84 NORTH AMERICAN DUCKS, GEESE, AND SWANS. 



the range, while the bulk move south to central Argentina to breed, 

 and retire to northern Argentina to spend the colder portion of the 

 year. The greater part of the species is, therefore, confined to the 

 immediate vicinity of the Rio de La Plata and the lower valleys of its 

 larger branches in a district approximately 700 miles in length north 

 and south, and scarcely half that in width. This same species is 

 found also in southern Africa and southern Asia. 



[Dendrocygna viduata (Linn.). White-faced Tree-duck. 



This species does not come north to the United States, but has occurred as a strag- 

 gler in Cuba (three records) and in Barbados (one flock). Its regular range is from 

 Central Colombia and northeastern South America to Peru, Bolivia, and Paraguay; 

 less common in Argentina, south to Buenos Aires. It seems to perform no regular 

 migration in any part of its range. 



The same species, or one so closely allied that it has not yet been separated, inhab- 

 its much of Africa from ocean to ocean, and from about 15° north latitude (Senegal) 

 to 27° south latitude (Potchefstroom); also the island of Madagascar. Its range in 

 Africa, therefore, is more extensive than in South America, and on the whole is in 

 about the same latitude, for the range in South America extends from latitude 11° 

 N. to latitude 34° S.] 



[Dendrocygna arborea (Linn.). Whistling Duck. 



This ducc is known only from the West Indies, where it ranges from Andros 

 Island, Bahamas, through all the Greater Antilles to St. Croix, Virgin Gorda, and 

 Barbados of the Lesser Antilles; said to be a migrant, but the available data do not 

 suffice to trace its movements.] 



[Dendrocygna discolor (Scl. & Salv.). Southern Red-billed Tree-duck. 



This duck ranges north to the island of Trinidad and to Davila, Panama. It is of 

 wide distribution in northern South America from Colombia to Guiana and south to 

 eastern Peru and northern Brazil. It appears to be resident throughout its range, 

 unless possibly in the extreme northern part, Trinidad, and Panama.] 



DISTRIBUTION AND MIGRATION OF SWANS. 



Olor cygnus (Linn.). Whooping Swan. 



This swan is common in Europe and Asia, and formerly was not 

 rare in Greenland, where it is now nearly exterminated. Single spec- 

 imens of late years have been taken at Atangmik, Godthaab, Ivigtut, 

 and Arsuk in southern Greenland. 



Olor columbianus (Ord). Whistling Swan. 



Breeding range. — The whistling swan breeds principally north of the 

 Arctic Circle, but a few nest on Southampton and Nottingham islands 

 in Hudson Bay, and the species is reported as breeding at Kennedy 

 Lake in Baffin Land. It is fairly common during the breeding season 

 along the Arctic coast in the vicinity of the mouth of the Mackenzie, 

 and not rare throughout much of Alaska. A few pass to the islands 

 of the Arctic Sea, even to latitude 74°. One of the parties of the 



