110 THE RAPTORIAL BIRDS OF IOWA 



*Buteo borealis kriderii Hoopes. Ridgway, Robert, A Manual to North. 

 American Birds, p. 232, 1887. 



*Buteo borealis kriderii Hoopes. Cooke, W. W., Report on the Bird Mi- 

 gration in the Mississippi Valley, 1884-1885: U. S. Department of Ag- 

 riculture, Division of Economic Ornithology, Bull 2, p. 115, 1888. 



*Buteo borealis kriderii Hoopes. Goss, N. S., History of the Birds of Kan- 

 sas, p. 261, 1891. 



'Buteo borealis kriderii. Balliet, Letson, Buteo borealis and Other Hawks: 

 The Wisconsin Naturalist, Vol. 1, No. 7, p. 109, 1891. (Des Moines.) 



*Buteo borealis kriderii Hoopes. Bendire, Capt. Chas., Life History of the 

 Birds of North America, Vol. 1, pp. 212, 213, 1892. 



*Buteo borealis kriderii Hoopes. A. O. U. Check List, 2d Edition, p. 130, 

 1895. 



*Buteo borealis kriderii Hoopes. Ridgway, Robert, A Manual to North 

 American Birds, 3d Edition, p. 231, 1896. 



Buteo borealis kriderii. Anderson, R. M., Birds of Winnebago and Han- 

 cock Counties, Iowa, p. 7, 1897. 



Buteo borealis kriderii. Bailey, B. H., Two Hundred Wild Birds of Iowa, 

 p. 62, 1906. 



Buteo borealis kriderii. Keyes, Charles Reuben, The lowan Raptores: 

 The Iowa Ornithologist Vol. 3, No. 1, p. 1897. 



Buteo borealis kriderii. Anderson, R. M., Nesting Habit of Krider's Hawk: 

 The Iowa Ornithologist, Vol. 3, No. 3, pp. 31, July, 1897. (Winnebago 

 and Hancock Counties.) 



Buteo borealis kriderii Hoopes. Widmann, Otto, A Preliminary Catalog 

 of the Birds of Missouri: Trans. Acad. Sci. of St. Louis, 1907, pp. 95-96. 



Buteo borealis krideri Hoopes. Bruner, L., Wolcott, R. H., Swenk, M. H., 

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



Buteo borealis krideri (Hoopes). Bunker, C. D., The Birds of Kansas, p. 

 147, 1913. 



9B. BUTEO BOREALIS CALURUS Cassin. 337b. 

 Western Red-tail. 



Field Characters. Dark colored Red-tailed hawks showing much 

 red and rusty whitish beneath. Darker but otherwise like the East- 

 ern Red-tail. 



Description. Above showing very little light color, sometimes 

 sooty ; the white of the Eastern Red- tail replaced by buffy, rusty, or 

 dusky shades. Legs with rufous barring and tail having usually sev- 

 eral more or less distinct black bars on the red background. Inter- 

 grading specimens are common. 



Measurements. About as in the Eastern Red-tail. 



