RICHARDSON'S PIGEON HAWK 167 



Anderson, R. M., Birds of Iowa, p. 256, 1907. 



Woodruff, F. M., The Birds of the Chicago Area, p. 99, 1907. 



Bruner, L., Wolcott, R. H., Swenk, M. H., A Preliminary Review of the 



Birds of Nebraska, p. 53, 1909. 



Cory, C. B., Birds of Illinois and Wisconsin, p. 479, 1909. 

 A. O. U. Check-List, p. 165, 1910. 

 Bunker, C. D., The Birds of Kansas, p. 147, 1913. 



20A. FALCO COLUMBARIUS RICHARDSONI Ridgway. 357b. 

 Richardson's Pigeon Hawk. 



Field Characters. Not distinguishable at a distance from the 

 Pigeon Hawk, of which it is a variety. 



Description. Slightly lighter in color than the preceding species ; 

 tail crossed by six light and five dark bars. 



Measurements. Same as in the Pigeon Hawk. 



Range. Eastern margin of the Plains Region and westward; 

 straggling to Missouri, Iowa and Wisconsin. 



This light variety of the Pigeon Hawk needs no lengthy treatment 

 in this connection. 



Dr. A. K. Fisher says, "It is with the greatest hesitation that the 

 writer treats of it separately, especially as intermediate specimens 

 are at hand." 



R. M. Anderson says, "There are only a few casual records from 

 Iowa." 



Professor C. C. Nutting in the Proceedings of the Iowa Academy 

 of Science for 1892, page 41, makes mention of a specimen from 

 Storm Lake, Buena Vista county, collected by Mr. Frank Bond, and 

 now in the University Museum. 



The food in so far as determined is similar to that of the Pigeon 

 Hawk, and there is no notable variation from that species in its 

 nesting habits. 



Falco columbarius richardsoni Ridgway. 



*G. D., H. E., and Morton Peck in W. W. Cooke's report on the Bird 

 Migration in the Mississippi Valley, 1884-85: U. S. Department of 

 Agriculture, Division of Economic Ornithology, Bull. 2, p. 119, 1888. 

 (La Porte City.) 



Ridgway, R., Ornithology of Illinois, p. 434, 1889. 



Goss, N. S., History of the Birds of Kansas, p. 286, 1891. 



Hatch, Dr. P. L., Birds of Minnesota, p. 201, 1892. 



