12 A NATURAL HISTORY OF THE DUCKS 



South Africa, Australia, and New Zealand are remarkable for the magnificent 

 sheldrakes of the genera Tadorna and Casarca, and, true to its reputation for ancient 

 or specialized types, Australia supports the most peculiar and aberrant members of 

 the duck tribe — the flightless duck of Auckland Island, the Musk Duck, the Blue 

 Mountain Duck, and the Pink-eared and Freckled Ducks. South Africa, on the 

 other hand, contains no very peculiar types. 



Looking at the duck family from the standpoint of far northern ranges, we find 

 the Eiders and their near relatives characteristic of the arctic regions the world 

 around. The Old-squaw and the King Eider are the two species which extend the 

 farthest north, and the whole family of Eiders are all far northern breeders, while 

 even their winter distribution is chiefly arctic, or at least well beyond that of most 

 other species. The holarctic Ducks and Teal of the Northern Hemisphere once bred 

 in larger numbers over the southern part of their present ranges, but settlement and 

 drainage has greatly affected them in both western Europe and the United States. 

 They naturally tend, however, to breed well south of the arctic salt-water ducks, 

 while some of them — the Spoonbills, Blue-winged Teals, Ruddy Ducks, etc. — can 

 breed even in the south temperate or tropical regions. The true diving ducks, the 

 Pochards and Scaups, occupy an intermediate breeding range, and are not charac- 

 teristic of arctic areas. 



True sea ducks, like the Scoters and Eiders, are not found in the Southern Hem- 

 isphere and range only about as far south in winter as latitude 35° in North America 

 and 42° in Europe. 



The typical ducks of the tropics are the Tree Ducks, which are found all around 

 the world. Two species, the White-faced and the Fulvous, are remarkable for their 

 distribution, which includes both Africa and South America, and in the case of the 

 latter even India and Burma. The members of this genus are typically sedentary, 

 but real migrations do occur at the limits of their ranges, while the coming of the 

 rains gives rise to many local movements which are too intricate to be easily fol- 

 lowed. 



Wide-ranging Species. Such cosmopolitan species as the Pintail, Mallard, 

 Shoveller, and Gadwall extend around the world in the Northern Hemisphere, and 

 vary either not at all or in a very minor degree, giving rise to races such as the 

 Greenland Mallard and the American Pintail. Among the sea ducks, the Long-tailed 

 (Harelda glacialis) is the most abundant, and is another good example of a holarctic 

 bird. 



Confined, or Insular, Species. The best example is the Laysan Teal, whose sole 

 habitat is a small pond on Laysan Isle in the mid-Pacific Ocean. After the Japanese 

 bird raids in 1909, this species was reduced to twelve or thirteen individuals. An- 



