Species, Age and Sex Identification of Ducks Using Wing Plumage

Northern Pintail

Sex Determination

The speculum is at least partly iridescent green (rarely purple) on males and a dull non-iridescent bronze or rarely non-iridescent green on females. The underwings of most males are flecked to vermiculated; those of a few males and all females are barred. Male adult and first winter tertials are long and gray and the innermost has a wide marginal black stripe. The tertials of females are shorter and more brownish and lack the black stripe. Immature tertials of both sexes are similar and somewhat like those of adult females. Vermiculated scapulars are found only on males, but unvermiculated scapulars may be present on both males and females.

Tertials and scapulars are useful for identifying some males, but not for separating the sexes in all cases.

Age Determination of Males

The most useful character for separating the ages is the condition of the middle coverts. These have light edging on immatures and often appear narrow, and frayed. Some of these feathers persist throughout the hunting season. On adult males, these feathers are not frayed and generally plain. About one wing in 20 shows faint light edging, but the general aspect of these is such that they can readily be identified as adults.

The tertial coverts of the immature plumage have conspicuous edging which is a light yellowish brown. Birds with such wings are immature males. Tertial coverts of the adult-type lack edging and are found on both adult and immature wings. Tertials that lack the black edging are immature. It seems likely that wings with new tertials growing after November are immatures.

Age Determination of Females

The middle coverts of the immature plumage are rather narrow and somewhat trapezoidal. Any barring of these feathers is largely made up of triangular patches at the feather edge. The middle coverts of adults are broad and rounded and any barring is made up of variable shaped patches recessed from the feather's edge.

The tertial coverts of the immature plumage are very frayed, often poorly edged and individual feathers are often long and narrow. The tertial coverts of adult-type plumage are not very frayed, are well rounded, and have conspicuous edging.

GIF-Common middle covert markings of female northern pintail

Wing Character	Male		Female
	Adult	Immature	Immature	Adult
Scapulars	Vermiculated or barred or both		Barred
Underwing	Gray; heavily flecked with white		Alternate brown and white bars
Speculum	Iridescent green		Non-iridescent; bronze or (rarely) green
Tertials	Acutely pointed; brownish gray; without edging; black longitudinal stripe surrounding rachis	Brown; most distal with broad black stripe; others with pale stripe near rachis; often frayed	Brown with pale longitudinal stripe near rachis; well edged with pale color; often frayed	Bluntly pointed; dark brown; heavily edged with light brown; outer webs with brownish longitudinal stripe; sometimes slightly frayed
		After molt: Similar to adult male	After molt: Similar to adult female
Greater tertial coverts	Entirely gray; mat be somewhat frayed; broadly rounded	Gray with pale edging; somewhat trapezoidal in shape; often frayed	Brown with pale edging; pointed; often frayed	Brown; well marked with pale edging forming a smoothly rounded arc
		After molt: Similar to adult male	After molt: Similar to adult female
Middle and lesser coverts	Gray; without edging; sometimes heavily marked with light flecks; rounded	Gray; light brown edging at tips; sometimes lightly flecked; somewhat trapezoidal	Brown with light edging; often with paired triangular marking merging with edging; somewhat trapezoidal	Brown with light edging; often with paired internal oblong markings separated from edging; rounded

JPG-Underwing patterns of male and female northern pintails

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