"Adult males in winter appear to be a little more dingy on the upper parts than in summer, the head and back being shaded with grayish brown.
"Adult female.--Mantle and back uniform dark brown; wing-coverts dingy brown, but mottled with sandy-buff margins and checkered notches, which appear also on scapulars and inner secondaries, and have also subterminal markings of darker brown on many of the coverts; greater coverts, primary-coverts, and quills chestnut, with a good deal of dusky at base and on the inner webs, primary-coverts also dusky towards the ends; tail-feathers dull chestnut; crown and nape dusky brown; frilled feathers on the sides of neck brown in the center, with yellowish margins; sides of face yellowish buff, streaked with brown; whole of the under surface yellowish buff, very thickly streaked with dark brown, sides of throat whiter, feathers composing the broad mesial streak down the middle of throat and fore neck having a distinct rufous shade; on each side of the upper breast a patch of dependent plumes, black in the center with yellowish-buff margins; thighs chestnut; under wing-coverts yellowish buff like the chest; axillars and quill-lining dull chestnut, the feathers with a good deal of gray in them. 'Facial skin, margins of upper mandible, and nearly the whole of the lower mandible yellow, remainder of bill black; back of tarsus and soles yellow; claws yellowish brown; iris yellow.' (Oates.) Length, 330; culmen, 51; wing, 136; tail, 43; tarsus, 44.
"The young birds are very like the female, as determined by Mr. Oates and myself, but the whole back is variegated with yellowish-buff spots and markings, as well as the wings, so that the uniform brown mantle is a sign of the adult female, and the spotted mantle of a young bird. Mr. Everett gives the soft parts of a young female as follows: 'Legs and feet bright olive-green; bill greenish yellow at base, the culmen of a dark olive-brown tint; iris golden yellow.'
"Considerable variation in the tint of the cinnamon plumage of this species is observable in a series, and specimens from more southern localities are decidedly the darker and richer in color." (Sharpe.)
Very similar to Ixobrychus but the lower part of tibia unfeathered and the quills and tail-feathers blackish.