258 BULLETIN 5 0, UNITED STATES NATIONAL INIUSEUM 



Natal down. — BiifFy white to pale grayish white. 



Adult male.—Wmg 352-400 (379.5); tail 204-232 (221.3); culmen 

 from cere 23-27.5 (25. G); tarsus 81-90.5 (84.9); middle toe without 

 claw 39.5-45.5 (42.5 mm.) (8 specimens). 



Adult females.— Wm^ 393-432 (413.5); tail 219-248 (237.5) ; culmen 

 from cere 24-30 (26.8) ; tarsus 81.5-94 (87.5) ; middle toe without claw 

 40-49.5 (46.5 mm.) (10 specimens). 



Range. — Breeds from southeastern Manitoba (Oak Lake, Riding 

 Mountains), North Dakota, and western and south-central Minnesota, 

 rarely to extreme western Ontario (Malachi) ; south to Wyoming 

 (Black Hills), eastern Colorado, and to Nebraska. 



Winters from South Dakota and southern Minnesota south through 

 the Great Plains west of the Mississippi as far as Arizona (the San 

 Francisco Mountains); New Mexico (near Espanola), central and 

 eastern Texas, and Louisiana, eastward along the Gulf coast to Missis- 

 sippi. Recorded (uncertainly) from Durango and Zacatecas, Mexico. 



Casual in Wisconsin and Illinois; accidental in South Carolina and 

 Georgia (St. Marys and Sapelo Island). 



Type locality.- — ^Winnebago County, Iowa. 



Buteo horealis (not Falco borealis Gmelin) ? Blakiston, Ibis, 1861, 318 (forks of 

 Saskatchewan). — Trippe, Proc. Essex Inst., vi, 1871, 113 (Minnesota). — 

 McChesney, U. S. Geol. and Geogr. Surv. Terr., Bull. 3, 1877, 684. 



Buteo borealis var. kriderii Hoopes, Proc. Acad. Nat. Sci. Philadelphia, xxv, 1873, 

 238, pi. 5 (Winnebago County, Iowa; coll. Acad. Nat. Sci. Philadelphia). 



Buteo borealis kriderii American Ornithologists' Union, Check-list, 1886, No. 

 337a; ed. 2, 1895, 130; ed. 3, 1910, 157.— Ridgway, Man. North Amer. Birds, 

 1887, 233.— Brewster, Auk, vi, 1889, 70 (Sapelo Island, Ga., Feb. 16, 

 1888). — Goss, Hist. Birds Kansas, 1891, 261 (Kansas; descr.; spec). — 

 Bendire, Life Hist. North Amer. Birds, i, 1892, 212. — Hatch, Notes Birds 

 Minnesota, 1892, 186, 452 (Minnesota; spec; records). — Cooke, Birds 

 Colorado, 1897, 74 (res. on plains). — Beyer, Proc Louisiana Soc Nat. for 

 1897-99 (1900;, 99 (Louisiana in winter).— Gary, Auk, xviii, 1901, 233 (Black 

 Hills, Wyo.; rare).— Bailey, Handb. Birds Western United States, 1902, 156 

 (descr.; distr.). — Kumlien and Hollister, Bull. Wisconsin Nat. Hist. Soc, 

 iii, 1903, 63 (Wisconsin; habits).— Arnow, Auk, xxi, 1904, 277 (St. Marys, 

 Ga., Feb. 3, 1904).— Woodruff, Chicago Acad. Sci. Bull. 6, 1907, 94 (Des 

 Plaines River, 30 miles nw. of Chicago, July 25, 1876). — Widmann, Birds 

 Missouri, 1907, 95. — Beyer, Allison, and Kopman, Auk, xxv, 1908, 441 

 (Louisiana, rare winter vis.). — Cory, Publ. Field Mus. Nat. Hist. No. 131, 

 1909, 462 (casual in Illinois and Wisconsin). — Swann, Monogr. Birds Prey, 

 i, 1926, 391 (monogr.). — [Arthur], Birds Louisiana, 1931, 198 (descr.; stat.; 

 Louisiana).- — Anderson, Condor, xxxvi, 1934, 79, in text (Elden Mountain, 

 Ariz.; spec.j. — Taverner, Condor, xxxviii, 1936, 67 through 71, in text 

 (crit.; distr.; color; hybridizing); Auk, liii, 1936, 360, in text (crit.). 



Buteo borealis krideri Coues, Check-list North Amer. Birds, 1873, No. 351c; Key 

 North Amer. Birds, ed. 2, 1884, 545. — Ridgway, in Baird, Brewer, and 

 Ridgway, Hist, North Amer. Birds, iii, 1874, 284; Proc. U. S. Nat. Mus., 

 iii, 1880, 194; Nom. North Amer. Birds, 1881, No. 436.— Roberts and 

 Benner, Bull. Nuttall Orn. Club, v, 1880, 17 (nesting; Minnesota). — Goss, 



