THE WORLD'S BIRDS. 33 



Common Duck or Mallard (Anas boscas), found all 

 round the northern hemisphere in a wild state, 

 and in most countries domesticated. The other 

 domestic duck, the Muscovy, is a common wild 

 bird in the warm parts of America. The wild 

 representative of the Mallard in Australasia is the 

 Grey Duck (Anas super ciliosa), a dark-brown species 

 with the sexes alike and much like the female of 

 the common bird. 



The celebrated Eider-Duck (Somateria mollis- 

 sima) is a northern bird, as are all its allies, and, 

 indeed, most diving ducks. 



The Mandarin Duck of China and Eastern Asia 

 generally (A ex galericulata) is almost as well known 

 by repute on account of the wonderfully diversified 

 plumage of the male, and especially his chestnut 

 ruff and wing-fans ; it is widely kept and often 

 bred in captivity. Its near relative, the Wood- 

 Duck of North America (A. sponsa) is completely 

 domesticated in Europe, and there called the Caro- 

 lina Duck. The Wood-Duck of Australia (Chlamy- 

 dochen jubata), though also a small species, is goose- 

 like in form. These three species are perchers 

 and tree-breeders, as are also the Whistlers or Tree- 

 Ducks (Dendrocycna), long-legged birds of striking 

 but not brilliant colours, which are the charac- 

 teristic ducks of the Tropics. 



The Sheldrakes (Tadorna, Casarca, Chenalopex) 

 are large strikingly-coloured species, with long legs 

 and wings, widely distributed. The New Zealand 

 Sheldrake (Casarca variegata), the only one of this 

 group of ducks with a marked sex-difference, is 

 well known as the Paradise Duck ; the Egyptian 

 Goose (Chenalopex agyptiacus) is well known 

 both in domestication and as a wild bird in Africa. 

 The birds called Sheldrakes in America are really 

 Mergansers (Mergus), saw-billed, fish-eating, diving 



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