ORDER V. DUCKS, GEESE, AND SWANS. 



ANSERES. 



Family 1. DUCKS, GEESE, and SWANS. ANATID*. 49 

 species, 6 subspecies. 



The Anatidae of North America are placed in five well-marked sub- 

 families, the Mergansers (Mergince] , River Ducks (Anatintz), Sea Ducks 

 {Fuligulina:) i Geese (An$eriiuz) t and Swans (Cygnina). 



The Mergansers, Saw-bills, or Shelldrakes are fish-eating Ducks and 

 their rounded bills, set with toothlike projections along the sides, are 

 of evident use to them in holding their prey. 



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 fre- 

 quent 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 im- 

 mersing 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 in- 

 creased. 



In spite of their comparatively short wings the large muscles attach- 

 ed to them give to the Anatidae 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 there- 

 fore unable to fly. During this comparatively helpless period the' 

 brightly colored males assume in part the plumage of the females and 



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