to blackish, much paler on the forehead. Sides of head and 

 neck gray, often mottled with blacker feathers. Region along base of culmen, chin and throat, much 

 lighter than sides of head, sometimes nearly white. Upper side of neck and mantle brown, the feathers 

 of the latter tipped with lighter brown. Scapulars like the mantle. Back, rump, upper tail-coverts 

 and tail black. Upper breast pale brown shading into the pure white of the abdomen. Flanks sandy 

 brown, lower abdomen shading into dusky. Under tail-coverts blackish and somewhat vermiculated. 

 Wing as in the male. 



Iris bright hazel or golden hazel; according to A. Brooks "yellow olive." Bill dark lead-color with 

 sub-terminal bar of white; tip of bill black. Legs and feet greenish gray, with the webs blackish; 

 about the same color as in the male. 



The adult female is very similar to the female of the European Pochard and of the Red-head. 

 From the former it may be distinguished by the absence of vermiculated pattern in the scapular 

 region, and by its grayer head and smaller size. From the latter it can be easily separated by its 

 darker color on the upper side as well as by its smaller size. Identification in the field is difficult, but 

 the white-banded bill of the female Ring-neck proves a useful mark. 



Wing 185-195 mm.; bill 43-46; tarsus 45. 



Weight about 1 pound, 6 ounces to 1 pound, 9 ounces (0.62-0.70 kilograms). 



Note: On the breeding grounds, in July, female specimens become very dark gray and mottled over 

 the whole abdomen. Whether all specimens exhibit this dark summer phase I am unable to say, but 

 it is interesting to note that the same phenomenon is seen in the Tufted Duck (Nyroca fuligula). 



Female in First (Juvenal) Plumage: Lower surface not white as in adult, but silvery gray, more or 

 less mottled and barred with brown, especially on the breast and lower abdomen. Upper surface very 

 similar to that of adult female. 



Iris bright golden hazel to dark hazel. Bill black to blackish, with indistinct bluish band near the 

 tip. Legs and feet same as in the young Red-head, light greenish gray. 



Mate in First (Juvenal) Plumage: Very similar to the female at corresponding age, but by Sep- 

 tember a few black feathers will probably be found on the sides of the face and neck, and the occiput 

 will be blacker. Remainder of plumage the same. 

 Iris usually more yellow than in the female. 



Immature Male: The change to adult plumage is very slow. The white face-marks are gradually 

 filled in with black feathers until the head becomes a dull black, with the neck gray. There is com- 

 paratively little change in the rest of the plumage all through the winter, and specimens almost like 

 those seen in October may be found in April. The under parts remain gray and mottled. Full plum- 

 age is probably seldom reached until the second winter. 



Male in Eclipse Plumage: Not exa min ed; but a definite summer plumage exists. 



Young in Down: (see Plate 59) Most nearly like the young of the Canvas-back Duck (Nyroca 



