Appearance

Molts And Plumages

Most of this section (and also Bare Parts, below) based on Ridgway (1919), Dement'ev and Gladkov (1951), Roberts (1955), Stresemann and Stresemann (1966), Palmer (1967), Oberholser (1974), Prater et al. 1977, Pym 1982, Cramp and Simmons 1983, Johnson and Johnson 1983, Johnson 1985, Hayman et al. 1986, Dunn et al. 1987, Roselaar 1990, Golley and Stoddart 1991, Marchant and Higgins 1993, Paulson 1993, Paulson 2005, Pyle 2008, and unpublished findings (OWJ). Of these sources Dunn et al., Golley and Stoddart, and Paulson contain particularly helpful photographs of the two species (both sexes) in the plumages described below. For additional photos, see Rosair and Cottridge (1995), Johnson and Johnson (2004), O’Brien et al. (2006), and Chandler (2009). Treatment by Byrkjedal and Thompson (1998) complements our descriptions below, and also includes useful diagrams and sketches. See Pyle (2008) for detailed information on molt and age determination. See Dwight (1900) and Stone (1900) for early accounts of molt.

Golden-plovers have 10 functional primaries, 11 functional secondaries, 3-5 tertials, and 12 rectrices. Plovers are diastataxic (see Bostwick and Brady 2002) indicating that a secondary has been lost evolutionarily between what we now term s4 and s5. Wings are long and pointed and tail is short and squared. Geographic variation in appearance within each species slight at best (see Systematics: Geographic Variation). No intraspecific geographic variation in molt strategies reported, although variation is marked between the two species, as summarized below.

Molt and plumage terminology follows Humphrey and Parkes (1959) as modified by Howell et al. (2003, 2004). Golden-plovers exhibit the Complex Alternate Strategy (cf. Howell et al. 2003), including complete prebasic molts, a partial to complete preformative molt, and limited to partial prealternate molts in both first and definitive cycles. A Definitive Presupplemental Molt of flank feathers has been reported in Pluvialis (Jukema and Piersma 1987, Byrkjedal and Thompson 1998, Jukema et al. 2003) but confirmation needed (see Pyle 2008 and below). Definitive plumage typically attained following the Preformative Molt in American Golden-Plover and following the Second Prebasic Molt in Pacific Golden-Plover.

Hatchlings

Natal down well developed at hatching. In American Golden-Plover, crown and back overall yellowish, mottled with fine black markings; except for crown and black malar stripe, remainder of head, also throat and nape, solid whitish; underparts grayish white (Bent 1929, Van Tyne and Drury 1959, Jehl 1968, OWJ). According to Parmelee et al. (1967), American Golden-Plover chicks are dimorphic with females having “pronounced golden pectoral band that is lacking in the males.” Similar pattern of markings in Pacific Golden-Plover, except more yellow throughout; yellowish especially noticeable around head, nape, and throat (Bent 1929, Conover 1945, OWJ). Whether sexes dimorphic uncertain. Jehl (1968) suggested that disruptive pattern of prominent whitish nape band (“collar”) in American Golden-Plover might be favored by selection, particularly where chicks are exposed amidst very low vegetation.

Prejuvenal (First Prebasic) Molt And Juvenal Plumage

Prejuvenal Molt complete, late Jun-Sep, as young mature and forage on the tundra. Primary flight feathers erupt at approximately 6 d of age; see Breeding: young birds/growth and development. Prejuvenal molt progresses rapidly, fledging in <30 d (see Breeding: young birds, above); crown, mantle, back, scapulars, and tertials dark grayish-brown, feathers marked with yellow edges and spots; lesser and median wing-coverts same background color with whitish, buffy, and yellowish markings; breast, sides, and flanks grayish white with grayish-brown barring, latter heaviest on breast and becoming finer and less dense on flanks; belly and undertail whitish; dark auriculars produce conspicuous postorbital patch; lores moderately dark forming less prominent loral smudge (best developed in American Golden-Plover); primaries, secondaries, and greater-coverts dark grayish-brown; one-half to two-thirds of subterminal primary rachises white (especially conspicuous on outer 5–6 primaries), outer vane of primaries uniformly dark, inner vane dark distally shading to whitish brown proximally; wing coverts whitish on tips (foregoing features of remiges and coverts also characteristic of adult feathers); rectrices grayish brown faintly barred dark brown, small lateral yellow spots, and yellow-fringed tips.

