S DEPARTMENT OF THE INTERIOR S GEOLOGICAL SURVEY ATIONAL WETLANDS RESEARCH CENTER 30 CAJUNDOME BLVD 9FAYETTE LA 70506-3152 BY Samuel M. Carney Washingon, D.C. 1992

U.S. Department of the Interior U.S. Fish and Wildlife Service rocedures have been developed over the past 30 earsf for I 1 Pmanaging the take of waterfowl by hunters. Wings of ducks contributed voluntarily to the U.S. Fish and Wildlife Service by hunters are examined each year by experts. This procedure involves the determination of species, sex, and age of ducks through an examination of these detached wings. Many persons skilled at examining wings of ducks have retired in recent years. We became concerned that these skills might be lost to Jitturegenerations ij'not properly documented. Documenting such skills is dificult. Subtle dzferences in feather color andfeather texture are used to I distinguish young ducks from adult ducks and males from females. Printed words and pictures have their limitations, but we hope this publication captures the technique and preserves it.

/' Director U.S. Fish and Wildlife Service Introduction ...... 1 Common goldeneye ...... 75 Feather groups of the duck wing ...... 2 Barrow's goldeneye ...... -81 Mallard ...... 5 Separation of bufflehead and American black duck ...... 1O hooded merganser ...... 86 Mottled duck ...... 13 Bufflehead ...... 87 Gadwall ...... 16 Hooded merganser ...... 92 American wigeon ...... 19 Separation of red-breasted and Green-winged teal ...... 24 common mergansers ...... 96 Blue-winged and cinnamon teals ...... 28 Red-breasted merganser ...... 96 Northern shoveler ...... 3 1 Common merganser ...... 100 Northern pintail ...... 34 Separation of oldsquaw. black scoter. Wood duck ...... 39 and surf scoter ...... 05 Harlequin duck ...... 42 Oldsquaw ...... 106 Steller's eider ...... 45 Black scoter ...... 10 Separation of redhead and canvasback ...... 48 Surf scoter ...... 114 Redhead ...... 49 White-winged scoter ...... 118 Canvasback...... 54 Common eider ...... 122 Separation of greater and lesser scaups ...... 59 King eider ...... 127 Greater scaup ...... 59 Ruddy duck ...... 132 Lesser scaup ...... 6 5 Fulvous whistling duck ...... 135 Ring-necked duck ...... 70 Black-bellied whistling duck ...... 138 Separation of common and Appendix: Key to duck species ...... 141 Barrow's goldeneyes ...... 75 his publication contains procedures used by the texture and feather quality with high levels of profi- TU.S. Fish and Wildlife Service to determine ciency. Levels of skill will decline if techniques are the species, sex and age composition of the harvest not practiced with regularity. of North American ducks using detached wings Terminology related to age must be clarified. An contributed by hunters. Original studies of the use immature wing possesses one or more characteristics of duck wings for this purpose began in 1958 and known to be associated with ducks hatched in the were led by the author and A.D. Geis. Others con- most recent nesting season. Since the term imma- tributing to these studies include R.L. Croft, E.M. ture often refers to maturing processes not related to Martin, A.N. Novara, L.D. Schroeder, M.G. Smart, plumage, juvenalmight have been more appropri- and M.F. Sorensen. Major suppliers of known-age ate. Nevertheless, after 30 years of use in this con- specimens include: W. Anderson, R.S. Billard, text, introducing another age designation would A.J.Erskine, D. Hall, A.S. Hawkins, C. Hoffpauir, serve no purpose. All wings not possessing charac- L.R. Jahn, R. L. Jessen, F.B. Lee, J.J. Lynch, R.K. teristics associated with the most recent hatch are Martinson, D.I? Olson, R.I? Osbolt, C. Ritcey, classified as adult except those of male R.N. Smith, H.E. Spencer, V.D. Stotts, and J. eiders which are identified as being from sub-adults. Takekawa. R.I. Smith edited the text, A.J. Godin To determine the species, age, and sex of ducks prepared Figure 2, Larry Ketchum Photography from detached wings, a worker must be familiar took the pictures, and R.E. Cummins typed the with the various feather groups (Figure 1). The first manuscript. step is to determine the species represented. A key The Waterfowl Parts Survey became the means by to species is included as an appendix to this publica- which large samples of duck wings were obtained. tion. Usually, slight differences in feather shape, This survey became national in scope in 1961. color, pattern, wear, or replacement are sufficient Collection of goose tails was added to the survey in during the fall and winter to separate immatures 1962. Packages of envelopes are mailed to selected from adults. Age determination is a step-by-step hunters who return wings from shot ducks and tail search for one or more traces of immature plumage. feathers from shot geese by mail to collection points Wings on which no traces of immaturity can be throughout the United States where they are exam- found, or in some cases those that have positive ined to determine species, sex, and age. adult characters, are considered to be from adults. For readers who are interested in more detailed During their first fall and winter immatures of information on the development and testing of many of the more common species of ducks molt procedures described in the following pages, copies certain wing-feather groups located near the body of a more technical report, which was prepared by and replace them with adult-type feathers. Those the author, are available by writing to Waterfowl feathers that are replaced include the tertials, greater Harvest Surveys, U.S. Fish and Wildlife Service, tertial coverts, post humerals, and scapulars. 10800 Laurel-Bowie Road, Laurel, Maryland Scapulars are of limited use in classifying wings 20708-3600. That report, titled Observations on because most hunters do not include scapulars on Sexing andAging Ducks Using Wings, makes several the wings they remove. Tertials, as defined here, are points that must be understood by anyone who actually the more proximal secondaries, which are plans serious use of these techniques. The proce- generally different in size, shape, and color from dures presented here vary among species in the their more distal counterparts. These feathers are degree to which they accurately identify the age and often sexually dimorphic and usually molt with sex of duck wings. Accuracy varies according to adjacent body feathers. Post humerals are feathers skills of the observer. Some individuals become attached to the humerus. They lie between the highly skilled after examining large numbers of tertials and scapulars. They usually molt with adja- duck wings, while other individuals never develop cent body feathers. Greater coverts are the first row the ability to detect subtle differences in feather continued on page 4 FEATHER GROUPSOF THE DUCKWING

