Color Key to North American Birds / with bibliographical appendix

by Frank M. Chapman

The River Ducks include such well-known species as the Mallard, Black Duck, and Widgeon. They differ from the Bay or Sea Ducks in not having a well-developed web or flap on the hind-toe. As a rule they feed in shallow water by tipping, standing on their heads, as it were, while reaching the bottom for food.

The Bay or Sea Ducks have the hind-toe webbed. They feed, as a rule, in deeper water than the River Ducks, sometimes descending to the bottom in water over one hundred feet deep. During the winter they gather in flocks often of several thousand individuals, and frequent the larger bodies of water.

With both the River and Bay Ducks the sides of the broad, flat bill are set with gutters which serve as strainers, retaining the mollusks, seeds and roots of aquatic plants on which these Ducks feed, while the mud or water taken in with the food is forced out the sides of the bill as it closes.

Geese are more terrestrial than Ducks and often visit the land to nip the grass. This is particularly true in the west where large flocks of, Geese, especially Snow Geese, may be seen feeding on the prairies. On the water they feed over shallows by tipping and probing the bottoms.

Swans also feed from the surface of the water either by simply immersing the head and neck or by half submerging the body, when, with the tail pointed to the zenith, the length of their reach is greatly increased.

In spite of their comparatively short wings the large muscles attached to them give to the Anatidæ great power of flight. Not only do they make extended journeys, when migrating, without a rest, but they attain a speed which is surpassed by but few birds. Some of the smaller species, when alarmed, doubtless flying at the rate of one hundred miles an hour.

In common with other diving water birds the Ducks, when molting, lose most of their wing feathers all at once, and for a time are therefore unable to fly. During this comparatively helpless period the brightly colored males assume in part the plumage of the females and are thereby rendered less conspicuous. With the return of the power of flight, however, they regain their distinctive, male plumage, which is usually brighter than that of the female. With our Geese and Swans there is no sexual difference in color.

Most of our Ducks and Geese breed in the north, some within the Arctic Circle, and winter from the southern limit of frozen water southward. The American Merganser, Hooded Merganser, Wood Duck, Buffle-head, Golden-Eyes, Tree Ducks, and possibly Harlequin Duck nest in hollow trees, at times some distance from the water. The young of the American Golden-eye and of the Wood Duck have been seen to reach the water by jumping from the nest-hole and fluttering down in response to the calls of the parent below. It is said that they are also brought down in the bill of the old bird, but this statement apparently lacks confirmation.

The remaining species of our Ducks, Geese, and Swans, nest as a rule, on the ground generally near water. From five to fifteen and, in the case of the Fulvous Tree Duck, possibly as many as thirty eggs are laid. In color they vary from white to buffy and pale olive and are always uniformly colored. Incubation is performed by the female alone. The males at this period among most Ducks deserting their mate to undergo the partial molt before mentioned. While incubating the females surround their nest with soft down plucked from their bodies and when leaving the nest to feed, this down is drawn over the eggs with the double object, doubtless, of concealing them and of keeping them warm.

With Eider Ducks this down constitutes the larger part of, if not the entire nest. Saunders states that in Iceland the down in each nest weighs about one-sixth of a pound. This is gathered by the natives, who, however, are careful to afford the sitting bird an opportunity to raise her brood without further molestation.