American Golden-Plover has prominent whitish supercilia; cheeks and neck spotted and streaked with dirty white and brownish gray; chin whitish; chest gray, mottled and spotted with grayish brown. Pacific Golden-Plover shows brighter yellow (in possibly larger spots) on dorsum; head, neck, and chest yellowish and buffy where American Golden-Plover whitish and grayish (see color plates in Hayman et al. 1986 and color photographs in Dunn et al. 1987, Golley and Stoddart 1991, and Paulson 1993).

Preformative Molt And Formative Plumage

"First prebasic" and/or "Basic I" molt and plumage of previous authors. Preformative molts differ in extent between species (Johnson and Johnson 1983, 1985; Pyle 2008):

in American Golden-Plover complete, Oct-Mar/May and in Pacific Golden-Plover partial-incomplete, Sep-Dec/Mar. Some American Golden-Plovers may occasionally retain 1-4 juvenal medial secondaries (probably among s3-s4 and s7-s10). In Pacific Golden-Plover the molt includes some to all body feathers, some to most secondary coverts, often 1-5 tertials, and some rectrices (see below), but no primaries, outer secondaries, or primary coverts (Pyle 2008). Rectrix molt variable and disorderly—some birds replace all rectrices, others very few, some have Juvenal sixth rectrix still in place. In both species molt occurs primarily or entirely on the wintering grounds. In Pacific Golden-Plover molting appears to start after arrival in Hawaii; duration about 2.5 mo, from Oct to early Dec. Juveniles traveling very long distances (into s. Pacific, etc.) perhaps in molt before arrival on wintering grounds. These individuals probably have more-extensive Preformative Molts, which may include outer primaries in an eccentric pattern in occasional individuals, as in other shorebirds that migrate to Southern Hemisphere (Pyle 2008).

Formative Plumage similar to Definitive Basic Plumage except for aspects related to retention of juvenal feathers in Pacific Golden-Plover. Distinctive Juvenal breast to flank barring lost by early winter, after which plumage closely resembles Definitive Basic. Age determination possible with Pacific Golden-Plover in hand: Juvenal primaries not molted (Johnson and Johnson 1983, Barter 1988, 1990), Pyle (2008), thus become progressively worn; most Juvenal wing-coverts, some tertials and rectrices also retained. Outer rectrices (sixth pair) helpful as age criterion since Juvenal feathers are drab and unbarred in about two-thirds of individuals, other one-third with variably barred, often adult like feathers (Johnson and Johnson 1983). Limited observations suggest similar morphology of outer rectrices in juvenile American Golden-Plovers (OWJ). Significant changes occur with fading, and these can be misleading (Marchant and Higgins 1993, Paulson 1993). Age determination not possible with American Golden-Plover following completion of Preformative Molt.

First Prealternate Molt And First Alternate Plumage

In both species First Prealternate Molt limited to partial, Mar/Apr-May/Jun, probably averaging later in American than Pacific golden-plover. Much of this molt (and subsequent Prealternate molts) occurs while American Golden-Plovers are en route north. Similarly, Pacific Golden-Plovers wintering in Australia depart in partial breeding plumage then molt during migration (Barter 1988). In Hawaii, birds usually complete molt before departure.

In American and some Pacific Golden-Plovers extent of First Prealternate Molt can approach that of Definitive Prealternate Molt while in some Pacific Golden-Plovers, particularly those that remain on winter grounds for first summer, molt can be limited to just a few body feathers or perhaps rarely can be absent. General features of Pacific Golden-Plover First Prealternate Molt on Oahu, HI (Johnson and Johnson 1983, OWJ): occurs from end of Jan to early May, with individual duration varying considerably within this period; replacement of body feathers and wing-coverts variable, ranging from almost complete to none; over-summering birds average less molt. One to four tertials and/or one to two central rectrices occasionally replaced but averages fewer feathers and less frequently than in Definitive Prealternate Molt. Less molting also possible in over-summering American Golden-Plover, as well.