REMIGES: (Flight feathers) Alula: The feathered "thumb" of the bird wing Primaries: Flight feathers attached to the hand (manus) Secondaries: Flight feathers attached to the forearm (ulna) Tertials: Incorrect (morphologically) but used here to designate the more prox- imal secondaries which are generally different in size, shape, and color from their more distal counterparts, are often sexually dimorphic, and usually molt with adjacent body feathers. Post humerals: Feathers attached to the humerus. They lie between the tertials and scapulars, usually molting with adjacent body feathers. Scapulars: Feathers of the humeral (upper arm) feather tract. These lie on either side of the back and may partially cover a folded wing. They usually molt with adjacent body feathers. (Not shown) Axillars: Elongate feathers growing in the "armpit" region and closing the space between the spread wing and the body WING COVERTS: (Cover flight feathers) Greater coverts: The first row of feathers overlying the flight feathers, identified by the particular feathers they cover as primary, secondary, or tertial coverts. Tertial coverts: Those greater coverts that overlie the tertials. Designated separately here because they are sexually dimorphic in adults of several species and usually molt with the adjacent body feathers. Middle coverts: The next row of coverts. Lesser coverts: The next several rows of coverts. Marginal coverts: An indefinite number of rows anterior to the lesser coverts

2 PRIMARIES

Figure 1. Feather groups of a typical dabbling duck wing of feathers overlying the flight feathers, identified by both fresh wings and wings with varying degrees of the particular feathers they cover as primary, sec- stiffness, as they are commonly received through the ondary, or tertial coverts. Greater tertial coverts are Waterfowl Parts Survey. To ensure uniformity all those greater coverts that overlie the tertials. They measurements are made using a standardized proce- are designated separately because they are sexually dure and measuring board (Figure 2). Measure- dimorphic in adults of several species and often ments are referred to as wing notch-length. molt with the adjacent body feathers. The degree to Tables have an advantage over keys in that the which these feathers are replaced is quite variable, color, shape, or texture of a particular group of I even among closely related species. Southern nest- feathers can be compared on one page across the ing duck species may initiate upperwing molts in four age and sex categories. Unlike keys, tables do the fall rather than in the spring. Fall wing molting not lead one directly to the answer. Despite this occurs among wood ducks, mottled ducks, and limitation, most people prefer tables to keys. whistling ducks. Such molting reduces the accuracy Therefore, tables are used in this publication to of immature wing identification in the fall and present information on individual species. Wing characteristics are not always listed in the same Male wings on most North American ducks are sequence for each species. They are listed in the slightly larger than those of females. For a few sequence in which they can be most efficiently used. species, this difference is large enough to permit A brief narrative, which identifies the most separation of the sexes using wing measurements. frequently used wing characters in a table, accompa- The procedure for measuring duck wings applies to nies most tables.

Place the heel of one hand over the end of measuring board and grasp wing in the area of the radius and ulna. Pull until wooden block seats tightly into the notch at the bend of the wing. Flatten the leading edge of the wing and note the length of the wing at the longest primary. Note: If primary quills are not completely grown, the measurernent is not val~d.

Figure 2. Procedure for measuring wings

4 Sex Determination ance to adult feathers. At the same time, immature The white bar anterior to the speculum extends tertial coverts may be replaced by coverts which are onto the greater tertial coverts on all female wings broader, unfrayed, and similar to adult coverts and but terminates at the proximal edge of the specu- thus differ from adjacent immature coverts, which lum on nearly all male wings. Approximately 2%-3 have not been molted. Many immature males have percent of males show some white edging on their light edging on the inner webs of the most distal tertial coverts. Adult males can be identified because primary coverts. Adult males do not show this char- the white is not continuous with that over the sec- acter. Middle coverts of immatures are narrower and ondaries. Immature males with white over the ter- more trapezoidal than those of adults. Occasionally, tial coverts are difficult to tell from immature these feathers on immature males are worn and/or females. The white bar is the easiest sex character to have light edges. This type of edging does not occur use, because of its high degree of reliability and the on the middle coverts of adult males. fact that it is rarely lost when a wing is detached. Vermiculated scapulars are found only on males. Age Determination of Females Early in the hunting season (September and Tertials that are frayed and/or faded are remnants October) many males possess barred scapulars of immature plumage and are found only on imma- which are remnants of their summer plumage. ture ducks. Tertial coverts of immatures are often Proximal underwing coverts are vermiculated or frayed, faded, and narrow, and the two most proxi- flecked on adult and most immature males. These mal often lack the white of the speculum bar. As feathers are barred on females and on a few imma- with males, greater tertial coverts of immatures may ture males. be replaced. Conspicuous light edging on the inner webs of the four most distal primary coverts is Age Determination of Males found only on immatures. Adults may have minute Immature tertials are often frayed and faded, or no edging on these coverts. ~iddlecoverts of usually narrow, and lack the pearly color of adult immatures tend to be narrow and trapezoidal, while tertials. By late November immature tertials are those of adults are broadly rounded. replaced by first winter tertials, identical in appear-

