12 
C AN V ASS-BACK DUCK. 
perfectly ascertained, it would prove that this species, unlike most other 
Ducks, instead of removing farther southward in autumn and winter, takes 
what may be called a lateral march toward our Eastern Districts, in which it 
remains until the weather has become too cold for its constitution, when it is 
forced a second time to migrate, and betake itself to warmer parts of the 
country, where it continues during the rest of the winter. 
The flight of this species, although resembling that of our larger Sea- 
ducks in having the appearance of being rather laboured, is strong, rapid, at 
times very elevated, and well sustained. It swims deeply, especially when 
under apprehension of danger, and this probably the better to enable it to 
escape by diving, at which it is almost as expert as our sea or diving Ducks. 
But although its speed on the water is considerable, it moves rather heavily 
on land. Its food varies, according to the season and locality. The plant 
named Valisneria. on which it is said to feed when on the head waters of 
the Chesapeake, is not found equally abundant in other parts, and even there 
is at times so reduced in quantity, that this duck and several other species 
which are equally fond of it, are obliged to have recourse to fishes, tadpoles, 
water-lizards, leeches, snails, a.nd mollusca, as well as such seeds as they can 
meet with ; all which have been in greater or less quantity found in their 
stomach. 
Nothing is known of its manners during the breeding season ; and we are 
equally ignorant of the changes of plumage which, like other species, it may 
undergo at that period. 
As I have not had very good opportunities of making myself acquainted 
with the modes in which the Canvass-backs are obtained for the markets, I 
here present an account of duck-shooting on the waters of the Chesapeake, 
published some years ago in the “ Cabinet of Natural History,” and of 
which a copy has been transmitted to me by its author, Dr. J. J. Sharpless, 
of Philadelphia, to whom, for this and other marks of attention, I offer my 
best thanks. 
“ The Chesapeake Bay, with its tributary streams, has, from its discovery, 
been known as the greatest resort of water-fowl in the United States. This 
has depended on the profusion of their food, which is accessible on the 
immense flats or shoals that are found near the mouth of the Susquehanna, 
along the entire length of North-East and Elk rivers, and on the shores of 
the bay and connecting streams, as far south as York and James rivers. 
“ The quantity of fowl of late years has been decidedly less than in times 
gone by ; and I have met with persons who have assured me that the number 
has decreased one-half in the last fifteen years. This change has arisen, 
most probably, from the vast increase in their destruction, from the greater 
number of persons who now make a business or pleasure of this sport, as 