First Alternate Plumage aspect varies from nearly that of Definitive Alternate through varying degrees of partial Alternate to resembling retained Formative Plumage. Banding studies on breeding grounds (OWJ) and examination of migrants (Johnson 1985) indicate that First Alternate Plumage of American Golden-Plover similar to Definitive Alternate Plumage (contra Hayman et al. 1986, who report “little or no black on underparts” of first-year birds). Sexes dimorphic (see Second and Definitive Alternate Plumages, below; also Distinguishing Characteristics, above), but appearance sometimes misleading in Pacific Golden-Plover (possibly in American Golden-Plover) due to partial or limited molts in both sexes. Wing-coverts and tertials often confusing as age (and species-identification) criteria since variable number of Juvenal, Formative, and/or First Alternate feathers retained by some birds, replaced by others. In Pacific Golden-Plover worn juvenal outer primaries are retained in most birds and these can be used to distinguish second-summer birds following migration to winter grounds.

Definitive Prebasic Molt And Definitive Basic Plumage

Second and later Prebasic molts complete or nearly so. In Pacific Golden-Plover Second Prebasic Molt averages earlier in timing, especially for over-summering one-year old birds. Primaries replaced distally (p1 to p10), secondaries replaced proximally from s1 and s5 and distally from the tertials, and rectrices probably replaced distally (r1 to r6) on each side of tail, with some variation occurring.

For breeding birds both species start Prebasic Molt on breeding grounds during incubation (Fig. 4). Early stages of molt most noticeable on black cheeks and underparts which become mottled with lighter feathers. Describing less colorful male Pacific Golden-Plovers in Prebasic Molt on breeding grounds, Sauer (1962) mistakenly used term “eclipse.” Supplemental feathering with possible cryptic function has been described on underparts of breeding Eurasian Golden-Plovers in both sexes (Jukema and Piersma 1987). Whether ventral body molt of nesting American and Pacific golden-plovers involves like elements or simply represents late Prealternate Molt or early Prebasic Molt is unclear (Jukema et al. 2003, Pyle 2008).

On Siberian breeding grounds, more than half of Pacific Golden-Plovers have begun Prebasic Molt by end of Jul (Kistchinski et al. 1983), body molt begins early in incubation, and adults often molting inner primaries by mid-Jul (Schekkerman and van Roomen 1995, Byrkjedal and Thompson 1998, Tulp et al. 1997, 2000, P. Tomkovich in litt.). These observations consistent with condition of Pacific Golden-Plovers arriving on winter range: many birds wearing only traces of Alternate body feathering, often with suspended primary and rectrix molt. Individual duration of body molt approximately 2.5–3.5 mo (variable from late Jun through mid-Oct); primary molt more protracted, requiring 4–5 mo (completed in most birds by early Dec); over-summering birds begin primary molt in Jun or Jul, several weeks earlier than migrants. Among Pacific Golden-Plovers wintering in Australia, average duration of primary molt also about 4 mo, but timing later (Oct–Mar) than in Hawaii (Barter 1988).

American Golden-Plover differs from Pacific Golden-Plover in that fall adults at James Bay, Canada, showed partial body molt only, no evidence of suspended molt of primaries or rectrices (Morrison 1984); possibly less body molt prior to arrival on the winter range (Dabbene 1920, Hudson 1920, Haverschmidt 1969, Belton 1984, Hayes et al. 1990, Sick 1993). In addition, molt more protracted on South American winter grounds, often or usually extending into Feb-Mar, as is typical of Southern Hemisphere shorebirds that lack time constraints on molt (Pyle 2008).

During Prebasic Molt, males and females progressively less dimorphic. In Basic Plumage, American Golden-Plover has prominent whitish supercilia, sides of head grayish with darker auriculars and loral smudge; upperparts including crown dark grayish-brown with yellow, buffy, and whitish spots and fringes; chest, breast, sides, and flanks mostly grayish brown with slight wash of pale yellow; belly and undertail whitish. Pacific Golden-Plover similar to American Golden-Plover except more yellow, especially obvious from head to breast; rectrices (pairs 1–5) barred light/dark grayish-brown; outer rectrices (pair 6) about 80% sexually dimorphic with crisply defined dark gray/grayish white or black/white bars indicating males, and less defined (more somber) coloration indicating females.

