Species, Age and Sex Identification of Ducks Using Wing Plumage
Mallard
Sex Determination
The white bar anterior to the speculum extends onto the greater tertial coverts on all female wings but terminates at the proximal edge of the speculum on nearly all male wings. Approximately 2-1/2-3 percent of males show some white edging on their tertial coverts. Adult males can be identified because the white is not continuous with that over the secondaries. Immature males with white over the tertial coverts are difficult to tell from immature females. The white bar is the easiest sex character to use, because of its high degree of reliability and the fact that it is rarely lost when a wing is detached.Vermiculated scapulars are found only on males. Early in the hunting season (September and October) many males possess barred scapulars which are remnants of their summer plumage.
Proximal underwing coverts are vermiculated or flecked on adult and most immature males. These feathers are barred on females and on a few immature males.
Age Determination of Males
Immature tertials are often frayed and faded, usually narrow, and lack the pearly color of adult tertials. By late November immature tertials are replaced by first winter tertials, identical in appearance to adult feathers. At the same time, immature tertial coverts may be replaced by coverts which are broader, unfrayed, and similar to adult coverts and thus differ from adjacent immature coverts, which have not been molted. Many immature males have light edging on the inner webs of the most distal primary coverts. Adult males do not show this character. Middle coverts of immatures are narrower and more trapezoidal than those of adults. Occasionally, these feathers on immature males are worn and/or have light edges. This type of edging does not occur on the middle coverts of adult males.Age Determination of Females
Tertials that are frayed and/or faded are remnants of immature plumage and are found only on immature ducks. Tertial coverts of immatures are often frayed, faded, and narrow, and the two most proximal often lack the white of the speculum bar. As with males, greater tertial coverts of immatures may be replaced. Conspicuous light edging on the inner webs of the four most distal primary coverts is found only on immatures. Adults may have minute or no edging on these coverts. Middle coverts of immatures tend to be narrow and trapezoidal, while those of adults are broadly rounded.
| Wing Character | Male | Female | ||
| Adult | Immature | Immature | Adult | |
| Scapulars | Vermiculated or barred or both | Barred | ||
| Proximal underwing coverts | Flecked to vermiculated | Barred | ||
| Sometimes barred | ||||
| Greater tertial coverts | Dull gray to reddish brown, no white edging | Brown, one or more with white edging | ||
| Tips form smoothly rounded arcs, rarely frayed or faded; edging usually broad extending well toward body | Tips generally slightly triangular to trapezoidal; often much frayed or faded | Tips form smoothly rounded arcs, rarely frayed or faded; edging usually broad extending well toward body | ||
| White edging often narrows proximally | ||||
| After molt: Similar to adult male | After molt: Similar to adult female | |||
| Tertials | Broad, pearly gray, no edging, rarely frayed or faded. My be growing in Oct. | Small, narrow, brownish, often frayed or faded near tips. Adult type feathers may be growing in Dec. or later. | Varies from pearlly gray to brownish, often light edging; rarel frayed or faded | |
| After molt: Similar to adult male | After molt: Similar to adult female | |||
| Middle and lesser coverts | Broadly rounded; solid gray to brown; no edging | Slightly triangular to trapezoidal; often frayed or faded; usually brown | Broadly rounded; brown; usually with light brown edging; sometimes no edging | |
| May have fine edging or no edging | Edging varies from conspicuous to absent | |||
| Primary coverts | No edging | Inner web of four most distal have light edging or no edging | Inner web of four most distal without edging to conspicuous edging | Inner web of four most distal have light edging or no edging |
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