Bill and feet dull greenish-brown. Iris brown. The general colour is pale brownish-yellow, mottled with dusky; a whitish ring round the eye; tail with a black band, rump whitish, primary quills dusky, the outer edges of the secondaries whitish.
The young in autumn.
Bill greyish-black; feet bluish-grey. The upper parts brownish-black, spotted with white, some of the spots yellow; the wings and tail as in the adult, but the latter tinged with grey, and having eight dark bars on all the feathers. The fore part and sides of the neck, and the sides of the body, greyish-white, mottled with brownish-grey; axillary feathers brownish-black; the rest of the lower parts white.
Adult in winter. Plate CCCXXXIV. Fig. 3.
The adult in winter has the upper parts light greyish-brown, the margins of the feathers much lighter; the sides and fore parts of the neck pale grey, with dark grey streaks and spots; lower parts white. In other respects the colours are as in summer.
In an adult male of this species, there is a double row of papillæ on the roof of the mouth. The tongue is 1 inch long, slender, tapering, emarginate and papillate at the base, grooved above, horny on the back. The œsophagus a, is 5 inches long, at its upper part 4 twelfths in diameter, enlarged to 1/2 inch on the lower part of the neck. The proventriculus, b, oblong, its greatest diameter 8 twelfths, its glandules oblong and about a twelfth in length. The stomach, c, d, e, f, is a very powerful gizzard of an irregular roundish form, 1 inch 5 twelfths long, 1 inch 3 1/2 twelfths in breadth; its lateral muscles very large and distinct, the right d, 4 twelfths thick, the left, e, 3 twelfths, the tendons large; the epithelium thick, longitudinally rugous, and of a reddish colour. The intestine g, h, i, is 2 feet 2 inches long, its diameter about 2 twelfths; the cœca 2 inches 2 twelfths long, their diameter at the base half a twelfth, toward the end 2 twelfths; the rectum 3 twelfths in diameter, and 2 1/2 inches long.
In the stomach were several shrimps. The lobes of the liver very unequal, the right being 2 1/4 inches in length, the other 1 4/12. No gall-bladder.
The trachea is wide, flattened, membranous, 4 twelfths broad at the upper part, gradually diminishing to 2 twelfths, its rings which are very slender, about 100. The lateral muscles exceedingly thin, but becoming more distinct towards the lower part; the sterno-tracheal slender. Bronchi of moderate length, of about 20 half-rings.