Wing Male 1 Female Character Adult 1 Immature / Immature 1 Adult Scapulars 1 Venniculated o'barred or both / Barred + -. - I I Proximal Flecked to vermiculated I Barred 1 I

Tertials Broad, pearly gray, no Small, narrow, brownish, often frayed or faded near tips. Varies from pearly gray to edging, rarely frayed or Adul type feathers may be growing in December or later brownish, often light edging; faded' May be growing in rarely frayed or faded October After mol: Similar to adul After mol: Similar to adul male female ------roiinded;.sotid gray SiigMfy ttiangukr to Woidal; often frayed or faded; Broadty rounded; brown; to brown, no edgtljs usually bmwn ~suaHywSth light brown @iQlng; sometimes no Ma) have fiie'edging or no Edging varies from edging w9 conspicuous to absent I Primary No edging Inner web of four most distal Inner web of four most distal Innerweb of four most distal coverts have llght edg~ngor no wlthout edglng to wlth llght edglng or no edging conspicuous edging edging I m.; a IFigur-e 5. Adult hniale rnallrird ~virhunecigid co\.ct-ts

Figure 6. Immature male mallard with immature tertials

Age Determination Sex Determination of Adults Because wings of the sexes are similar, it is easier Adult male tertials are more than 90 mm. long to determine the age of black ducks before attempt- from the edge of the longest tertial covert to the ing to identify their sex. Tertials small, narrow, and tertial tip, and acutely pointed with some pearly frayed andlor faded near their tips are remnants of color on the outer webs. Tertial coverts have broad immature plumage. Adult tertials are longer and edging which is pale brown. Middle and lesser wider and are not frayed or faded. Tertial coverts of coverts are broadly rounded and unfrayed. The the immature plumage tend to be narrow, some- notch-length of 94 percent of the adult male 1 what trapezoidal, and frequently frayed andlor known-age specimens was greater than 28 1 mm. faded. Those of adults are wide, broadly rounded, Adult female tertials are less than 90 mm. from j and rarely frayed or faded. During their first fall and the edge of the longest tertial covert to the tertial I winter, a substantial fraction of the immatures may tip, and they are rather bluntly pointed. Pearly color 'I I replace both their immature tertials and tertial generally does not occur on the outer webs. Tertial coverts with adult-type feathers. Thus, it is impor- coverts have broad edging which is pale brown. I tant to look closely at the middle coverts immedi- Middle and lesser coverts are broadly rounded and l ately anterior to the tertial coverts for indications of unfrayed. The notch length of 94% of adult females the trapezoidal shape, duller color, and wear that was less than 281 mm. indicate immaturity. Primary coverts of many Immature tertials less than 88 mm. from the immatures have light edging on their inner webs. longest covert to the tertial tip are from females and This type of edging does not occur on adults. longer tertials are from males.

1 Wino 1 Male 1 Female 1

I Y"Y'YY'"' I Adult I Immature I Immature I Adult I

After molt: Similar to adult After molt: Similar to adult rounded'arc; not frayed of 1 male female 1 faded I

1 Greater 1 Four most distal do not have 1 Four most distal otten (but not always) have light edging on 1 Four most distal do not have I I ure 11. Adult female black duck pnp y3qq spur a~naewwI'~1 ;arnS!j C - - 1 Because mottled ducks are southern nesters, most females, but there is considerable overlap. Birds immatures have replaced both tertials and greater with three or more non-iridescent secondaries are tertial coverts at the time hunting occurs. Careful virtually all females, but birds with only one or two scrutiny, however, will usually reveal one or more non-iridescent secondaries may be of either sex. faded coverts in this area. These are remnants of the The greater tertial coverts of females tend to more immature plumage. Sexual identification is difficult. heavy edging than those of males, but the two types Wings of males are generally longer than those of grade together.

Male I Female , Adult 1 Immature I Immature I Adult Similar to adult males; lack Similar to aduk females; I Often bluntly pointed; internal markings oflen internal markings often r mm.;lack internal

. .- 4 Broadly rounded; edging Usually similar to those of Usually similar to those of Broadly rounded with heavy varies from broad to narrow adult males; often one or adult females; sometimes tan edging more narrow and frayed or one or more narrow and faded fraved or faded

1 Notch-length I 81% > 255 mm. 1 84% > 251 mm. 1 81% < 250 mm. 1 86% < 254 mm. 1

Sex Determination of Adults Sex Determination of Immatures

Greater, middle, and some lesser coverts of adult Tertials of both sexes are short, bluntly. .pointed, males are mostly either black or cinnamon. On and ofieti frayed at their tips. They are quite similar adult females, black and cinnamon feathers are to those of adult females. In late fall, they may be much restricted to the posterior three or four rows replaced by sexually dimorphic adult-type tertials. of coverts. Tertials of adult males are long, acutely Greater tertial coverts of both sexes usually appear pointed, silver-gay without edging or tipping. part black and part gray and are tipped with cream. Those of adult females are much shorter, more They are narrower and more pointed than those of bluntly pointed, and silver-brown with cream col- adults. Greater, middle, and sbme lesser coverts of ored tips. Greater tertial coverts of adult males are immature males have some black andlor cinnamon part black and part gray, rarely with traces of white in three or more rows. Immature females usually tipping. Those of adult females are similar but usu- have little or no cinnamon color and black is ofien ally well tipped with white. Marginal coverts of restricted to two rows of coverts. Some males show adult males are without edging but have arcs of arcs of narrow vermiculation. Both sexes may show narrow vermiculation. On adult females, these pale barring, which is usually wider on females. feathers are similar to the lesser coverts and ofcen Notch-length measurements are usehl to identify have edging but may be either plain or with wide immatures by sex, as long as the shafts of the pri- internal bars or arcs. Post humerals of adult females mary feathers have hardened. In 90 percent of the usually have cream edging at their tips. Those of specimens measured, immature male notch-lengths other ages and sexes do not have this edging. were equal to or greater than 255 mm., while those of immature females were less than 255 mm.

