78 



strongty mai'kcd and rufous below, especi- 

 ally on thighs, and with more bars than 

 the sub-terminal one on tail ; melanisms 

 are frequent, but thej/ usually retain the 

 rufous tail.^ 



i'MSd. Bitteo borealis harlani- (Aud.), Bds. Am.,i., 

 pi. 86 (1830). [Near St. FrancisviUc, 

 Louisiana, type in Brit. Mus.] 

 Harlan's Hawk. 



a melanism of 

 S 380, ? 400- 



Dark phase : resembling 

 B. borealis kridcri ; wing 

 408 mm. ; nearly unifonii sooty-brownish- 

 black, with much less of concealed white ; 

 tail mottled with greyish, dusky and rufous, 

 with sub-terminal black band. Light 

 phase : resembling a small darker example 

 of B. b. borealis. 



Lower 

 Mississippi 

 Valley & Gulf 

 States, from 

 Texas and 

 Louisiana to 

 Florida. 



143e. Buteo borealis alascciisis Grinnell, Univ. Cal. 

 Pub. ZooL, v., No. 2, p. 211 (1909). [Glacier 

 Bay and C/iicliagof /.] 

 Alaska Red-tail. 



S.E. Alaska. 



Resembling B. boi calls calitrus, but smaller 

 throughout ; wing S 344-355 mm. ; ? 365- 

 370 mm. ; dark areas blacker and more 

 extended. 



143f. Buteo borealis costaricensis Ridg., Hist. N. Guatemala and 

 Am. Bds., iii., p. 285 (1874). [Costa Rica.] Costa Rica to 

 Central American Red-tail. Panama. 



' I have examined the type of B. coopcri Casein in the U.S. Nat'. i\Iui. and am 

 obHged to conclude it is an aberrant e.xamplc of this form. 



^ Even after examination of a number of available specimens in the United 

 States I am unable to discard this form as a melanism, since it seems to cover a 

 definite geographical area and to be smaller than B. b. borealis. Light birds, such 

 as those from Florida, with the rufous tail of B. borealis borealis, undoubtedly occur 

 in its area, but they equal it in size. Melanistic birds referrable to harlani occur in 

 ■Canada, .Mr. Taverner assures me, within the range of krideri ; yet it is impossible 

 to throw the range of harlani into that of krideri. 



