The Migration of North American Birds 



SECOND SERIES 



VIII. RAVENS 



Compiled by Harry C. Oberholser, Chiefly from Data in the Biological Survey 



AMERICAN RAVEN 



Some form of the common American Raven occupies nearly all of North 

 America and Mexico. As a species it is chiefly resident, though during autumn 

 and winter it wanders about more or less, especially in the United States; 

 yet it does not pass much to the south of its breeding range, and its movements 

 are not sufficient to constitute a regular migration. From the extreme northern 

 section of its range it withdraws in part during the coldest weather, yet even 

 as far north as Banks Land, Canada, it sometimes remains all through the 

 long Arctic winter night. It is apparently local while nesting, and there are 

 large areas within the limits of its breeding range where it scarcely ever appears 

 at this season; in fact, it is rare at any time throughout the eastern half of 

 the United States. The following four subspecies of the Raven are now known 

 from North America. To correlate these with the A. O. U. Check-List, com- 

 bine the first two for the American Raven, and the last two for the Northern 

 Raven. 



The American Raven (Corvus corax sinuatus) inhabits middle western 

 North America and breeds north to southwestern Mackenzie; west to British 

 Columbia, northeastern Washington, western Wyoming, southwestern New 

 Mexico, southwestern Arizona, and Tepic, Mex.; south to northern Honduras; 

 and east to Vera Cruz in Mexico, central Texas, eastern Kansas, and central 

 northern North Dakota. 



At Forestburg, S. D., three years' observation gives an average autumn 

 arrival of September 26, with September 12, 1904, as the earliest date; and 

 at the same place the latest spring record is April 23, 1904. At Aweme, Mani- 

 toba, three years give an average fall arrival of October 17, with an earliest 

 date of October 10, 1898. At Margaret, Manitoba, three years' observation 

 gives September 28 as the average autumn appearance, with September 14, 

 1909, as the earliest date. At the same locality the latest spring record was 

 March 21, 191 2. 



The Clarion Island Raven {Corvus corax clarionensis) breeds in the 

 southwestern United States, north to central northern Oregon; west to western 

 California and western Lower California; south to the Revillagigcdo Islands, 

 Mexico; east to southeastern Arizona, central Idaho, and northeastern Nevada. 



The Northern Raven (Corvus corax principalis) breeds in northern 

 North America, north to northern Cireenland, Banks Land, and the nortliern 

 coast of Alaska; west to the western coast of .\laska, the Aleutian Islands, 



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