- Ardetta eurhythma Swinhoe, Ibis (1873), 74, pl. 2; Meyer and Wiglesworth, Birds of Celebes (1898), 2, 856, pl. 45.
- Nannocnus eurythmus Sharpe, Cat. Birds Brit. Mus. (1898), 26, 242; Hand-List (1899), 1, 203; Oates, Cat. Birds’ Eggs (1902), 2, 133; McGregor and Worcester, Hand-List (1906), 35.
Mindanao (Bourns & Worcester); Negros (Keay). Eastern Siberia, China, Japan, Borneo, Celebes.
“Adult male.—Above chestnut-brown; lesser wing-coverts and feathers round bend of wing also chestnut-brown; alula-feathers chestnut, outer ones blackish internally, with white on the outer margins; remainder of wing-coverts olive-clay-color, ashy near the ends of the feathers, innermost greater-coverts chestnut like scapulars; innermost secondaries also washed with chestnut, remainder of quills and primary-coverts ashy brown, paler at the tips, which are fringed with whitish, the first primary margined with ocherous; tail dark brown; crown and nape dusky brown; sides of face, ear-coverts, and neck-frill maroon; a broad band of white running from the middle of the cheeks down the sides of the neck; fore part of cheeks, throat, and under surface of body ocherous-buff; under tail-coverts, under wing-coverts, and axillars white; on the throat some slight indications of longitudinal dusky spots; feathers of the fore neck elongated; on each side of chest a patch of black feathers with ocherous margins. ‘Bill blackish brown on culmen, yellowish brown on the rest, darker on the sides of upper mandible near tomia, light on sides of lower and on gonys; cere and bare skin round eye purplish flesh-color, ringed with green; legs and toes grass-green, yellow near the tarso-tibial joint and on the under surface of the tarsus; soles clay-colored; claws light yellowish brown; iris straw-color.’ (Swinhoe.) Length, 305; culmen, 50; wing, 150; tail, 39; tarsus, 51.
“Adult female.—Different from the male. Dusky reddish brown, spotted all over with ocherous-buff, the feathers externally spotted or notched with this color; wing-coverts like the back, but largely edged and spotted with ocherous; head like the back; sides of face dull chestnut, with a band of white from the hinder cheeks down the sides of the neck; under surface of body ocherous-buff, plentifully streaked with blackish brown, tinged with rufous; the lower abdomen and under tail-coverts whiter; under wing-coverts deep ocherous, with ashy bases; a patch of brown feathers at the sides of the breast, all edged with ocherous. Length, 305; culmen, 49; wing, 140; tail, 29; tarsus, 48.
“Young.—Like the old female, but blackish brown above, the wing-coverts maroon-chestnut, and all the upper parts spotted with white instead of ocherous. ‘Bill bright yellow, tinged with green; culmen black; feet yellowish green; iris golden yellow.’ (Everett.)” (Sharpe.)
“A single specimen secured by us while with the Steere Expedition has been identified by Grant as Ardetta eurythma.” (Bourns and Worcester MS.)
Genus DUPETOR Heine and Reichenbach, 1890.
This genus appears to be very near Ixobrychus but it may be recognized by the blackish or slate-colored upper parts.