Species, Age and Sex Identification of Ducks Using Wing Plumage
Separation of Oldsquaw, Black Scoter, and Surf Scoter
Two Most Distal Primaries:
(a) 10th primary shorter than 9th primary and either black and attenuated, or gray-black and tapering but much narrower than 9th primary -- Black scoter(b) 9th primary is the longest, outerweb of this feather narrows near tip -- Oldsquaw
(c) 10th primary longest, all primaries are uniformly tapering -- Surf scoter
Previous Section -- Separation of Red-breasted and Common Mergansers
Return to Contents
Next Section -- Mallard