---

------Immature Immature 1 Scapulars vorbanedorbath Barred - -. ------. I Tertials Long, acutely pointed; Small; brownish; bluntly pointed; usually Shorter; bluntly pointed; silver-gray; without edging; gray-brown with ------tips not hayed Or faded cream-colored tips which are not frayed or faded

Greater tertial Bluntly pointed; outer webs Somewhat pointed; outer webs black; inner webs brown; Broadly rounded; usually coverts black; inner webs gray, often frayed and faded at tips with white tipping; outer rarely with traces of white webs black or brown; inner 1 tipping; not frayed or faded k-7After molt: Similar to adult After molt: Similar to adult websfaded brown; not frayed or

1 Post 1 Broad, rounded, tips without 1 Narrow; pointed; tips without edaino 1 Broad rounded tips, usuallv 1 1 humerals edaing 1 1 liaht- edaina-" . I hotznath75e262-. mm...... I 80% > 255 -mm. .. ( 80#s 255mm. I 9~%c~rnm. 1

Adult males have a large white uppenving patch, with well-defined pale tan edges. Often the greater long acutely pointed tertials with black outenvebs, secondary coverts lack most of the black tipping and gray greater tertial coverts that are somewhat common to wings of other ages and sexes and their pointed and narrowly white-edged. outer webs are brownish gray to gray-white. Adult females have a sharply defined white Separation of American wigeon wings from edging on both greater and middle tertial coverts. Eurasian wigeon wings can be accomplished using Usually the sharp white edging on the middle and the following procedures: lesser coverts is sufficient to identify adult females, however, a few are so lightly colored as to resemble American wigeon immature males. A carehl check of tertials and Axillars (if present) entirely white or flecked only greater tertial coverts will serve to identify them. at their tips. Immature males usually have small, brownish Undenving middle coverts all or nearly all white. tertials and tertial coverts, but by November these Scapulars of males (if present) are heavily vermic- are often replaced with adult male-type feathers. ulated with reddish brown. The middle and lesser coverts are gray-brown and indistinctly edged with a lighter gray. Eurasian wigeon Immature females have small, brownish tertials Axillars (if present) heavily flecked with gray over and tertial coverts similar to those of immature their entire length. males. By the middle of the fall hunting season Underwing middle coverts heavily flecked with these may be replaced with adult female-type feath- gray. ers. The middle and lesser coverts are brownish Scapulars of males (if present) are heavily vermiculated with black and white.

Male 1 Female KYaeter Adult 1 1 1 Immature I Immature I ~du~t . -- Scapular~ I Vmiculated w barred or both I Barred I -- A. Underwing Coverts gray, heavily flecked with white Coverts brownish; heavily edged with white to gray ( Occasionally as in females I

Brown with light gray-brown edging; often frayed and faded Dark brown; edged with white to form a broadly narrow white edging After molt: Similar to adult I After molt: Similar to adult rounded arc male female

GREEN-WINGEDTEAL

If the scapulars are attached, the presence of one frayed. Adult female-type tertials have cream col- or more vermiculated feathers indicates that the ored edging. Adult male-type tertials are long, with- wing is from a male. If none of the scapulars are out edging, or with narrow edging. The presence of vermiculated, the wing could be that of either a adult-type tertials is not by itself an indication of male or female. age. Many geen-winged teal molt tertials during The stripe on the most distal tertial is the most the hunting season. For some of these, it is possible useful indicator of sex. On the wings of males, this to split incoming pin feathers to see whether the stripe is black and sharply delineated from the basic new feather is male or female in character. For feather color. On the wings of females, this stripe is wings with molted tertials, determination of sex is black to brown, but grades into the basic feather not possible. color. The sex of approximately half of the imma- Tertial coverts that are long and narrow, showing ture birds can be identified by measurements. fine, light edging, and a frayed fringe are remnants Wings 183 mm. or longer are from males and of immature plumage and positively identify the wings shorter than 175 mm. are from females, but wing as being immature. The tertial stripe may be sex cannot be determined from measurements used to separate the sexes. Adult female-type tertial between 176 mm. and 182 mm. A sample of wings coverts are broadly rounded with wide edging that from Adak Island, Alaska, green-winged teal (con- is cream or brown. Adult male-type tertial coverts sidered a different subspecies) averaged approxi- are a uniform gray, sometimes with a narrow bu@ mately 5 percent longer than wings collected in the edging, and tapering to a blunt point. Adult-type lower 48 states. The number of iridescent secon- tertial coverts are not a reliable indicator of age. daries differs between sexes. Wings having fewer Middle coverts of adult males are smooth and than four secondaries with completely iridescent without edging. Middle coverts of immatures are green outer webs are usually from females and rough and may show gray-appearing wear at their wings with five or more such secondaries are usually edges. Immatures may also possess light edging from males. Sex cannot be determined in this man- which is more pronounced on females, but may also ner from wings with four or four and a half irides- be present on males. Broad, rounded middle coverts cent secondaries. with wide edging are found only on adult females. Immature tertials are small, narrow, and rather Traces of immature plumage usually remain most delicate. The tips of these feathers are often badly obvious immediately anterior to the tertial coverts.

