Species, Age and Sex Identification of Ducks Using Wing Plumage

King Eider

This species occurs only casually in the more northern states of the Atlantic Flyway. Although common in Alaska, few are shot. Only a few wings from known-aged birds were available for study. Therefore, although the information presented here is probably reliable, it should be used with caution. At present, a serious problem with king eiders is the lack of a reliable method for separating females and immatures of this species from the same age and sex classes of common eiders.

Wing Character Male Female
Adult Immature Immature Adult
TertialsEntirely black, sharply curved, and acutely pointedVery dark brown, usually edged with pale brown at tips only; tips are rather sharply pointed, often frayed and/or notchedVery dark brown, slightly curved, and acutely pointed
Greater tertial covertsBroadly rounded and blackUsually narrowly edged with pale brown; often frayed at tipsBroadly rounded, very dark brown, broad pale brown edging
Greater secondary covertsBlack, often with some white tippingVery dark brown; many white-tipped; and similar to those of adult femaleVery dark brown, many white-tipped; rest solid brown slightly faded at tips
Middle and lesser covertsEntirely white except for the leading edge of the wingSimilar to adult female but edging is darker and somewhat narrowerBroadly rounded, very dark brown, broad pale brown edging

JPG-Adult male king eider JPG-Adult female king eider JPG-Sub-adult male king eider JPG-Immature king eider

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