Species, Age and Sex Identification of Ducks Using Wing Plumage

Wood Duck

Sex Determination

The white trailing edge of the secondaries on females is much wider on the outer webs than on the inner webs. On males, this white edge is approximately the same width on both webs. On females, the first secondary proximal to these white-edged feathers is washed with black on the outer web. Males have no black on this feather.

Age Determination of Males

Immature tertials are pale bronze with pointed, usually frayed, tips. Immature tertial coverts are narrow and yellow-green. Most immatures replace both tertials and tertial coverts with dark blue adult-type feathers by late October. As the immature middle and lesser coverts are replaced by the adult-type plumage, the presence of a few dark blue feathers among the duller coverts indicates immaturity. Usually, the dark blue does not extend onto the third row of coverts and is much restricted to the area anterior to the proximal half of the secondaries. Generally, coverts of adults are somewhat wider and tend to lie more smoothly on the wing and the dark blue usually extends on to the third row of coverts and extends farther distally than on wings of immatures.

Age Determination of Females

Immature tertials are pale bronze with pointed, usually frayed, tips. Immature tertial coverts are narrow and yellow-green. Most immatures replace both tertials and tertial coverts with purplish red adult-type feathers by late October. Usually, the blue iridescence is confined to two rows of coverts and is restricted to the proximal half of the immature wing. Adult coverts are somewhat wider and tend to lie more smoothly on the wing. Dark blue usually extends onto the third row of coverts and extends farther distally than on the immature coverts.

Note:

By mid-fall, some immature wood ducks hatched in the southern United States appear to have replaced all of their immature upper-wing coverts. Their wings cannot be distinguished from those of adults.

Wing Character	Male		Female
	Adult	Immature	Immature	Adult
Secondaries	Dull iridescent blue; tip edged with approximately the same amount of white on both inner and outer webs		Dull iridescent blue; tip edged with white much more widely on outer webs than on inner webs, usually forming "tear drop"
Tertials	Same length as secondaries; most distal purple on outer web to feather edge		Same length as secondaries; most distal purple or yellowish on outer web but margined with dull blackish
	Others: Dark iridescent blue- black; second most distal white-edged at its tip	Others: Bronze-colored pointed with frayed tips		Others: Bronze- colored with rounded tips
		After molt: Similar to adult male	After molt: Similar to adult female
Greater tertial coverts	Broadly rounded; dark blue	Small narrow yellowish to green; often very frayed		Longer than other greater coverts; purple and yellowish with dark square ends
		After molt: Similar to adult male but usually darker than surrounding coverts	After molt: Similar to adult female
Other upperwing coverts	Greater and middle coverts same color as tertial coverts; bluish color extends anteriorly over three or more rows of coverts	Greater coverts and middle coverts paler than blue tertial coverts; bluish color often confined to two rows of coverts nearest secondaries	Greater coverts often iridescent only on outer webs; blue usually confined to two rows of coverts anterior to secondaries	Greater coverts usually iridescent on both webs; blue extends anteriorly over three or more rows of coverts

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