CANVASS-BACK DUCK. 301 



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 clanger, 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, and 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 