Wing Male 1 Female Character Adult I Immature 1 Immature I Adult

Tertials Uniform gray; tapering to a Small; narrow; rather delicate tips are often badly frayed; Buff edging including usually buff edging rounded tips; unfrayed; longitudinal stripe often poorly defined along inner edge; may be brown or black; stripe sometimes well defined; may be molting I 1 1 ( male 1 female I

1 Middle and Broadly rounded; no edging; Gray with wear around edges; appear ragged; somewhat Broadly rounded; usually lesser coverts gray that matches tertial narrow and trapezoidal; late in year contrast to a variable with wide light edgjng but coverts deoree with new freolaced) oreater coverts sometimes no eda~na

Sex Determination adult males but are usually still growing in The speculum of males is a bright iridescent December. Adult and replaced tertial coverts of green and that of females is a dull non-iridescent immatures are similar, i.e. a dark brownish black green. Rarely, a female may show a trace of irides- without edging but usually showing a blue wash. cence. The greater secondary coverts of males Immature-type tertial coverts are brown, usually appear entirely white on their outer webs while with pronounced edging and tan and usually not those of females are heavily dark spotted and fre- washed with blue. quently appear more dark than light. A few males may show some spots in the greater coverts. Age Determination of Females Tertials of adults are much more bluntly pointed Age Determination of Males than are the immature tertials. In addition, imma- Tertials of adults are greenish black, rarely frayed, ture tertials frequently become somewhat frayed at andyery long and pointed. They are trimmed with their tips. Tertial coverts of adults are usually a very narrow tan edging. Tertials of the immature straight sided to a rounded tip, whereas those of plumage have wide edging which is tan and they are immature birds usually narrow slightly to a rounded much shorter and more bluntly pointed than those tip that often shows traces of fading. Well propor- of adults. They are brownish and often somewhat tioned white inverted "V's" generally indicate frayed and faded at the tips. Adult-type tertials adults. occur on immatures and are similar to those of

-- --

--- , Immature I Adult

Greater coverts

Tertial Broadly rounded; dark coverts brown washed with blue; brown usually with usually without edging; not pronounced light brown frayed or faded I female

The presence of white primary shafts separates immatures are greenish black and much longer. The shovelers from all other North American ducks. All tertial covcrts of the immature male are brownish birds having specula that are more than half gray or black and often show a frayed fringe. Adult tertial dull non-iridescent green are females. All males and coverts are blackish, often washed with blue. Both a few adult females have iridescent green on more immature tertids and immature tertial coverts are than half of their secondaries. usually present during October. Most females show cream edging on the lesser Immature males generally have small dusky spots and middle coverts. This often covers all these on their greater coverts, while adults do not. feathers, particularly on adult females. Immature The immature tertials of females are similar to males may show a few cream colored edges on those of immature males. The tertials of adult feathers near the alula. females are wider, not frayed, and more heavily The tertials of immature males are brownish and washed with white at the tips. much frayed, while those of adults and first winter

Male I Female EFacIer Adul, 1 I Immature 1 Immature I Adult

Smoothly rounded; dark Brown; often much frayed; with trace of light edging Brown; white edging forms brown to shiny black; smoothly rounded arc unfrayed After molt: Similar to adult After molt: Similar to adult male female

White; dark bases normally White; often with small dark White; about 114 - 112 inch of dark base normally shows covered by middle coverts spots at tip; about 114 - 112 lnch of dark base normally shows

31 '-

'Ad

Sex Determination one wing in 20 shows faint light edging, but the The speculum is at least partly iridesceRgreen general aspect of these is such that they can readily (rarely purple) on males and a dull non-iridescent be identified as adults. F bronze or rarely non-iridescent green on females. The tertial coverts of the immature plumage have The underwings of most males are flecked to ver- conspicuous edging which is a light yellowish miculated; those of a few males and all females are brown. Birds with such wings are immature males. barred. Male adult and first winter tertials are long Tertial coverts of the adult-type lack edging and are and gray and the innermost has a wide marginal found on both adult and immature wings. Tertials black stripe. The tertials of females are shorter and that lack the black edging are immature. It seems more brownish and lack the black stripe. Immature lilcely that wings with new tertials growing after tertials of both sexes are similar and somewhat like November are immatures. those of adult females. Vermiculated scapulars are found only on males, but unvermiculated sca~ulars Age Determination of Females may be present on both males and females. The middle coverts of the immature plumage are Tertials and scapulars are useful for identibing rather narrow and somewhat trapezoidal. Any bar- some males, but not for separating the sexes in all ring of these feathers is largely made up of triangu- cases. lar patches at the feather edge. The middle coverts of adults are broad and rounded and any barring is Age Determination of Males made up of variable shaped patches recessed from The most useful character for separating the ages the feather's edge. is the condition of the middle coverts. These have The tertial coverts of the immature plumage are light edging on immatures and often appear narrow, very frayed, often poorly edged and individual and frayed. Some of these feathers persist through- feathers are often long and narrow. The tertial out the hunting season. On adult males, these coverts of adult-type plumage are not very frayed, feathers are not frayed and generally plain. About are well rounded, and have conspicuous edging.

