Canvas-Back (aythya Vallisneria), a duck of the family fuligulince, or sea ducks, peculiar to North America, and celebrated as the most delicious of all water fowl. The sea and its bays and estuaries are the principal haunts of this genus. Sir John Richardson states that the A. Vallisneria, the canvas-back, A. Americana, the red-head, and fulix collaris, the ring-neck, breed in all parts of the fur countries, from the 50th parallel to their most northern limits, and associate much on the. water with the anatina, or river ducks. The male canvas-back has the region of the bill, the top of the head, chin, base of the neck, and adjoining parts dusky red; sides of the head and whole length of the neck deep chestnut red; lower neck, fore part of breast and back, pitch black; the rest of the back white, closely marked with fine undulating lines of black; rump and upper tail coverts blackish; wing coverts gray, speckled with blackish; primaries and secondaries light slate color. Tail short, the feathers pointed; lower part of the breast and abdomen white; flanks the same color, finely pencilled with dusky; lower tail coverts blackish brown, intertwined with white. Length 22 inches, wing 9 1/2 inches. The bill is bluish black; the feet and"legs are dark slate color, the irides fiery red.

The female is somewhat smaller, and is less brilliantly and less distinctly colored than the male. The canvas-back duck returns from its breeding places at the north about the first of November, and during the winter extends its visits to the southern parts of the seacoast of the United States. It is not unfrequently shot in the eastern part of the Great South bay of Long Island, in Long Island sound, on the shores and bays of New Jersey, and in the estuary of the Delaware; but in these localities it is but a common duck, nowise superior to many others, and decidedly inferior to the redhead. It is only in the Chesapeake bay, about the mouths of the Potomac river and Gunpowder creek, that it becomes superior to all other wild fowl. This excellence is attributable solely to the peculiar food which it finds in that estuary, a plant commonly known as wild celery, botanically as the zostera Vallisneria, or ValUsneria Americana, which must not be confounded with the zostera marina, or common eel grass. This plant, of which the canvas-back duck is so fond that it derives from it its specific name of Vallisneria, grows on shoals, where the water is from 8 to 9 ft. in depth, which are never wholly bare.

It has long, narrow, grass-like blades, and a white root somewhat resembling small celery, whence it has its vulgar name, though it has no connection whatever with that plant. This grass is in some places so thick as materially to impede a boat when rowed through it. It is on the root alone that the canvas-back feeds. For these roots the canvas-backs dive assiduously and continually, tearing up the grass, and strewing it on the surface of the water in long, regular rows. The duck rises to the surface as soon as he has obtained his favorite root, which he cannot swallow under water; and, before he has got his eyes well open, says Wilson, is often robbed of his meal by the widgeons or bald-pates (mareca Americana), which never dive, but, being equally fond of the root of the Vallisneria, depend on their adroitness and agility to rob the industrious canvas-backs. On this account the bald-pates congregate eagerly, as far as they are allowed to do so, with the canvas-backs; who, however, live in a constant state of contention with their thievish neighbors, and, being by far the heavier and more powerful fowl, easily beat off the widgeons, who are compelled to retreat, and make their approaches only by stealth at convenient opportunities.

With the canvas-backs also associate the red-heads, the scaups, or, as they are called in the Chesapeake, the black-heads, and some other varieties, with which they feed on terms of amity. - The excellence of the flesh of the canvas-backs causes them to be much sought after for the market, but in the waters -which they frequent they are so strictly preserved by the real sportsmen, who abound in that part of the country, and have obtained the control of most of the shores, that the worst methods of poaching are prohibited. The canvas-backs will not fly, like geese and many species of ducks, to decoys; and the anchoring of batteries on the feeding flats, and the sailing after the birds on their grounds with boats, are not permitted under any circumstances, which has preserved thus far this delicious fowl from extermination. The ordinary mode of killing them is by shooting them on the wing, from behind screens, or blinds, as they are termed, of reeds, arranged on the projecting points of land, over or in the vicinity of which the fowl are compelled to fly in going up and coming down the bay, to and from their feeding grounds.

The velocity at which they fly, as well as the height of their course, renders it extremely hard to hit them; and a great allowance must be made in taking aim, in order not to shoot far behind the object, which will surely be the case if the sight of the gun be directly laid on the passing fowl. Add to this, that the feathers on the breast of this duck, as of many others of the family, are so closely compacted together, of so thick and elastic texture, and so matted by the aid of the oil from the gland in the rump with which the bird lubricates them, that any ordinary shot, striking on the breast as the fowl comes toward the shooter, will make no impression. The best and most deliberate fowlers, therefore, when they have time to do so, let the flights pass, and then shoot them with the grain of the feathers. A remarkable propensity of these birds is to be attracted by the appearance of any unusual sight on the shores; and anything of this nature will induce them to leave their feeding grounds, and swim in great flocks of thousands together, perfectly fearless, or rather reckless, to the places where men lie in ambush for them.

It is said that the scaup or black-head can be allured in this manner more easily than the canvas-back; and that the red-heads and widgeons, when they are alone, cannot be deceived at all, though when in company with others they will fall into the same error, and accompany the flocks to their own destruction. Advantage has been taken of this habit to ensnare the unwary birds by a system which is called toling. It is thus practised: A long range of screens is set up along the shore, within a few yards of the water mark, behind which the shooters lie concealed, with small openings at intervals to permit the egress and ingress of a small cur-dog, the more like a fox the better, as also the odder his appearance and the more remarkable his color, who is taught to run back and forward in front of the blinds, performing all sorts of curious tricks and antics, to attract the attention of the fowl. So soon as this object is attained, they will swim up in a body within easy gunshot; and so totally are they demented by their curiosity, that so long as the shooter holds himself concealed, and the dog continues his deceptive gambols, so long can the stupid birds be drawn up, to receive volley after volley, until they are decimated or destroyed, perfectly regardless of their dead or wounded companions, through which they will continue to advance to the muzzles of the guns.

The only thing necessary to be observed in this sort of shooting is not to overshoot the flock, which a novice is sure to do, so deceptive is the effect of shooting over water. The plan adopted by the oldest shooters is, in taking aim, to see the whole body of the nearest fowl, in a flock of hundreds, in clear relief above the sight of the gun, and then the charge will fall into the middle of the throng. By good sportsmen, toling, and indeed any other way of shooting canvas-backs than on the wing, from points, is held to be rank poaching. When the rivers begin to freeze, vast numbers of all these varieties of ducks congregate at the open air holes, and fearful slaughter is made of them in hard weather at such places; as many, it is said, as 88 canvas-backs having been killed at a single discharge of a heavy gun. Wounded canvas-backs are expert divers, and are extremely difficult to recover; wherefore it is usual to be accompanied by a good Newfoundland retriever.