Species, age and sex identification of ducks using wing plumage pages 72 - 144

              Species Identification
I The black bases of most greater secondary coverts
on Barrow's goldeneyes extend over more than half
i of each feather and are visible on a normally spread
wing. On common goldeneyes, these black bases
cover less than half of each feather and are normally
hidden (Figure 79). Usually the outer vanes of less
than 7 secondaries are white on Barrow's
goldeneyes, but on common goldeneyes outer vanes
of 7 or more secondaries are white.
Age and Sex Identification
Adult males of each species are sufficiently dis-tinctive
to be easily identified. Adult females of
both species have a broad black band across the tips
of the greater secondary coverts. Immatures of both
species have greater secondary coverts with white or
variably spotted tips (not banded) that are often
slightly frayed. The sexes of immatures appear simi-lar,
but 95% may be identified on the basis ofwing
length.
Wing I
Immature I ~ d u ~ t
Entirely white White, with or without traces of black at their tips which are White with a wide black
often slightly frayed band across their tips
Greater tertial I Black, tips rounded and not Black, somewhat pointed, often both frayed and faded at tips Black; tips rounded and coverts 1 frayed 1 often showing traces of pray 1
Tertials
- . -. .. - . -- .- .- -- --
COMMON BARROW'S
IC-ADULT
MALE
IMMATLIRE MALE
INllVlATURE FEMALE
ADUCI' FEMALE
Figure 79. Greater secondary coverts of common and Barrow's goldeneyes
76
1 Wing Male Chancier 1 I Immature d +m&? Adult
band across tips; black
1 bases show as a narrow band
I secondary sometimes with black
coverts 1 tipping; bares form a broad 1 black band
- --
Notch-length 1 97% w 222 mm. 1 96% > 217 mm. 94% < 217 mm. 1 96%  1 65 mrn %8> >9 1 6 xm. - 97$b i160m-rn- --i 9 9%< 165 mm.
Marginal 1 Black with white fringe 1 Dark brown to black
coverts I
1 Tertials I Solid black and pointed 1
Sex Determination of Adults
Adult males have shiny black, unfrayed tertials
with longitudinal white stripes and light gray mid-dle
and lesser coverts. Adult females have shiny
black tertials with longitudinal white stripes, which,
while tapering (as in males), are slightly shorter and
blunter. The middle coverts of females are a black-ish
brown to grayish.
Age Determination
Immatures are similar in gross aspect to adult
females, but immature tertials are straight and
frayed at the tip and often appear brown. The mid-dle
and greater coverts usually are frayed and
brown, particularly over the tertials. These feathers
are smooth and unfrayed on adults.
A few immatures can be identified as males by
the presence of one or more light gray middle or
lesser coverts emerging among the darker feathers;
however, the sex of most immatures cannot be
determined.
11 wing I Male Character I Adult 1 Immature
1 Female
1 Immature 1 Adult
1 Tertial coverts Black and pointed 1 Dark brown and pointed; often frayed and faded 1 Black and pointed I - . - . - -.
Gfeater Broadly banded at tips with Variabl banded at tips with white which is often poorty
covwts sharply defined white dfIfi-n.s iand frequently wiM dark edging
tips often ragged and frayed
over secondaries brown but slightly paler
distallv
SEPARATIONO F RED-BREASTEDA ND
COMMONM ERGANSERS
The white greater secondary coverts on common Sex of approximately 97% of immature common
mergansers hide the black bases of the secondaries mergansers can be determined from wing notch-and
adult males normally show only one black bar, length measurements provided primary growth is
i.e., the bases of the greater secondary coverts. complete. In addition, most immature males have
Females and immatures of both sexes normally several more distal middle and lesser coverts that are
show none. Adult females and a few immatures a lighter shade of gray than the surrounding coverts.
have a different type of bar due to black tips on the This light patch of feathers is subject to consider-greater
coverts rather than exposed bases of the able variation in shade, but it does not occur on
secondaries. On red-breasted mergansers of all ages immature female wings.
and sexes, the white greater secondary coverts do Red-breasted mergansers do not show the same
not cover the black bases of the secondaries. Thus, degree of difference in wing length between sexes as
the wings of adult males show two black bars and common mergansers. Among immatures, the
the wings of adult females and immatures of both degree of overlap is great enough to make measure-sexes
show one black bar anterior to the speculum. ments of little use for determining sex. Also,
On red-breasted mergansers, the most distal tertial because immature males do not have pale coverts
is partially white on adult females and both sexes of similar to those of common mergansers, their sex
immatures. On common mergansers of the same cannot be determined with accuracy.
age and sex groups, this feather is dark gray.
