BUTEO. 233 



or rufous (corresponding to the 

 white area of very light-colored 

 birds), but this is wholly obliter- 

 ated in the complete melanism. 

 Young : Darker throughout and 

 more heavily spotted beneath 

 than in true B. borealis, the plu- 

 mage sometimes wholly dusky 

 (except the tail), as in the adult. 

 Tail of adult always with a 

 black subterminal bar, and 

 frequently with several, 

 more or less complete, ad- 

 ditional bars. Eggs 2.31 X 

 1.80. Hab. Western North 

 America, south into Mexico, 

 east to Eocky Mountains 

 (casually to Illinois). 

 3376. B. borealis calurus 

 (Cass.). Western Red-tail. 

 i*. Tail of adult without any black bars ; other- 

 wise, much like B. borealis calurus. Hab. 

 Cape St. Lucas. 



337c. B. borealis lucasanus Eidgw. 

 St. Lucas Red-tail. 

 g 2 . Middle toe not more than 1.55 ; tail of adult (and 

 young) grayish brown, sometimes slightly touched 

 with rufous, crossed by an indefinite number (but 

 varying from about 10 to 13) of narrow bands of 

 dusky, which become gradually indistinct and 

 finally obsolete toward base. 



Plumage exceedingly variable, but usually a 

 mixture of sooty brown and whitish, in vari- 

 able relative quantity; sometimes entirely 

 dusky (except tail) and rarely almost entirely 

 white ; length about 20.00-23.00, wing 15.50- 

 16.60, tail 8.80-10.00, culmen .85-.95, tarsus 

 3.00-3.50, middle toe 1.40-1.55. Sab. Northern 

 portions of eastern hemisphere ; accidental in 

 Michigan ? 

 336. B. buteo (Linn.). European Buzzard. 

 c 3 . Middle toe not decidedly longer than bare portion of tarsus in 

 front ; length of cere on top greater than depth of bill at 

 anterior edge of cere. 



Plumage uniform black, or blackish brown, the feathers 

 30 



