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Species, Age and Sex Identification of Ducks Using Wing Plumage

Black Scoter


The underwing of all ages and sexes is completely dark and unpatterned. Adult male wings are easily identified by the extremely attenuated outermost primary and the completely black upperwing. Adult female wings are dark brown. Their tertials normally have bluntly rounded unfrayed tips. Greater coverts are broadly rounded and unfrayed,often with poorly defined white areas near their tips. Wings of immatures of both sexes are a deep brown. Tertials are relatively short with frayed tips. Greater coverts are frayed and faded at their tips. Immature wings are about the same color as those of adult females. Although male wings are slightly larger than those of females, there is much overlap.

Wing Character Male Female
Adult Immature Immature Adult
Outermost primary Deeply attenuated for 55-60 mm. from the tip; shorter than adjacent primary Not attenuated but noticeably narrower and shorter than the next primary
Tertials Shiny black and acutely pointed; approximately 30 mm. longer than most secondaries Dark brown and sharply pointed; often faded at their tips Very dark brown and bluntly pointed; approximately 20 mm. longer than most secondaries
Tertial coverts Shiny black with rounded tips Dark brown; narrow slightly toward their tips which are usually slightly frayed and faded Dark brown; with rounded tips
Greater, middle, and lesser coverts Shiny black with rounded tips Dark brown; greater coverts often slightly faded near tips; appear rough Dark brown; may be faded at their tips


JPG-Adult male black scoter JPG-Adult female black scoter JPG-Immature black scoter

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