Adult Male in Summer. Plate CCCLXV. Fig 1.
Bill short, robust, tapering, somewhat compressed; the upper mandible nearly as large as the lower, its dorsal outline very slightly convex, the sides rounded, the sharp edges inflected, the marginal outline slightly angulate; lower mandible broader, with involute sharp edges. The palate with a prominent knob. Nostrils basal, round, partly concealed by the feathers.
Head of moderate size, ovate; eyes rather small; neck short, body compact. Feet of ordinary length; tarsus compressed, anteriorly covered with seven large scutella, sharp behind; toes of moderate size; the lateral toes equal, the hind toe stout. Claws long, slightly arched, laterally grooved, compressed toward the end, very acute, that of the hind toe much elongated.
Plumage soft and blended, the feathers somewhat distinct on the back and wings. Wing long, pointed; first quill longest, second scarcely shorter; secondaries emarginate. Tail rather long, deeply emarginate.
Bill yellow tipped with dusky; iris hazel; feet and claws black. The head and fore part of the neck are black; a band of white passes from the base of the upper mandible over the eye, becomes broader, and, descending on the neck, margins the black of that part. The lower parts are white, the sides streaked with black. A brownish-red crescent on the hind neck; the feathers of the upper parts black, broadly margined with yellowish-red; the first row of smaller wing-coverts margined with white, the secondary coverts tipped with the same; the primary quills narrowly edged with reddish-white, the secondary with yellowish-red; as are the tail-feathers, of which the two outer have a wedge-shaped white spot at the end.
Length to end of tail 6 3/12 inches; wing from flexure 3 10/12; tail 2 1/12; bill along the ridge 6/12, along the edge of lower mandible 8/12; tarsus 9/12; hind toe 4/12, its claw 7/12; middle toe 7 1/2/12, its claw 4/12.
Male in winter. Plate CCCLXV. Fig. 2.
Bill dull yellow, tipped with dusky; feet and claws black. Upper part of the head black, the feathers edged with brownish-red; the cheeks greyish-brown; the throat, and fore part of the neck, greyish-white, a reddish-white band from the bill, over the eye, and down the side of the neck; the upper parts light brownish-red with black spots. The tips of the first row of small coverts, and of the secondary coverts, white; the quills and coverts blackish-brown, edged with light red; the tail brownish-black, the feathers edged with reddish-grey.
Female in summer. Plate CCCLXV. Fig. 3.
The female has the bill yellowish-brown, tipped with dusky, the feet and claws brownish-black, the upper part of the head, the hind neck, and the back, are reddish-grey, spotted with black; the wings and tail as in the male. A reddish-white band over the eye, and down the neck; the lore dusky; a black band from behind the eye; the cheeks light yellowish-brown; a black band from the lower mandible margining the throat, which is white; as are the lower parts generally; but the lower part of the neck is spotted with black, and the sides streaked with dusky.