148 Order Vlll 



their main diet they are sometimes obliged to turn 

 tail upwards as ducks do, but their long necks generally 

 obviate this difficiilty, and they are not accustomed 

 to dive. The diet may be varied by insects and plants 

 which are not aquatic. 



Our three species of Swans are all perfectly white, 

 with black feet, though they di£Eer in size, and are 

 most easily characterized by the biU. The Whooper 

 {Cygnus cygnus), which used to breed in the Orkneys 

 and Greenland, but now only ranges from Iceland to 

 Kamtschatka, chiefly north of the Arctic Circle, has 

 a yellow beak with black tip, the yellow colour ex- 

 tending forward to include the nostrils. The much 

 smaller Bewick's Swan (C. bewicki), a more Arctic and 

 eastern species, which nests north of the Arctic Circle 

 from north Russia to the Lena delta in mid-Asia, 

 has less yellow on the bill, for it does not reach the 

 nostrils. The Mute Swan {C. olor), distinguished by 

 a knob on the forehead, is not a native of England, 

 though many pairs breed on our waters and not un- 

 commordy act as if perfectly wild later in the year. 

 It ranges from Denmark and south Sweden through 

 north Germany to Greece, Tiirkestan and even Mon- 

 golia, and resembles its congeners in its southward 

 winter migration. All three species build huge nests of 

 green plants, grass, and so forth, which are sometimes 

 hidden, but more often quite open to view; the half- 

 dozen or more eggs are very large and white in colour 

 with a yellowish, or in the Mute Swan a greenish tinge. 

 The voices differ considerably, but are, in the wild 

 state, loud and trumpet-like ; tame birds are naturally 

 less vociferous. 



Unlike Geese and Swans, Ducks vary extremely 



