Appearance

No complete quantitative study of molts and plumages. Descriptions below for H. m. mexicanus based on Bent (1927), Palmer (1967), Jehl (1968), Prater et al. (1977), James (1991), Paulson (1993) and salvaged specimens of JAR and LWO. Colors, when capitalized, follow Smithe 1975 . Ridgway (1919) noted that females from Florida (n = 5) had back and scapulars that were a “darker grayish brown” than those from the w. U.S. (n probably = 4), but it is unclear whether these differences apply to Definitive Basic, Definitive Alternate, or both plumages.

Hatchlings

Completely downy; upperparts Light Drab (119C), finely mottled Drab Gray (119D), with a broken Sepia (219) streak down crown and back. In some individuals, two Sepia lines extend from the shoulder region toward the rump, in others the lines fuse at the mid-back and continue toward the rump as a single stripe (Jehl 1968). Various Sepia and Jet Black blotching and spotting on crown and back. Sides of head and neck paler and unmarked. Underparts creamy whitish, nearly pure white on belly.

Juvenal Plumage

Prejuvenal molt begins at approximately 3 wk, but development rates can vary greatly at different sites. Development begins first on the scapulars, back and breast; last on the tail. Molting especially pronounced in crown and nape throughout molt.

Similar to Definitive Basic female but dark areas finely mottled with Drab Gray or dull white, back and wings have Drab Gray or Flesh Ochre (132D) feather margins, inner primaries and secondaries Sepia with white tips forming white line along rear edge of wing when open. Sexes similar.

Basic I Plumage

Prebasic I molt partial; body plumage replaced (contra Bent 1927), but degree to which body plumage replaced unknown, a few wing-coverts and tertials replaced but most retained. All juvenal primaries and secondaries probably retained.

Male. Similar to Definitive Basic male except black feathers, particularly on head and hindneck, tinged Sepia, and some have white or whitish tips that grad-ually wear away. White tips on retained Juvenal secondaries and inner primaries also gradually reduce through wear.

Female. Similar to Basic I male except dark areas more brownish.

Alternate I Plumage

Prealternate I molt incomplete, molt includes some body feathering and probably some flight feathers. Timing of molt unknown, probably before or during Mar, as in Definitive Alternate, but may extend later into the summer (Paulson 1993).

Male. Similar to Definitive Alternate male with new plumage characterized by metallic sheen on black areas, but part of black feathering with light tips (Palmer 1967). However, males in this plumage may not be distinguishable from Definitive Alternate males in all cases.

Female. Similar to Definitive Alternate female except dark feathers of head, nape, and upperparts intermixed with some white or Pale Neutral Gray (86) feathers.

Definitive Basic Plumage

Definitive Prebasic molt probably complete; occurs Aug and Sep, probably during or after migration, but Paulson (1993) noted wing molt on breeding grounds. Palmer (1967: 152) noted that the second Prealternate molt might not in fact produce the Definitive plumage and hypothesized that the species might undergo 2 Prealternate molts before achieving Definitive plumage in which “dark areas are uninterrupted by any light markings.”

Male. Similar to Definitive Alternate male except black areas without gloss and tinged Sepia on back of head and hindneck, breast without pinkish tinge, and tail Sepia with grayish tinge.

Female. Similar to Definitive Alternate female except dark feathering more muted in coloration.

Definitive Alternate Plumage

Definitive Prealternate molt probably partial, includes at least some back, scapular and breast feathers; timing uncertain, probably during Mar, before spring migration.

Male. Top of head (except forehead) extending to just below eye, through back of neck, back, scapulars, and upper surface of wing Jet Black, lower surface of wing also Jet Black except for white basal lesser underwing-coverts and axillars; tail Pale Neutral Gray; spot extending back and up from eye, forehead, sides of head below middle of cheeks, remaining underparts, and lower back through uppertail-coverts white. Black feathering with slight greenish-blue gloss, and white breast feathers often tinged slightly with Pale Pinkish Buff (121D).

Female. Similar to Definitive Alternate male except dark areas somewhat paler and without gloss, head and neck noticeably paler (towards Sepia), back, scapulars, and tertials sepia to Grayish Horn color. Underparts white without pinkish tinge.

Hawaiian Stilt

Basic I plumage has dark patterning on head and neck that resembles female Definitive Alternate of mexicanus . Definitive Basic and Definitive Alternate males and females have more black along sides of neck and cheeks. Female has somewhat more black on cheeks and forehead than mexicanus female, while male is even more extensively black in these areas and has more black on sides of neck, extending slightly onto upper breast. White spot above the eye varies among individuals from large to nonexistent, and does not differ between sexes (Coleman 1981). Uppertail-coverts tipped blackish. Tail grayish with grayish-black tip (darker than on mexicanus); outer margins of the feather tips gray, inner margins white, except middle pair which has both margins gray (Stejneger 1887).

Bill And Gape

Bill Jet Black, often dulled by thin film of mud.

Iris

In male Red (at its brightest probably Spectrum Red, 11). Less vivid in Definitive Basic plumage than in Definitive Alternate plumage. Female iris less vividly colored than male. Sometimes brownish next to pupil. Iris color of juveniles brown (Hawaiian Stilt, Telfer 1972, Telfer 1973).

Legs And Feet

Legs and feet slightly muted Ruby (10); small hexagonal scales all around. Legs and feet of female less vivid than male, also less vivid during Definitive Basic plumage than during Definitive Alternate. In young flighted birds (Basic I) legs light pink, however Telfer (1973) noted that leg color was not a reliable indicator of age in Hawaiian Stilts. Feet unwebbed except a small bit of webbing between outer and middle toes; hallux absent.