338 FIELD ZOOLOGY. 



that may be found occasionally out of their natural 

 haunts. 



Taking the order as a whole, the diet is vegetable 

 rather than animal; the ducks that are notably flesh- 

 eaters, eat also the sea weeds of the coast regions, and 

 the mergansers on our inland lakes do not despise water 

 plants as a variation of their fish diet. The fresh- water 

 ducks and also the flamingoes eat water plants freely. 

 The bill, in both river and bay ducks, has a series of 

 gutters on either side of the inner surface of the upper 

 mandible, which serve as strainers. Both secure their 

 food by dabbling up from the pond or river bottom 

 small mollusks, crustaceans, and seeds of water plants 

 along with the mud ; and the mud they get rid of by forc- 

 ing it along with the water, out of the mouth through 

 these strainers. Geese are more terrestrial in habits 

 than are the ducks, and often visit land to procure grass, 

 corn, or other grains. Among the ducks, the sexes are 

 usually of quite different plumage; among the geese the 

 differences are less noticeable, while the sexes are alike 

 in the swans. Among the flamingoes, the immature 

 birds are white, while the older birds only have the 

 characteristic plumage. The American red flamingo 

 inhabits Cuba and the Bahamas, and is seen on the 

 Florida Keys rarely. Its adult plumage is scarlet, with 

 the primaries and the secondaries of the wings black. 



The swans have extremely long necks, are more at 

 home on the water than on the land; they inhabit tem- 

 perate regions both in Europe and in the United States, 

 breeding from there northward and wintering from our 

 southern border on south into Mexico. But two sorts 

 are known in the United States, the whistling and the 

 trumpeter swan. The whistler is the smaller of these 