RED-BREASTEDM ERGANSER
I Greater tertial Most are white with All are dark gray-black and taper to tips which are usually All are shiny black with coverts 1 smoothlv rounded LDS 1 fraved 1 smoothlv rounded IDS 1 Middle and Do not completely cover dark bases of greater coverts on normally spread wing
lesser
secondary
coverts Entirely white I Dark gray with females slightly darker than males 1 Very dark gray to black -
Two Most Distal Primaries:
(a) 10th primary shorter than 9th primary and (b) 9th primary is the longest, outerweb of this
either black and attenuated, or gray-black feather narrows near tip ................ Oldsquaw
and tapering but much narrower than 9th (c) 10th primary longest, all primaries are uni-primary
................................. Back scoter formly tapering .............................S urf scoter
(a) (b)
Black Scoter Oldsquaw
Figure 103. Variation in the outer rwo primaries among three species
(4
Surf Scoter
The underwing of all oldsquaws is a uniform Tertial coverts, middle coverts, and most lesser
patterned dark brown to black. On adult males, the coverts are dark brown to black heavily washed with
innermost tertials are solid black, and the outer tan. The upper wing of both sexes of immatures is
tertials and adjacent secondaries show traces of rust. uniformly dark brown, often with a faint trace of
The remainder of the wing is an unpatterned black. rust on the secondaries and tertials. Immatures can
On adult females, the tertials and adjacent secon- be recognized by the frayed and faded tips of their
daries are a dark ruhs brown that has a tan edging. tertials and tertial coverts.
Wing L ~ a l e 1 Female
Character I 1 Immature 1 Immature 1 Adult
I
Tertials Acutely pointed, black, most arkg gray-brown; usually show trace of rust Dark brown with trace of
-. . . - - . - - - - . . . .
rust; usually tan edging ] - - / Greater tertial 1 Entirely black 1 Dark brown, usually frayed and faded at tips Dark brown; tips washed
coverts 1 with tan --
Dark brown; frayed and faded at tips Dark brown, tips washed
I secondary with tan
coverts - -1 The underwing of all ages and sexes is completely often with poorly defined white areas near their
dark and unpatterned. Adult male wings are easily tips. Wings of immatures of both sexes are a deep
identified by the extremely attenuated outermost brown. Tertials are relatively short with frayed tips.
primary and the completely black upperwing. Greater coverts are frayed and faded at their tips.
Adult female wings are dark brown. Their tertials Immature wings are about the same color as those
normally have bluntly rounded unfrayed tips. of adult females. Although male wings are slightly
Greater coverts are broadly rounded and unfrayed, larger than those of females, there is much overlap.
I WChinagra cter F- 1 Female
/ Immature 1 Immature ( Adult
Not attenuated but noticeably narrower and shorter than the next primary
than adja-cent- prima ry - . -- . -- -- . -- - . - -. . - . - 1 Shiny black and acutely Dark brown and sharply pointed; often faded at their tips Very dark brown and bluntly 1
pointed; approximately 30 1 pointed; approximately 20
mm. longer than most mm. longer than most 1
secondaries 1 secondaries !
Tertial coverts Shiny black with rounded Dark brown; n z w slightly toward their tips which are
/ / I p S - g y frayed and faded , ,
Dark brown; with rounded
.. .
tips
- -.
black with rounded Dark brown; greater coverts often slightly faded near tips; Dark brown; may be faded at
I appear
their tips
coverts I I
All surf scoter wings are dark and unpatterned on greater coverts over both secondaries and tertials.
both upper and under surfaces. Only adult males On immature birds, tertials are pointed and usually
are black. Wings of all other sex-age categories are frayed and faded at their tips, and greater coverts
dark brown. Among these, adult females-can be over both secondaries and tertials are quite narrow
identified by their broadly rounded tertials and and have frayed and faded tips.
---------
T i - Character 7Imm ature Immature I - - I Adult
Tertials Shiny black and bluntly Dark brown and pointed; may be faded at their tips
pointed; approximately 20
rnrn. longer than most
secondaries
Very dark blackish brown;
tips bluntly pointed; usually
less than 20 rnrn. longer
than most secondaries
/ Greater, ( Entirely black; appear ' Dark brown; most greater coverts are faded at their tips; they Very dark blackish brown;
middle, and smooth 1 often appear rough some are slightly faded at
lesser coverts their tips; all appear smooth
Age Determination
Immatures of both sexes are generally a lighter
brown than adult females, but do intergrade some-what.
On immatures, the tertials and tertial coverts
usually have some faded fraying at their tips. Similar
light-colored fraying is often present among the
scapulars. The greater coverts often have much less
white at their tips than those of adults and some-times
they are entirely brown.
Sex Determination of Adults
Adult males can be readily identified by the black
of all uppenving feathers except for the secondaries
and the outer half of their greater coverts which are
white. The sharply defined black bases of the sec-ondary
coverts create a saw-toothed appearance.
