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Species, Age and Sex Identification of Ducks Using Wing Plumage


Immature greater coverts are narrower, squared, often frayed to a point over the tertials with an indistinct pale tip over the secondaries. During the hunting season, immature birds occasionally replace both their immature tertials and greater tertial coverts with adult-type feathers. For a given sex, these new feathers are indistinguishable from those of adults but differ markedly from other immature greater and middle coverts which are retained. With practice, redheads can be aged primarily by the appearance of their tertial coverts. Several combinations are possible: 1) immature-type tertial coverts always indicate an immature bird but sex is best determined from other coverts; 2) adult male or adult female-type coverts similar to the surrounding coverts indicate an adult of that sex; 3) adult male or adult female-type tertial coverts that differ from the surrounding immature-type coverts indicate the sex of some immature birds.

Wing Character Male Female
Adult Immature Immature Adult
Tertials Usually taper to a rounded point; some well vermiculated Usually frayed to a sharp, ragged pint; without flecking or vermiculation Usually taper to a rounded point, without flecking or vermiculation
After molt: Similar to adult male After molt: Similar to adult female
Greater tertial coverts Broad, smoothly rounded and flecked or vermiculated Appear narrow, and usually have ragged pointed tips Broad, smoothly rounded without flecking or vermiculation
After molt: Similar to adult male After molt: Similar to adult female
Middle and lesser coverts Broadly rounded; may vary from entirely vermiculated to lightly flecked Often narrow somewhat toward tips; tips often appear notched Broadly rounded and entirely plain to faintly flecked near their tips
Flecking may vary from conspicuous to barely discernable Entirely plain

JPG-Adult male redhead JPG-Adult female redhead JPG-Immature male redhead JPG-Immature female redhead

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