Calayan (McGregor); Mindoro (McGregor); Luzon (McGregor, Worcester). North America, Europe, and western Asia; wintering in Africa, Arabia, Persia, Indian Peninsula, southern China, Hawaii, West Indies, and Central America to Colombia.
“Adult male.—Head and upper part of neck dark glossy green; lower neck, breast, and anterior scapulars white; middle of back dark brown, the feathers with pale edges; ramp and upper tail-coverts black glossed with green; lower breast and abdomen rich chestnut; flanks, vent, and thighs paler, freckled with brown; under tail-coverts black, glossed with green; a white patch on the lower flanks at the base of the tail; upper wing-coverts and the outer web of two of the longer scapulars pale blue; remainder of the scapulars black, all with a broad silky white stripe along the middle; last row of wing-coverts tipped with white, forming a band, which borders anteriorly the glossy green wing-speculum; tip of the secondaries and the primaries brown; under wing-coverts and axillars white; tail mostly white, freckled with brown-gray, central feathers brown, edged with white. Iris yellow; bill lead-color; feet reddish orange. Length, about 508; wing, 260; tail, 95; culmen, 70; tarsus, 35.
“Female.—Upper parts brown, each feather with a broad reddish margin; throat reddish immaculate; feathers of back and scapulars with reddish bars, more or less crescentic; under parts reddish buff, each feather brown in the central part, especially those of breast and flanks; under tail-coverts lighter; wings resemble those of the male, except that the blue on the wing-coverts is very dull and the speculum not so glossy; tail-feathers whitish, with brown marks. Beak olive-brown, base of the maxilla and the entire mandible orange; iris hazel-brown; feet dull orange.
“Male in first plumage resembles the female, but the wings are brighter colored. Bill pale reddish brown; legs and feet flesh-color.
“Males in their first nuptial plumage have the white of the breast with a few dark crescentic bands, the lower belly with dark bars, and the rich black of the under tail-coverts mottled with chestnut and white.
“Adult male in molting plumage may be distinguished from the adult female by the greater brilliancy of the blue and metallic green on the wing, the plain dark upper tail-coverts, and the general darker color of the entire plumage; the crown is dark brown.
“Young in down resemble those of the wigeon in having the upper parts almost uniform, with indistinct pale spots, but they possess the dark brown stripe through the eye as in the young mallard. The bill is not widened at the tip, but it grows very rapidly.” (Salvadori.)
This duck may be recognized in any plumage by the shape of its bill.