There is no evidence of fading or fraying on either
tertials or tertial coverts. Adult females are similar
except that the uppenving is a very dark brown
rather than black. It may be necessary to tilt the
wings and view them closely to see that they are not
black. Approximately 90% of adult females have a
notch-length of less than 274 mm. and approxi-mately
90% of adult males are longer.
Female 1 Character (lmmxre 1 Immature Adult
, .- - -
I Tertials 1 ! a r b tips are blunt
-I and rounde.d . . . .. -. . . -. - - This species occurs only casually in the more is probably reliable, it should be used with caution.
northern states of the Atlantic Flyway. Although At present, a serious problem with king eiders is the
common in Alaska, few are shot. Only a few wings lack of a reliable method for separating females and
from known-aged birds were available for study. immatures of this species from the same age and sex
Therefore, although the information presented here classes of common eiders.
Greater tertial Broadly rounded and black Usually narrowly edged with pale brown; often frayed at tips Broadly rounded, very dark
coverts 1 brown. broad pale brown 1 edging
Wing
Character
Entirely white except for the Similar to adult female but edging is darker and somewhat Broadly rounded, very dark
leading edge of the wing narrower brown, broad pale brown
e d ~ i n ~
Male Female
Adun 1 Immature I Immature 1 Adult
1 Wing Character 1 Adult 1 Immature LT ert-ial coverts L8madly rounded at tips - . - 1S omewhat squared at tiKappearing trap.ez oidal
. I Tertials 1 Broad-tipped, curved and drooping I Straight, often somewhat frayed at their tips
~kG&i'S--~untied and smoo&-edged . S-lig h-tly tra p-e z-o ida.l,. o- ften- roug-h -ende . d.-
. . . . - . .
1 Wino- Character 1 Adult I Immature 1
/ Greater coverts
I 1 Broadly rounded and with a trace of fadii at their tips [ Narrow to pointed tips that have a trace of fading 1
. . . . .. . .. . .. . . . . - . - . -.. . - - - . . . . . .. - I
Broadly rounded; often a faint trace of fading that their rounded to pointed, often slightly faded at their
[ ~esserc overts ( Broadly rounded with very lie fading at the tips . - . -. - - -. 1 Narrow toward their tips which are often faded. i . - - .- .- - . . . . . . .. . .
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 (a). Upper wing: primaries, secondaries, tertials, and their coverts: all an unpatterned
black or dark brown to gay-brown ................................................................................................... 2
1 (b). Upper wing: primaries, secondaries, tertials, and their coverts not uniform in
color or pattern. ............................................................................................................................... 6
2(a). Notch-length 155 mm. or shorter; primaries strongly curved ventrally; some
underwing middle coverts white ...................................................................................... Ruddy duck
2(b). Notch-length 180 mm, or longer; primaries only slightly curved ventrally;
undenving coverts uniformly dark .................................................................................................... 3
3(a). Outermost primary black with inner web narrowing to about 5 mrn. for
approximately 70 mm. from its tip; or dark brown and about half the width
of adjacent primaries ........................................................................................................ Black scoter
3(b). Outermost primary black, brown or blue and approximately the same width as
adjacent primaries ............................................................................................................................. 4
4(a). Outenveb 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 edging ........ Oldsquaw(part)
4(b). Outenveb of next to outermost primary tapers gradually over length; tertials blue,
black, or brown ................................................................................................................................ 5
5(a). Outermost primary as long or longer than the next primary; notch-length
21 2 mm. or longer ............................................................................................................. Surf scoter
5(b). Outermost primary varies from longer to shorter than next primary; often
bluish; notch-length 203 mm. or shorter ......................................................... Harlequin duck (part)
6(a). Some secondaries part blue, green, or purple .................................................................................... 7
6(b). Secondaries not blue, green, or purple ............................................................................................ 16
7(a). Some secondaries all or part blue or purple ....................................................................................... 8
7(b). Some secondaries part green ........................................................................................................... 12
8(a). Blue bordered front and back by white on both the greater coverts and the
trailing edge of the secondaries ......................................................................................................... 9
8(b). Blue bordered front or back (not both) with white ......................................................................... 10
9(a). Tertials straight, brown with light edging, or reddish brown grading into
silver-gray; underwing white ................................................................................................... Mallard
9(b). Tertials curve outward, usually blue; middle and lesser coverts white or brown;
underwing part dark ....................................................................................................... Steller's eider
lO(a). Greater, middle, and lesser coverts brown; tertials longer than secondaries;
underwing white ...................................................................................... A. black & mottled ducks1
10(b). Greater, middle, and lesser coverts blue or bluish; tertials approximate
secondaries in length; underwing not white ................................................................................. 1 1
1 1 (a). Trailing edge of secondaries white; underwing barred ....................................................... Wood duck
1 1 (b). Trailing edge of secondaries dark; underwing dark ........................................... Harlequin duck (part)
12(a). Middle and lesser coverts blue ......................................................................................................... 13
12(b). Middle and lesser coverts not blue .................................................................................................. 14
13(a). Primary shafts white; notch-length 21 0 mm. or longer ........................................... 1 . s hoveler (part)
13(b). Primary shafts brown; norch-length 205 mm. or shorter ...................B. lue-winged & cinnamon teals
