(Plate XIX.) 
THE CANVAS-BACK DUCK. 
F (JLIUULA VALLISNERTA (Wils.), Steph. 
This prince of our Ducks, the superiority oi whose flesh is 
admitted bv all epicures, wanders in its spring and autumn migra¬ 
tions over the whole of North America-. Its breeding home is 
mainly in the most northern districts of British America, but 
many pause in the great marshes and lake districts of the elevated 
portion of the West, even as far south as Montana. Dr. Cones 
saw voting in July on Turtle Mountains, ami Dr. Newberry says 
they were the most numerous of all the summer ducks on the 
lakes and rivers of the Cascade Mountains in Northern Cali¬ 
fornia, where they lay their eggs and rear their young. 
The Canvas-backs begin to come southward about the first of 
November, and spread over the whole of our middle southern 
districts. Their migration does not seem to be performed along 
the coast, but is conducted chiefly by way of the inland waiter- 
courses. A few pause at the Great South Bay and elsewhere in 
Eastern Long Island : more reside through the winter on the 
half-submerged flats of Eastern New jersey ; while the main body 
continues its flight southward to the numerous rivers belonging 
to and in the neighborhood of the Chesapeake Bay, particularly 
the Susquehanna, the Patapsco, Potomac, and James Rivers, 
which appear to be their general winter rendezvous. 
No one knew 1 these birds better, or more thoroughly narrated 
their habits, than Wilson, and he may be quoted liberally w ithout 
hesitation. “ At the Susquehanna,'' he says, “ they are called 
Canvas-backs; on the Potomac, White-backs; and on James 
River, Sheldrakes. They are seldom found at a great distance 
up any of these rivers, or even in the salt-water bay. but in that 
particular part of tide-water where a certain grass-like plant grows, 
on the roots of which they feed. This plant, which is said to be a 
species of Vallisncrla,' grows on fresh-water shoals of from seven 
to nine feet (but never where these arc occasionally dry), in long, 
narrow, grass-like blades, of four or five feet in length ; the root 
is white, and has some resemblance to small celery. This grass 
is in many places so thick that a boat can with difficulty be rowed 
through it, it so impedes the oars, The shores are lined with 
large quantities of it, torn up by the ducks, and drifted up by the 
winds, lying, like hay, in windrows. Wherever this plant growls 
in abundance, the Canvas-backs may be expected, cither to pay 
occasional visits, or to make it their regular residence during the 
1 The- Tap,; nr foigrass of flush wak-r. smael.aica r.illeil Wild pstept, which must not be confounded 
with the Eidt-watur plant u£ the same flame {Zcstcra marina ) 
winter, . . . while, in waters unprovided with this nutritive plant, 
they are altogether unknown. 
" On the first arrival of these birds in the Susquehanna, near 
Idavre-de-Grace, they are generally lean ; but such is the abun¬ 
dance of their favonte food, that, towards the beginning oi 
November, they arc in prettv good order, They are excellent 
divers, and swim with great speed and agility. They sometimes 
assemble in such multitudes as to cover several acres of the river, 
and, when they rise suddenly, produce a noise resembling thunder. 
They float about these shoals, diving, and tearing up the grass by 
the roots, which is the only part they eat They are extremely 
shy, and can rarely be approached, unless by stratagem. W hen 
wounded in the wing, they dive to such prodigious distances, and 
with such rapidity, continuing it so perseveringly. and with such 
cunning and active vigor, as almost always to render the pursuit 
hopeless. From the great demand for these ducks, and the high 
price they uniformly bring in market, various modes are practiced 
to get within gunshot of them. When the winter sets in severely, 
and the river is frozen, the Canvas-backs retreat to its confluence 
with the bay ; occasionally frequenting air-holes in the ice, wdiich 
are sometimes made for the purpose, immediately over their favor¬ 
ite grass, to entice them within gunshot ot the hut or bush, which 
is usually fixed at a proper distance, and where the gunner lies 
concealed, ready to take advantage of their distress " 
The difficulty experienced by some persons in discriminating 
between the Canvas-back and the Red-head, which causes mis¬ 
takes in the market profitable to the gunners and vexatious to 
customers, is unnecessary, at least in the case of the males. “In 
the Red-head, the whole head is clear chestnut-red, with coppery 
or bronzy reflections, and the bill is clear pale grayish-blue, with a 
dark tip. In the Canvas-back, nearly all the head is obscured 
with blackish-brown, and the bill is dusky throughout. There is 
also a marked difference in the shape of the head and bill ; in the 
Red-head, the head is puffy and globose, sloping abruptly down 
to the base of the bill ; in the Canvas-back, the head is longer and 
narrower, and slopes gradually down to the bill, which rises high 
on the forehead. These distinctions ol-form hold with the fe¬ 
males, though less evident in that sex. In the Cairvas-back, more¬ 
over, the back has much more light than dark color, instead of an 
equal amount or less, the fine black lines being very narrow and 
mostly broken up into minute dots." 
