378 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



ing amount of body-feathers, tail, but not wings, are moulted from 

 Nov. to April, but apparently juvenile feathers are retained on 

 mantle and under -parts. Female. — A certain amount of adult 

 plumage is acquired, but juvenile feathers of lower-breast, portions 

 of mantle and wings are retained. Moult as in male. 



Second winter and summer. Male. — Birds with under -parts 

 browner than others may be in their 2nd year. 



Measurements and structure. — £ wing 240-256 mm., tail 75-84, 

 tarsus 40-43, bill from feathers on culmen 34-37 (12 measured). 

 $ wing 223-235, bill 35-38. Primaries : 1st narrow, pointed and 

 about two-thirds longest primary-covert, 3rd longest, 2nd about 

 as long, 4th 8-12 mm. shorter, 5th 22-26 shorter, 6th 34-40 shorter ; 

 2nd slightly emarginated on inner web in ad. $, ad. $ has 2nd 

 broader than in <$ and less emarginated, juv. $ 2nd slightly narrower 

 than in adults. Innermost secondaries pointed at tip and longest 

 longer than 6th or 7th primaries ; long scapulars pointed at tip. 

 Tail cuneate with 14 stiff, pointed feathers. Bill about same height 

 and breadth at base, depressed and flattened towards tip where it 

 is narrower but rounded ; upper mandible in ad. <J with a basal 

 protuberance with convex and descending outline, lateral base 

 bulging with basal outline convex, in ad. $ culmen not appreciably 

 elevated at base, bulge at lateral base of bill scarcely marked ; in 

 juv. $ and $ there is no basal protuberance, and lateral bulge is 

 hardly apparent, but in juv. £ it commences to develop in winter ; 

 nail large, broad but narrowed terminally. Feathers on fore -head 

 extending in a broad stripe nearly or quite as far as posterior end 

 of nostril, but those of lores not advancing beyond rictus. 



Soft parts. — Bill (ad. <J) upper mandible with square black 

 patch at base margined orange except in front, where there is a 

 patch of bluish-white extending to near nostrils, basal protuberance 

 deep reddish -orange lighter towards nail, shading to rich yellow 

 towards margins, nail dingy greyish-yellow, lower mandible flesh- 

 coloured, (ad. $) greenish-black, black spot at lateral base slightly 

 if at all indicated ; legs and feet (ad. <§) orange -red, webs dusky 

 tinged green, claws black, (ad. $) yellow- orange, webs greyish- 

 dusky, claws black, (juv. $ Nov.) dull orange, darker at joints and 

 back of tarsi ; iris (ad. $ and $) yellowish -white, (juv. <J) brown. 



Characters. — No subspecies. Black wing of adult male, black- 

 brown in female and immature birds, absence of white speculum 

 together with frontal feathering which extends forward consider- 

 ably along culmen (loral feathering not extending beyond rictus) 

 distinguish this species in all plumages. 



Field -characters. — Adult drake at once identified by conspicuous 

 white patch on nape. Plumage of duck varies greatly. When 

 nape -patch shows clearly no further clue needed but often this is 

 quite invisible in female, even through binoculars, and bird may then 

 easily be confused with females Common and Velvet -Scoters and 

 female Scaup. Though Common Scoter is smaller, size is always 



