The Mallard, best known of our ducks, is the ancestor of several domestic strains of water-fowl. It is usually found in flocks along the shallow margins of streams, where it procures its food by nibbling along the bottom while its tail protrudes from the water.
The white tail and red feet of the male, which contrast with the gray of the back and wings, are good field-marks as the flock hurriedly rises and makes away.
BLACK DUCK
Anas rubripes tristis Brewster
Other Names.—Black Mallard; Dusky Mallard.
Description.—Sexes similar; general appearance dark brown, darkest on top of head and on back, all feathers margined with brownish buff; cheeks buffy, streaked with black; speculum rich violet, bordered with black, and, at tips of feathers, with white; under-wing plumage white; bill greenish; feet dusky in Black Duck; bright red in the Red-legged Black Duck. Length: 22 inches.
Range in Pennsylvania.—A fairly common migrant from March 1 to May 10 and from October 1 to December 25; uncommon and local as a summer resident, chiefly near lakes or quiet stretches in streams. Nest and eggs like those of the Mallard.
Black Duck, Male
Two forms of the Black Duck occur in Pennsylvania: The smaller, duller Black Duck as a migrant occurs at about the same time as the Mallard and nests locally. The Red-legged Black Duck (Anas rubripes rubripes), a summer bird of Labrador, comes south later in the fall, and has been known even to occur in the northern part of the State in late December, so there is a probability that this form occasionally winters when the water is free of ice.
Both the Mallard and Black Duck quack loudly, like domestic ducks, particularly when they are surprised. Large, dark-colored ducks which show white under the wings as they fly off are likely to be Black Ducks.
GADWALL
Chaulelasmus streperus (Linnæus)
Other Name.—Gray Duck.
Description.—Smaller than Mallard. Male: Top of head with low, fluffy crest, mottled with rufous and black; sides of head and neck buffy, streaked and spotted with black; breast and lower neck black, each feather with a central spot and border of white which gives a remarkably beautiful scaled appearance; back gray-brown; rump and upper and under tail-coverts black; breast and belly whitish; sides finely barred with blackish, lesser wing-coverts chestnut; speculum white; feet yellow. Female: Similar but duller, and with chest and sides buffy, thickly spotted with blackish; underparts white, more or less spotted with black, and with little or no chestnut on the lesser wing-coverts. Length: 20 inches.
Range in Pennsylvania.—A rare and irregular migrant from about March 10 to April 30 and from September 25 to October 30. This is one of our rarer ducks.