GAUWALL. 27 



[Anas aberti Ridgw. Abert Duck. 

 A species known only from the type specimen taken at Mazatlan, INIexico.] 



Chaulelasmus streperus (Linn.). Gadwall. 



Breedmg range. — A large majority of the North American individ- 

 uals of this species breed in the prairie district extending- from Mani- 

 toba to the Rocky Mountains, south to western Minnesota, and from 

 northern South Dakota north to the Saskatchewan. 



The species breeds connnonly from the Rocky Mountains to the 

 Pacific, south to southern Colorado, Utah, Nevada, and in nearly the 

 whole of California; also probably in the Mogollon Mountains of 

 Arizona. The northern range extends to southern British Columbia, 

 Alberta (rarely or casually to Lesser Slave Lake), and to Fort Churchill 

 on Hudson Bay. There is no authentic record for the Mackenzie 

 Valley, and if the specimen in the British Museum labeled "Bering 

 Straits" really was captured there it was a wanderer, as was also one 

 taken at Unalaska, March 18, 1879. 



In the Mississippi Valley the gadwall occasionall}' breeds in northern 

 Nebraska and rarely in Kansas. Formerlv it bred in "\^'isconsin(IIori- 

 con Marsh and Lake Koshkonong), there is one record for Ontario 

 (St. Clair Flats), and one for Anticosti Island. It is only a straggler 

 to New England and the Maritime Provinces north to Quebec and 

 Newfoundland, and east of the Mississippi is rare north of North 

 Carolina. 



The gadwall is a common breeder in Europe and Asia, ranging south 

 in winter far into Africa and to southern Asia. 



Winter range. — The principal winter home of the gadwall is in the 

 lower Mississippi Valle}^, especialU' Texas, Louisiana, and Arkansas. 

 It rarelj" winters as far north as Illinois, but is more common to the 

 eastward in North Carolina and Florida; accidental in Cuba (twice), 

 Jamaica, and the Bermudas. The winter range extends to the south- 

 ern end of Lower California, to Mazatlan, and the City of Mexico. In 

 northern Mexico the species is common through the winter, and birds 

 have been found paired in May, the late date indicating that they 

 intended to remain and breed. Thence it extends commonly to Utah 

 and Oregon, rarely to Washington and British Columbia. 



Sj/rmg migration. — Only a few notes on the migration of this 

 species have been recorded. The average date when the first spring 

 migrants reach southern Iowa is March 18 (earliest March 10, 1896), 

 it thus being one of the earlier ducks in this part of its range. It 

 reached Heron Lake, Minn., April 1 (earliest March 17, 188()); Love- 

 land, Colo., March 6, and Terry, Mont., about April 1. The first 

 migrant was seen at Aweme, Manitoba, April 23, 1898, and at Indian 

 Head, Saskatchewan, April 18, 1892, and April 24, 1901. Eggshave been 

 secured at St. Clair Flats, Ontario, a])out May 30; in western Minne- 



