DUCKER—DULWILLY 171 



white, though as long as their reproductive power lasts they 

 "breed true." The amount of variation in domestic Ducks, how- 

 ever, is not comparable to that found among Pigeons, no doubt 

 from the absence of the competition which Pigeon-fanciers have so 

 long exercised. One of the most curious effects of domestication in 

 the Duck, however, is, that Avhereas the wild Mallard is not only 

 strictly monogamous, but, as Waterton believed, a most faithful 

 husband — remaining paired for life, the civilized Drake is notori- 

 ously i3olygamous. 



Very nearly allied to the common Wild Duck are a consider- 

 able number of species found in various parts of the world in 

 which there is little difference of plumage between the sexes — both 

 being of a dusky hue — such as Anas obscura of North America, A. 

 superciliosa of Australia, A. poicUorhyncha of India, A. mcllcri of 

 Madagascar, A. xantkorhyncha of South Africa, and some others. 



It would he impossible here to enter upon the other genera of 

 Anatinse. AVe must content ourselves by saying that both in 

 Eui'ope and in North America there are the groups represented 

 by the Shovfxer, Garganey, Gadwall, Teal, Pintail, and 

 WiGEON — each of which, according to some systematists, is the 

 type of a distinct genus. Then there is the group ^-Ex with its 

 beautiful representatives the Wood-Duck {^E. sjMnsa) in America 

 and the Mandarin-Duck (^-E. galericulata) in Eastern Asia. Besides 

 there are the Sheld-drakes (Tadorna), confined to the Old World,^ 

 and remarkably developed in the Australian Kegion ; the Musk- 

 Duck (Cairina) of South America, which is often domesticated, and 



^x SPONSA. Dendrocygna. 



(After Swainson.) 



in that condition will produce fertile hybrids Avith the common 

 Duck ; and finally the Tree-Ducks {Dendrocygna), which are almost 

 limited to the Tropics. 



DUCKER, see Doucker. 



DULWILLY, said to be a local name of the Ringed Plover, 

 jEgialitis hiaticola ; and, according to Prof. Skeat, signifying dull 

 of will or stupid, though the application of such a name is not 

 obvious. (See, however, Dotterel.) 



^ To these belong apparently the genera Chcnalopcx and Plectropterus, though 

 from their size the species of each beai-s in English the name of Goose. 