Definitive Prealternate Molt And Definitive Alternate Plumage

Second and Definitive Prealternate Molts similar in timing and extent, partial, Jan-May, primarily on winter grounds but can complete at stopover sites or on summer grounds in some Pacific and most American Golden-Plovers. Includes some to most body feathers, up to 90% of secondary coverts, often 1-5 tertials, sometimes 1-2 (occasionally 3-4) central rectrices (occasionally asymmetrical with 1 rectrix of a pair fresh and the other old); males average greater number of feathers, e.g., in females typically only as much as 40% of wing coverts replaced (Pyle 2008). First birds to begin and complete Prealternate Molt usually males, with some males achieving full Alternate aspect in about 10 wk.

Typically Second Alternate Plumage similar to Definitive Alternate plumage, but a few birds require an additional cycle, and Alternate Plumages of some individuals progressively more extensive in successive cycles, with up to 3 yr before Definitive Alternate is acquired. In males, American Golden-Plover has background of dark grayish-brown on crown, nape, mantle, scapulars, tertials, and wing-coverts with spots and fringes mostly yellow, some buffy; continuous white marking from forehead through supercilia, down sides of neck to widened, bulbous breast patches which in some birds almost meet on the midline; base of bill, chin, throat, cheeks, medial chest and breast, sides, flanks, belly, and undertail black (a few birds with scattered white feathers in undertail); primaries dark grayish-brown, rectrices barred light/dark grayish-brown; Pacific Golden-Plover similar to American Golden-Plover except upperparts more yellow, white breast patches much less bulbous with white continuing along sides and flanks, black frontal band above base of upper mandible possibly narrower; undertail-coverts predominantly white (small percentage mostly to entirely black; Golley and Stoddart 1991, OWJ).

Females of both forms show black feathering of face and underparts mottled with whitish grading into white head-neck stripe, thus latter less clearly defined than in male; females often have distinctive white cheek patches. Occasional American Golden-Plover female dark and male-like (Connors et al. 1993), but feathering usually brownish black instead of jet black as in male (OWJ).

Male-like coloration rare in Pacific Golden-Plover females (contra Marchant and Higgins 1993, who report “substantial overlap between sexes”), and darker individuals generally show white feathering on cheeks (OWJ). Sauer (1962) noted one instance of “male-like plumage” among female Pacific Golden-Plovers on St. Lawrence I. Although Nelson (1887) described these plovers as sexually dimorphic in Definitive Alternate Plumage, the notion that sexes were alike persisted in early accounts (e.g., Ridgway 1919, Allen 1934) and surprisingly in a later treatment (Johnsgard 1981). Differences between male and female Alternate plumages (both species) were set forth by A. C. Meinertzhagen (see Witherby et al. 1940) and confirmed in subsequent field studies (Van Tyne and Drury 1959 for American Golden-Plover, and Sauer 1962 for Pacific Golden-Plover).

That Pacific Golden-Plovers are generally yellower than American Golden-Plovers is emphasized throughout the above descriptions. Possible factors producing this difference include more intense pigmentation, larger markings, and greater number of markings. Paulson (1993) examined Alternate plumage mantle feathers and concluded that the main variable was number of markings: 1 pair of yellow apical spots/typical feather in American Golden-Plover, 2 pairs (apical and lateral) in Pacific Golden-Plover. This relationship was not apparent among birds captured for banding in w. Alaska; mantle feathers of both species often had 2 pairs of spots, with possibility that feathers having only apical spots are more frequent in females (OWJ). See Distinguishing Characteristics, above, for additional comments on morphological characteristics of each species.

Bare Parts

Following applies to both species.

Bill

Black in all ages, including hatchlings.

Iris

Dark brown throughout life.

Legs And Feet

Dark grayish brown to gray in hatchlings. In older birds, vary from gray and grayish black to black. Gray and grayish black seem to occur most often in juveniles (OWJ)

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