I Wing Male I Female Character 1 I Immature I Immature Adult

I Underwing Gray; heavily flecked with white I Alternate brown and white bars

I Tertials I Acutelv oointed: brownish I Brown: most distal with 1 Brown with oale lonaitudinal I Bluntlv oointed: dark brown:

I I surrounding rachis I often frayed 1 frayed 1 brownish longitudinal stripe;

I I Middle and I Grav: without edaina: I Grav: liaht brown edaina at Brown with liaht edaina: 1 Brown with liaht edaina:

edging; somewhat 1 from edging; rounded trapezoidal Immature Adult f

Figure 42. Common middle covert markings of female northern pintail

Sex Determination and extends farther distally than on wings of imma- The white trailing edge of the secondaries on tures. females is much wider on the outer webs than on the inner webs. On males, this white edge is Age Determination of Females approximately the same width on both webs. On Immature tertials are pale bronze with pointed, females, the first secondary proximal to these white- usually frayed, tips. Immature tertial coverts are edged feathers is washed with black on the outer narrow and yellow-geen. Most immatures replace web. Males have no black on this feather. both tertials and tertial coverts with purplish red adult-type feathers by late October. Usually, the Age Determination of Males blue iridescence is confined to two rows of coverts Immature tertials are pale bronze with pointed, and is restricted to the proximal half of the imma- usually frayed, tips. Immature tertial coverts are ture wing. Adult coverts are somewhat wider and narrow and yellow-green. Most immatures replace tend to lie more smoothly on the wing. Dark blue both tertials and tertial coverts with dark blue usually extends onto the third row of coverts and adult-type feathers by late October. As the imma- extends farther distally than on the immature ture middle and lesser coverts are replaced by the coverts. adult-type plumage, the presence of a few dark blue feathers among the duller coverts indicates immatu- Note: rity. Usually, the dark blue does not extend onto the By mid-fall, some immature wood ducks hatched third row of coverts and is much restricted to the in the southern United States appear to have area anterior to the ~roximalhalf of the secondaries. replaced all of their immature upper-wing coverts. Generally, coverts of adults are somewhat wider and Their wings cannot be distinguished from those of tend to lie more smoothly on the wing and the dark adults. blue usually extends on to the third row of coverts

1 Male I Female I 1

, , blue-black; second most rounded tips distal white-edged at itstip After--I- molt: Similar to adult Ln-..l..After molt: Similar to adult

1 Other 1 Greater and middle coverts Greater coverts and middle Greater coverts often 1 Greater coverts usually 1 1

anteriorly over three or more confined to two rows of to two rows of cdverts three or more rows of rows of coverts coverts nearest secondaries anterior to secondaries coverts

I pa A~J) IOU pue papunod h~qloo~us sd!~:1~6 01 6u1peus'y3els

SEPARATIONOF REDHEAD AND CANVASBACK

Adult male canvasbacks have much more white secondary coverts and secondaries is greater on on the upper surface of their wings than any other wings of redheads of all age and sex groups than it is age-sex category of redhead or canvasback. All other on the wings of adult female or immature canvas- canvasbacks have much darker secondaries than backs of either sex. those of all redheads. Thus, the contrast between Immature greater coverts are narrower, squared, appearance of their tertial coverts. Several combina- often frayed to a point over the tertials with an tions are possible: 1) immature-type tertial coverts indistinct pale tip over the secondaries. During the always indicate an immature bird but sex is best hunting season, immature birds occasionally replace determined from other coverts; 2) adult male or both their immature tertials and greater tertial adult female-type coverts similar to the surrounding coverts with adult-type feathers. For a given sex, coverts indicate an adult of that sex; 3) adult male these new feathers are indistinguishable from those or adult female-type tertial coverts that differ from of adults but differ markedly from other immature the surrounding immature-type coverts indicate the greater and middle coverts which are retained. With sex of some immature birds. practice, redheads can be aged primarily by the

I Wing Male Female Character Adult 1 1 Immature I Immature 1 Adult

Broad, smoothly rounded Appear narrow, and usually have ragged pointed tips Broad, smoothly rounded and flecked or vermiculated After molt: Similar to adult After molt: Similar to adult male female

Figure 61. Immature female redhead

SEPARATIONOF GREATER AND LESSERSCAUPS

A white wing stripe normally extends onto the age class that are shorter than these measurements primaries on greater scaup but is confined to the are, in most cases, lesser scaup. secondaries on lesser scaup. There are exceptions. Because the two species are similar, the following The stripes may not conform on a few male lesser discussion pertains to both. Scaup differ from most scaup with unusually white wings or female greater other species of the same genus in that they rarely scaup with unusually dark wings. molt tertial coverts during the hunting season Approximately 94 percent of scaup wings can be (October-January). Other characteristics useful for correctly assigned to species using wing length, age-sex identification do not vary greatly, and once provided the age-sex class of each wing is known. a person has learned to recognize them, wings of The following points will identify greater scaup in scaup are relatively easy to classify. Although charac- each age class: adult males > 213 mm., adult teristics that separate ages and sexes are similar for females > 206 mm., immature males > 209 mm both species, they are not identical, and each is and immature females > 203 mm. Wings in each presented in a separate table.

1 wing 1 Male I Female 1 Character 1 / Adult I Immature 1 Immature I Adult I

1 I white near tios. tios oointed fleckina: tiosbointed. usuallv fleckina: tios oointed. usuallv without whiie fleckino 1

Middle and Black; all are well Black to dark brown with Black to dark brown, without Black to dark brown, plain or lesser vermiculated with white large white flecks to small white flecks; often ragged with very small white flecks coverts vermiculations recessed 118" and notched at tip concentrated near coverts' from coverts' edge; often edge; broadly rounded at tip raaaed and notched at ti0

Wing Male I Female Character L Adult I Immature 1 Immalure 1 Adult /~ca~ulars ' Heavily vermiculated; appear Lightly venniculated or flecked with whlte; appear more dark than white more white than black After molt Similar to adult After molt: No obvious I- male chanpe 1 -- Tertials Black, flecked to Black, barely flecked to well Black to very dark brown, Black to very dark brown; vermiculated with white; tips vermiculated with white; tips without flecks of white; tips without flecks of white; tips pointed and often drooping usually frayed to sharp point usually frayed to sharp point usually bluntly polnted

