Species, Age and Sex Identification of Ducks Using Wing Plumage

Surf Scoter

All surf scoter wings are dark and unpatterned on both upper and under surfaces. Only adult males are black. Wings of all other sex-age categories are dark brown. Among these, adult females can be identified by their broadly rounded tertials and greater coverts over both secondaries and tertials. On immature birds, tertials are pointed and usually frayed and faded at their tips, and greater coverts over both secondaries and tertials are quite narrow and have frayed and faded tips.

Wing Character Male Female
Adult Immature Immature Adult
PrimariesOutermost primary similar to and as long as or longer than the adjacent primary
Outer webs blackOuter webs dark blackish brown
TertialsShiny black and bluntly pointed; approximately 20 mm. longer than most secondariesDark brown and pointed; may be faded at their tipsVery dark blackish brown; tips bluntly pointed; usually less than 20 mm. longer than most secondaries
Tertial covertsShiny blackDark brown; noticeably narrower than those of adults; often faded at their tipsVery dark blackish brown; smoothly rounded tips
Greater, middle, and lesser covertsEntirely black; appear smoothDark brown; most greater coverts are faded at their tips; they often appear roughVery dark blackish brown; some are slightly faded at their tips; all appear smooth

JPG-Adult male surf scoter JPG-Adult female surf scoter JPG-Immature surf scoter

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