Anas Boschas, Linn. Syst. Nat. vol. i. p. 205.—Lath. Ind. Ornith. vol. ii. p. 850.—Ch. Bonaparte, Synopsis of Birds of the United States, p. 383.
Mallard, Anas Boschas, Wils. Amer. Ornith. vol. viii. p. 112. pl. 70. fig. 7.—Nuttall, Manual, vol. ii. p. 378.
Adult Male. Plate CCXXI. Fig. 1. 1.
Bill about the length of the head, higher than broad at the base, depressed and widened towards the end, rounded at the tip. Upper mandible with the dorsal line sloping and a little concave, the ridge at the base broad and flat, towards the end broadly convex, as are the sides, the edges soft and rather obtuse, the marginal lamellæ transverse, fifty on each side; the unguis oval, curved, abrupt at the end. Nasal groove elliptical, subbasal, filled by the soft membrane of the bill; nostrils subbasal, placed near the ridge, longitudinal, elliptical, pervious. Lower mandible slightly curved upwards, with the angle very long, narrow, and rather pointed, the lamellæ about sixty.
Head of moderate size, oblong, compressed; neck rather long and slender; body full, depressed. Feet short, stout, placed a little behind the centre of the body; legs bare a little above the joint; tarsus short, a little compressed, anteriorly with small scutella, laterally and behind with reticulated angular scales. Hind toe extremely small, with a very narrow membrane; third toe longest, fourth a little shorter, but longer than second; all the toes covered above with numerous oblique scutella; the three anterior connected by reticulated membranes, the outer with a thick margin, the inner with the margin extended into a slightly lobed web. Claws small, arched, compressed, rather acute, that of the middle toe much larger, with a dilated, thin, inner edge.
Plumage dense, soft, and elastic; of the head and neck short, blended, and splendent; of the other parts in general broad and rounded. Wings of moderate length, acute; primaries narrow and tapering, the second longest, the first very little shorter; secondaries broad, curved inwards, the inner elongated and tapering. Tail short, much rounded, of sixteen acute feathers, of which the four central are recurved.
Bill greenish-yellow. Iris dark brown. Feet orange-red. Head and upper part of neck deep green, a ring of white about the middle of the neck; lower part of the neck anteriorly, and fore part of breast, dark brownish-chestnut; fore part of back light yellowish-brown, tinged with grey; the rest of the back brownish-black, the rump black, splendent with green and purplish-blue reflections, as are the recurved tail-feathers. Upper surface of wings greyish-brown, the scapulars lighter except their inner webs, and with the anterior dorsal feathers minutely undulated with brown. The speculum on about ten of the secondaries is of brilliant changing purple and green, edged with velvet-black and white, the anterior bands of black and white being on the secondary coverts. Breast, sides, and abdomen, very pale grey, minutely undulated with darker; lower tail-coverts black with blue reflections.
Length to the end of the tail 24 inches, to the end of the claws 23, to the tips of the wings 22; extent of wings 36; wing from flexure 10 1/2; tail 4 1/4; bill 2 2/12; tarsus 1 3/4; middle toe 2 2/12, its claw 5/12. Weight from 2 1/2 to 3 lb.
Adult Female. Plate CCXXI. Figs. 2. 2.
Bill black in the middle, dull orange at the extremities and along the edges. Iris as in the male, as are the feet. The general colour of the upper parts is pale yellowish-brown, streaked and spotted with dusky brown. The feathers of the head narrowly streaked, of the back with the margin and a central streak yellowish-brown, the rest dark, of the scapulars similar, but with the light streak on the outer web. The wings are nearly as in the male, the speculum similar, but with less green. The lower parts dull ochre, deeper on the lower neck, and spotted with brown.