Species, Age and Sex Identification of Ducks Using Wing Plumage

Key to Duck Species

From each pair of contrasting statements choose the one that best describes the wing in hand. Each choice leads to an additional choice until the species is identified. For example, a wing described by statements 1 (b), 6(a), 7(a), 8(a), and 9(a) is that of a mallard.

1.Upper wing: primaries, secondaries, tertials, and their coverts: all an unpatterned black or dark brown to gray-brownGo To 2
1.Upper wing: primaries, secondaries, tertials, and their coverts not uniform in color or patternGo To 6
2.Notch-length 155 mm. or shorter; primaries strongly curved ventrally; some underwing middle coverts whiteRuddy duck
2.Notch-length 180 mm. or longer; primaries only slightly curved ventrally; underwing coverts uniformly darkGo To 3
3.Outermost primary black with inner web narrowing to about 5 mm. for approximately 70 mm. from its tip; or dark brown and about half the width of adjacent primariesBlack scoter
3.Outermost primary black, brown or blue and approximately the same width as adjacent primariesGo To 4
4.Outerweb of next to outermost primary narrows abruptly 30 mm. to tip; tertials solid black or dark brown (usually with a reddish cast) and narrow light edgingOldsquaw (part)
4.Outerweb of next to outermost primary tapers gradually over length; tertials blue, black, or brownGo To 5
5. Outermost primary as long or longer than the next primary; notch-length 212 mm. or longerSurf scoter
5.Outermost primary varies from longer to shorter than next primary; often bluish: notch-length 203 mm. or shorterHarlequin duck (part)
6.Some secondaries part blue, green, or purple
Go To 7
6. Secondaries not blue, green, or purpleGo To 16
7.Some secondaries all or part blue or purple
Go To 8
7.Some secondaries part greenGo To 12
8.Blue bordered front and back by white on both the greater coverts and the trailing edge of the secondariesGo To 9
8.Blue bordered front or back (not both) with whiteGo To 10
9.Tertials straight, brown with light edging, or reddish brown grading into silver-gray; underwing white
9.Tertials curve outward, usually blue; middle and lesser coverts white or brown; underwing part darkSteller's eider
10.Greater, middle, and lesser coverts brown; tertials longer than secondaries; underwing whiteAmerican black and Mottled ducks 1
10.Greater, middle, and lesser coverts blue or bluish; tertials approximate secondaries in length; underwing not whiteGo To 11
11.Trailing edge of secondaries white; underwing barredWood duck
11.Trailing edge of secondaries dark; underwing darkHarlequin duck (part)
12.Middle and lesser coverts blueGo To 13
12.Middle and lesser coverts not blueGo To 14
13.Primary shafts white; notch-length 210 mm. or longerNorthern shoveler (part)
13.Primary shafts brown; notch-length 205 mm. or shorterBlue-winged & cinnamon teals
14.Greater coverts banded with cinnamon; trailing edge of secondaries banded with white; outerweb of most distal tertial longitudinally striped with black or brownGo To 15
14.Greater coverts banded with black; trailing edge of secondaries banded or unbanded; outer web of most distal tertial white or whitishAmerican wigeon (part)
15.Notch-length 200 mm. or lessGreen-winged teal
15.Notch-length 240 mm. or moreNorthern pintail (part)
16.Three or more secondaries white or whitishGo To 17
16.Secondaries (exclusive of trailing edge or flecking) not whiteGo To 27
17.Some greater coverts black; none whiteGo To 18
17.Some greater coverts are white or partly soGo To 20
18.White confined to 3 or 4 secondaries next to tertials; others cinnamon or light edged with internal patterns; underwing whiteGadwall
18.Most secondaries white, banded with black near their tips; upperwing covert black or dark brown often flecked with white; underwing partly darkGo To 19
19.White of upperwing confined to secondariesLesser scaup
19.White of upperwing extends to primariesGreater scaup
20.All upperwing secondary coverts so heavily vermiculated with white as to appear whiteCanvasback (part)
20.Some upperwing secondary coverts not white, none vermiculatedGo To 21
21.White on secondaries does not reach the shafts; tertials black with central white stripesHooded merganser
21.White extends to the shaft or beyond; tertials black, dark gray, or white with black marginsGo to 22
22.Tertials black; notch-length 180 mm. or lessBufflehead
22.Tertials variable; notch-length 190 mm. or moreGo To 23
23.Underwing coverts all solid black, gray, or brownGo To 24
23.Underwing coverts mostly white; upperwing middle and lesser coverts white, black, or grayGo To 26
24.Middle, lesser, and marginal coverts are a uniform black or brown; notch-length 245 mm. or longerWhite-winged scoter
24.Middle and lesser coverts white, or black washed with white or gray; notch-length 240 mm. or lessGo To 25
25.Black bases extend over more than half of each greater secondary covertBarrow's goldeneye
25.Black bases extend over less than half of each greater secondary covertCommon goldeneye
26.Black bases of secondaries are exposed on a normally spread wingRed-breasted merganser
26.Black bases of secondaries are covered on a normally spread wingCommon merganser
27.Secondaries gray, usually with white tips and a dark sub-terminal bandGo To 28
27.Secondaries brown or black, without white trailing edgeGo To 29
28.All upperwing coverts dark brown to black; tertials dark brown to black with faint greenish sheenRing-necked duck
28.All upperwing coverts gray to gray-brown, may vary from plain to heavily flecked and/or vermiculated with white; tertials vary from gray-brown with or without flecking to white well vermiculated with dark grayRedhead or canvasback (part)2
29.Secondaries black or mostly soGo To 30
29.Secondaries brown or brownishGo To 34
30.Tertials white or mostly soCommon eider (part)
30.Tertials black, olive, or mostly brownGo To 31
31.Tertials black
Go to 32
31.Tertials olive or mostly brownGo To 33
32.Tertials sharply curved; middle and lesser coverts black, black and white, or whiteKing eider (part)
32.Tertials straight; upper wing black with most coverts washed with dark cinnamon; underwing entirely blackFulvous whistling duck
33.Tertials olive; bases of primaries and secondaries white; underwing blackBlack-bellied whistling duck
33.Tertials mostly brown; outer web of most distal white; pale barring on underwingAmerican wigeon (part)
34.Primary shafts white; underwing whiteNorthern shoveler (part)
34.Primary shafts brown; underwing dark and/or heavily barredGo To 35
35.Trailing edge of secondaries white; greater coverts light edgedGo to 36
35.Trailing edge of secondaries washed with buffGo To 38
36.Tertials brown, longitudinally striped, and pale edgedNorthern pintail (part)
36. Tertials brown, edges washed with cinnamonGo To 37
37.Tertials sharply curvedKing eider (part)
37.Tertials slightly curvedCommon eider (part)
38. Middle and lesser coverts dark brown with some well-defined buff edgingCommon eider (part)
38. Middle and lesser coverts dark brown well washed with pale buffOldsquaw (part)

1Mottled ducks occur only in southern Florida and the Gulf coast west to include Texas. American black ducks are rare in this area.
2 The specula of all redheads are recognizably lighter gray than those of adult female and both sexes of immature canvasbacks.

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