Middle and Black; all are well Black with large white flecks Black without white flecks; Tips broadly rounded and lesser vermiculated with white to small vermiculat~ons often ragged and notched at smooth; coverts black with coverts recessed 118" from coverts' tip small white flecks edge; often ragged and concentrated at tips or plain notched at ti^

Age Determination notch-length of 196 mm. or more are males and Ring-necked duck wings should be examined those with a notch-length of 188 mm. or less are under ideal lighting, preferably daylight rather than females. Immatures with wings 194 mm. or longer artificial light. A high fraction of immatures replace are males while those with wings 184 mm. or tertial coverts during the hunting season with shiny shorter are females. There are a few exceptions to black feathers that differ slightly from the very dark these measurements. There is too much overlap to brown of the other wing coverts. It may be neces- permit accurate sex determination of adults with sary to tilt a wing back and forth to see this differ- wings 189- 195 mm. long or immatures with wings ence. If no difference is apparent and all tertial 185-193 mm. long using measurements done. coverts are broadly rounded, the wing is from an Adult male tertials are shiny, greenish black and adult. If, however, the tertial coverts tend to narrow bluntly pointed. The tertials of adult females are toward their tips and/or appear frayed andlor similar but slightly less shiny, greenish brown and notched, the wing is from an immature. Many of broadly rounded. Males are usually flecked (often the middle and lesser coverts of immatures may also faintly) on the underwing over the radius and ulna. show notches. Females are rarely flecked in this area. All of these differences are slight and accurate sex determination Sex Determination is quite difficult. Because some immature males The sexes of approximately half of each age group resemble immature females, sex determination of can be identified from wing measurements provided immatures is not completely reliable. all primary quills have hardened. Adults with a

Wing Male Female Character Adult 1 Immature I Immature 1 Adult

Greater tertial Broadly rounded, dark Dark brown to blackish; usually narrow slightly to ragged tips Broadly rounded, dark ' coverts blackish brown After molt: Similar to adult After molt: Similar to adult male female

White flecking present on small coverts near leading edge of Small coverts near leading edge brownish, with white edging, 1 Underwing 1 wing most pronounced near body 1 rarely with trace of white flecklng Notch-length 88% > 193 mm. 8896 88% c 192 mm. 1 .- f r 189 mm. 1 86% < 189 mm. 1

Species Identification Age and Sex Identification I The black bases of most greater secondary coverts Adult males of each species are sufficiently dis- on Barrow's goldeneyes extend over more than half tinctive to be easily identified. Adult females of of each feather and are visible on a normally spread both species have a broad black band across the tips wing. On common goldeneyes, these black bases of the greater secondary coverts. Immatures of both i cover less than half of each feather and are normally species have greater secondary coverts with white or hidden (Figure 79). Usually the outer vanes of less variably spotted tips (not banded) that are often than 7 secondaries are white on Barrow's slightly frayed. The sexes of immatures appear simi- goldeneyes, but on common goldeneyes outer vanes lar, but 95% may be identified on the basis ofwing of 7 or more secondaries are white. length.

Wing I Immature I ~du~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 Black, tips rounded and not Black, somewhat pointed, often both frayed and faded at tips Black; tips rounded and I 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

Wing Male Chancier d 1 1 I Immature +m&? Adult

I secondary sometimes with black show as a narrow band band across tips; black coverts 1 tipping; bares form a broad bases show as a narrow 1 black band band - -- 1 Notch-length 1 97% w 222 mm. 1 96% > 217 mm. 94% < 217 mm. 1 96%

Although whole birds are quite easy to tell apart, white strips, and the white on their secondaries is detached wings of some sex and age groups appear restricted to the feather edges. In contrast, buffle- superficially similar. There are, however, two char- head tertials are solid black, and the white on their acteristics useful for separating the two species. secondaries extends to the feather shafts. Hooded mergansers have black tertials with central

Figure 88. Variation in the tertials and secondaries between the hooded merganser (left) and the bufflehead (right) Wings of adult males have greater, middle, and females next. They have smoothly rounded greater many lesser coverts that are entirely white. Wings of coverts over both secondaries and tertials and their adult females and immature birds of both sexes have tertials often droop to rounded tips. The remaining only a few white greater- coverts and no white mid- wings are from immature birds and their greater dle or lesser coverts. Wings in the second group that coverts are usually frayed and somewhat pointed at are 165 mm. or longer are all from immature males their tips and their tertials appear straight with and include about two-thirds of them. Wings- 164 brownish fraying at their tips. Wings in this group mm. or shorter include the adult females, immature that are 160 mm. or longer are from immature females, and the remaining immature males. The males and those that are159 mm. or shorter are easiest sequence to follow is to identify the adult from immature females.

Wing Male 1 Female Character 1 ~du~t TKa-Ure

' Greater Entirely white; tips smooth Vary among individual birds; 1 Vary among individual birds Vary among individual birds secondary usually many white spotted; from well spotted with white from black with or without tips usually frayed to entirely black; tips usually few white spots to white with black band at tips; tips I frayed smooth - i99%< NO=&^ 93% > 165 mrn >98%> 16xm.- 97$b i160mrn--- - 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 Age Determination Adult males have shiny black, unfrayed tertials Immatures are similar in gross aspect to adult with longitudinal white stripes and light gray mid- females, but immature tertials are straight and dle and lesser coverts. Adult females have shiny frayed at the tip and often appear brown. The mid- black tertials with longitudinal white stripes, which, dle and greater coverts usually are frayed and while tapering (as in males), are slightly shorter and brown, particularly over the tertials. These feathers blunter. The middle coverts of females are a black- are smooth and unfrayed on adults. ish brown to grayish. 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.