14(a). Greater coverts banded with cinnamon; trailing edge of secondaries banded with
white; outerweb of most distal tertial longitudinally striped with black or brown ........................... 15
14(b). Greater coverts banded with black; trailing edge of secondaries banded or
unbanded; outer web of most distal tertial white or whitish ........................................ A.wigeon(part)
15(a). Notch-length 200 mm. or less ............................................................................ Green-winged teal
15(b). Notch-length 240 mm. or more ............................................................................... N. pintail (part)
16(a). Three or more secondaries white or whitish .................................................................................... 17
16(b). Secondaries (exclusive of trailing edge or flecking) not white .......................................................... 27
17(a). Some greater coverts black; none white ........................................................................................... 18
17(b). Some greater coverts are white or partly so. ..................................................................................... 20
18(a). White confined to 3 or 4 secondaries next to tertials; others cinnamon or
.............................................................. light edged with internal patterns; underwing white Gadwdl
18(b). Most secondaries white, banded with black near their tips; upperwing covert
black or dark brown often flecked with white; underwing partly dark ............................................ 19
19(a). White of upperwing confined to secondaries ................................................................... Lesser scaup
19(b). White of upperwing extends to primaries ..................................................................... G e t sc aup
2O(a). All upperwing secondary coverts so heavily vermiculated with white as
2O(b). Some upperwing secondary coverts not white, none vermiculated .................................................. 21
21 (a). White on secondaries does not reach the shafts; tertials black with
21 (b). White extends to the shaft or beyond; tertials black, dark gray, or white
with black margins .......................................................................................................................... 22
22.(a) Tertials black; notch-length 180 mm. or less ....................................................................... Bufflehead
22(b). Tertials variable; notch-length 190 mm. or more ............................................................................ 23
23(a). Underwing coverts all solid black, gray, or brown ........................................................................... 24
23(b). Underwing coverts mostly white; upperwing middle and lesser coverts
white, black, or gray ........................................................................................................................ 26
24(a). Middle, lesser, and marginal coverts are a uniform black or brown;
notch-length 245 mm. or longer. ....................................................................... i t - w i n e d scoter
24(b). Middle and lesser coverts white, or black washed with white or gray;
notch-length 240 mm. or less ......................................................................................................... 25
25 (a). Black bases extend over more than half of each greater secondary covert ............... Barrow's goldeneye
25 (b). Black bases extend over less than half of each greater secondary covert ............... Common goldeneye
26(a). Black bases of secondaries are exposed on a normally spread wing ................. Red-breasted merganser
26(b). Black bases of secondaries are covered on a normally spread wing ...................... Common merganser
27(a). Secondaries gray, usually with white tips and a dark sub-terminal band .......................................... 28
27(b). Secondaries brown or black, without white trailing edge ................................................................ 29
28(a). All upperwing coverts dark brown to black; tertials dark brown to black with
faint greenish sheen ...............................................................................................R. ing-necked duck
28(b). 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 gray .............................. Redhead or canvasback (part)2
29(a). Secondaries black or mostly so ........................................................................................................ 30 29(b). Secondaries brown or brownish .....................................................................................................3. 4
30(a). Tertials white or mostly so ................................................................................. Common eider (part)
30(b). Tertials black, olive, or mostly brown ..............................................................................................3 1
3 1 (a). Tertials black. ................................................................................................................................. 32
3 1 (b). Tertials olive or mostly brown ......................................................................................................... 33
..........................................................................................
32(a). Tertials sharply curved; middle and lesser coverts black,
black and white, or white K g ei der (part)
32(b). Tertials straight; upper wing black with most coverts washed with
dark cinnamon; underwing entirely black ....................................................... Fuvous whistling duck ....................................................................................
33(a). Tertials olive; bases of primaries and secondaries white;
underwing black Black-bellied whistling duck
33(b). Tertials mostly brown; outer web of most distal white; pale barring
on underwing ..........................................................................................................A. . wigeon (part)
34(a). Primary shafts white; underwing white ................................................................... N. shoveler (part)
34(b). Primary shafts brown; underwing dark and/or heavily barred ......................................................... 35
35(a). Trailing edge of secondaries white; greater coverts light edged ........................................................ 36
35(b). Trailing edge of secondaries washed with buff ................................................................................. 38
36(a). Tertials brown, longitudinally striped, and pale edged ............................................... N. pintail (part)
36(b). Tertials brown, edges washed with cinnamon ................................................................................. 37
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