52 THE HAWKS AND OWLS OF THE UNITED STATES. 



tenance for hordes of mice. At present in winter and early spring it 

 is not uncommon to see ten or fifteen Eed-tailed Hawks in different parts 

 of this flat attracted hither by the abundance of their natural food. 

 Prior to the reclamation of the flats not more than a pair or two were 

 to be seen in the same neighborhood during the winter. 



The Eed-tailed Hawk proper inhabits eastern North America west to 

 the Great Plains, north at least to latitude 60°, and south to eastern 

 Mexico, and probably breeds throughout most of this range, though 

 more commonly north of the parallel of 40°. In the West it is sepa- 

 rated into the three following geographical races, so that as a species 

 its range covers the whole United States : 



The Western Red-tailed Hawk {Buteo borealis calurus) inhabits the 

 country west of the Eocky Mountains, as well as portions of Mexico. 



Krider's Eed-tailed Hawk [Buteo borealis Jcriderii) is found in the 

 Great Plains from Minnesota to Texas, and extends east casually to 

 Illinois. 



Harlan's Eed-tailed Hawk {Buteo borealis harlami), which until re- 

 cently was considered a good species, dwells in the lower Mississippi 

 YaUey and Gulf States, east to Georgia, and extends casually to Iowa, 

 Illinois, and Pennsylvania. 



Two other races occur in North America south of the Mexican frontier, 

 one {Buteo borealis lucasanus) on the peninsula of Lower California, and 

 the other {Buteo borealis costaricensis) in Central America. 



DESCKIPTION. 



Adult. — Upper surface of tail deep rusty rufous with usually a black 

 subterminal band; above blackish brown, variegated with gray ftil- 

 vous and whitish; below white with more or less bufify, belly streaked 

 with dusky or brown. 



Immature. — Tail bright gray without any shade of red, and crossed 

 by six to ten regular dark bands. A pronounced blackish zone across 

 the upper part of the belly. 



In Harlan's Hawk the tail is mottled with rusty, white, gray, and 

 dusky; the rest of the plumage may vary from that of the typical red 

 tail to nearly black. 



The Western Eed-tail varies from a light extreme much like the typi- 

 cal Eed-tail to a uniform dark, sooty brown; and the tail usually has 

 more than one dark band. 



Krider's Hawk is light-colored with much white on upper parts and 

 entirely white or pale buff on lower parts. 



Length: 19 to 25 inches (482 to eSS""""); extent, 49 to 58 inches 

 (1245 to 1475°'™); wing, 13.50 to 17.75 inches (342 to 451"""); tail, 

 8.50 to 10.50 inches (216 to 267"""). 



