112 



THE RAPTORIAL BIRDS OF IOWA 



Buteo borealis calurus. Widmann, Otto, A Preliminary Catalogue of the 

 Birds of Missouri: Trans. Acad. Sci. of St. Louis, p. 96, 1907. 



Buteo borealis calurus (Cassin). Bruner, L., Wolcott, R. H., Swen>k, M. H., 

 A Preliminary Review of the Birds of Nebraska, p. 51, 1909. 



Buteo borealis calurus (Cass.). Bunker, C. D., The Birds of Kansas, p. 

 147, 1913. 



Fig. 40. Harlan's Hawk, or Black Red-tail. 



9C. BUTEO BOREALIS HARLANI (Audubon). 337d. 

 Harlan's Hawk. Black Red-tail. 



Field Characters. A large blackish hawk without a red tail, and 

 to be distinguished by no other special characters. More likely to be 

 confused with dark forms of the Rough-legged Hawk than with any 

 others. 



Description. Above, dusky or sooty, the tail mottled with black, 

 whitish, and some red. Below, whitish to dusky or sooty, in lighter 

 forms the lower breast showing more or less of a dark belt. Imma- 

 ture birds with barred tails. 



