Of course they, in common with all other Ducks, must take a vast amount of mud and water into their mouths with their food; but instead of having to swallow this, it drains off through the little grooves on the inside edges of the bill, as a ship's deck is drained of water by means of the scuppers.

But that I have explained to you already.

Some Sea Ducks are more plentiful than their river brethren; and as they spend both their days and nights offshore, they run less danger of extermination.

Most of them nest also in the far North, in much the same fashion as River Ducks do.
"Two celebrated members of this group are the Redhead and the Canvasback, who are always welcome guests at dinner, and are so much alike in the crisp brown company dress they wear on the table, with plenty of stuffing and gravy, that very few persons can tell them apart.
But the most famous one of all is the Eider Duck--the one which yields such an abundance of exquisitely soft, warm down that we use it for making the best sort of bedquilts." "Can you always tell a Sea Duck from a River Duck by the feathers--or how ?" asked Rap.
"You can always tell them by their feet," answered the Doctor; "for every Sea Duck has a little flap of skin hanging like an apron from the hind toe, while the hind toe of every River Duck is round and slim, like a Hen's." "I should think there would always be plenty of Sea Ducks," said Rap; "for if they live so far out they ought to be able to take care of themselves and swim or fly away from everybody." "You would think so, my boy, but when man with his many inventions sets out to kill, there is little chance of escape for bird or beast.

Sea Ducks are hunted in their nesting homes, not only for their flesh and eggs, but for the downy feathers with which the nest is lined.