1 wing I Male 1 Female Character 1 I Adult 1 Immature 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 dfIfinsiand-. frequently wiM dark edging

tips often ragged and frayed over secondaries brown but slightly paler distallv

SEPARATIONOF RED-BREASTEDAND COMMONMERGANSERS

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-BREASTEDMERGANSER

Greater tertial Most are white with All are dark gray-black and taper to tips which are usually All are shiny black with I coverts 1 smoothlv rounded LDS 1 fraved 1 smoothlv rounded IDS 1 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 ...... Surf scoter

(a) (b) (4 Black Scoter Oldsquaw Surf Scoter

Figure 103. Variation in the outer rwo primaries among three species 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~ale 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 ] -. . . -- . - - - - ... . - - I 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 - -1I

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 WingCharacter F- 1 Female / Immature 1 Immature ( Adult Not attenuated but noticeably narrower and shorter than the next primary than adjacent primary -- -. -- . -- -- . -- - . - -. -. . - Shiny black and acutely Dark brown and sharply pointed; often faded at their tips Very dark brown and bluntly 11 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; nzwslightly toward their tips which are Dark brown; with rounded tips //IpS-gy frayed and faded , , .. . - .- black with rounded Dark brown; greater coverts often slightly faded near tips; Dark brown; may be faded at their tips coverts I appear 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. Ti- Character ------7Immature Immature I Adult--I

Tertials Shiny black and bluntly Dark brown and pointed; may be faded at their tips Very dark blackish brown; pointed; approximately 20 tips bluntly pointed; usually rnrn. longer than most less than 20 rnrn. longer secondaries 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 and the outer half of their greater coverts which are Immatures of both sexes are generally a lighter white. The sharply defined black bases of the sec- brown than adult females, but do intergrade some- ondary coverts create a saw-toothed appearance. what. On immatures, the tertials and tertial coverts There is no evidence of fading or fraying on either usually have some faded fraying at their tips. Similar tertials or tertial coverts. Adult females are similar light-colored fraying is often present among the except that the uppenving is a very dark brown scapulars. The greater coverts often have much less rather than black. It may be necessary to tilt the white at their tips than those of adults and some- wings and view them closely to see that they are not times they are entirely brown. black. Approximately 90% of adult females have a notch-length of less than 274 mm. and approxi- Sex Determination of Adults mately 90% of adult males are longer. Adult males can be readily identified by the black of all uppenving feathers except for the secondaries

Female Character 1 (lmmxre 1 Immature 1 Adult , .- - - I Tertials 1 !arbtips are blunt and rounded -I...... -. . . -. - - I

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.

Wing Male Female Character Adun 1 Immature I Immature 1 Adult

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

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 ed~in~

I 1 Wing Character 1 Adult 1 Immature Tertial coverts L8madly rounded at tips 1Somewhat squared at tiKappearing trapezoidal. I L - -. - . I I Tertials 1 Broad-tipped, curved and drooping I Straight, often somewhat frayed at their tips

~kG&i'S--~untied and smoo&-edged . Slightly- - trapezoidal, - - .. often- - rough-ended- . .- .. . . - . .

Wino Character Adult Immature 1 - 1 I 1 / Greater coverts 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

[ ~essercoverts 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 I 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.shoveler (part) 13(b). Primary shafts brown; norch-length 205 mm. or shorter ...... Blue-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

I light edged with internal patterns; underwing white ...... Gadwdl

I 18(b). Most secondaries white, banded with black near their tips; upperwing covert 1 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 ...... Getscaup I 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...... it-winedscoter 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 I 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 ...... Ring-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

I 29(a). Secondaries black or mostly so ...... 30 I 29(b). Secondaries brown or brownish ...... 34 I 30(a). Tertials white or mostly so ...... Common eider (part) 30(b). Tertials black, olive, or mostly brown ...... 31 3 1(a). Tertials black...... 32 I 3 1(b). Tertials olive or mostly brown ...... 33 32(a). Tertials sharply curved; middle and lesser coverts black, i black and white, or white ...... Kgeider (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; I underwing black ...... Black-bellied whistling duck I 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 I 35(a). Trailing edge of secondaries white; greater coverts light edged ...... 36 I 35(b). Trailing edge of secondaries washed with buff ...... 38 I 36(a). Tertials brown, longitudinally striped, and pale edged ...... N. pintail (part) 36(b). Tertials brown, edges washed with cinnamon ...... 37 'q3EqSEAUE3 JJnlEUIUl! jo saxas yloq pue apuraj 11npejo asoql ueql XeJS ~alqS!lX1qaz!uSo3a~ JJE speaqpaJ Ilejo eln~dsaqL , .aaJe s!ql u! 3x1 aJe symp q9qq UE~!J~T .sexaL apnpu! 01 IS~Mlseo3 31n3 aql pue ep!JoId u~aq~nosu! Xluo mmo symp paplol/y I

(, (, Menbspl ...... gnq al~dql!~ paqseM IlaM UMOJ~yep suaAo3 Jassa] pue alpp!l/y .(q)g$

(IJE~)Jap!a uoururo=>...... Bu!Spa,tjnq pauyap-lla~auros ql!~UMOJ~ yep SJJ~AO~Jassal pue alpp!l/y '(e)gc pJed) Jap!a uoururo=> ...... pamn3 XpqS!p spp-raL -(q)~$ ped) Jap!a Su ...... pamn:, Xld~eqsspp~a~ '(e)~$ National Wetlands Research Center Library