Adult Male in Summer. Plate CCLV. Fig. 1.
Bill scarcely longer than the head, straight, slender, nearly cylindrical, towards the end broader and flattened, the tip narrow. Upper mandible with the dorsal line straight, excepting at the end, where it is a little curved, the ridge convex, flattened at the broad part, the sides slightly sloping, the edges rounded, and near the slightly curved obtuse tip inflected. Nasal groove linear, extending to near the tip; nostrils basal, linear-elliptical. Lower mandible with the angle very long and narrow, the sides convex, the tip narrowed, obtuse.
Head small, with the fore part high and rounded; eyes small. Neck of moderate length. Body rather full. Feet rather short, slender; tibia bare a short way above the joint; tarsus much compressed, narrowed before and behind, covered anteriorly with numerous scutella; toes very slender, first extremely small, free, with a slight membrane beneath, second shorter than third, which is a little longer; all scutellate above, the anterior margined on both sides with lobed and pectinated membranes, which are united at the base, so as to render the foot nearly half-webbed, the outer web much longer than the inner. Claws very small, compressed, arched, obtuse, that of the middle toe with an inner sharp edge.
Plumage soft and slender, the feathers on the back and wings somewhat distinct. Wings long and pointed; primary quills tapering, but rounded, the first longest, the second a little shorter, the rest rapidly graduated; secondary quills rather short, obliquely truncate, the inner tapering and elongated, so as nearly to equal the longest primaries when the wing is closed. Tail of moderate length, much rounded, of twelve feathers.
Bill greenish-yellow, black at the point. Iris brown. Feet pale greyish-blue. Upper part of the head black; loral space and chin blackish-grey; sides of the head, and a band round the occiput, white. Sides and fore part of the neck, breast, abdomen, and lower tail-coverts deep orange-red. Fore part of the back, scapulars, and inner secondaries, black, the feathers edged with whitish; wing-coverts deep ash-grey; quills dark greyish-brown, their shafts and basal parts white; the ends of the secondary and primary coverts, and the basal part of the outer webs of the primaries, being white, a band of that colour is seen on the wing when it is extended. Upper tail-coverts orange-red; tail deep grey, darker towards the end, slightly tipped with reddish.
Length to end of tail 7 1/2 inches, to end of claws 6 3/4; extent of wings 13; wing from flexure 5; tail 2 3/4; bill along the back 11/12, along the edge of lower mandible 1 1/12; tarsus 10/12; middle toe 10/12, its claw 1 1/2/12.
Adult Female in summer. Plate CCLV. Fig. 2.
The Female has the upper part variegated with light red and brownish-black, the central part of each feather being of the latter colour, the upper tail-coverts entirely of the former. Wings greyish-black, with a transverse white band; tail deep grey as in the male. The lower parts are of a less pure red than those of the male, being paler and tinged with grey.
Adult in winter. Plate CCLV. Fig. 3.
The winter plumage of the adult is very different in colour. The bill is nearly black, the feet as in summer. The upper part of the head, cheeks, fore part and sides of the neck, breast, abdomen, lower and upper tail-coverts, and a band across the wing, are white; a brownish-black line from the eye to the occiput, which is of the same colour, as well as the middle of the hind neck. The back, scapulars, and inner secondaries, are ash-grey, the wings as in summer.