BIRDS — ^BUTEONINAE — BUTEO MONTANUS. 



27 



In this plumage, which is evidently that of the young bird, the dark spots of the under parts are usually much larger and 

 more numerous than in the young of Buteo borealis, in which we have never seen the tibise and under tail coverts so strongly 

 barred as in the present bird. 



Dimensions. — Adult female, totariength 23 to 95 inches, wing 16| to 17, tail 9 to 10 inches. Male, total length 19 to 22 

 inghes, wing 15 to 16, tail 8>^ to 9 inches. 



This is a species mucli resembling and nearly related to the red-tailed buzzard (Buteo borealis) 

 of the States on the Atlantic, and in the examination of collections like the present made during 

 journeys across the continent, it is not without difficulty that a distinct range of locality can be 

 assigned to the two species. The most strongly characterized specimens of the bird now before 

 us are from the countries west of the Eocky mountains, but it is evident from specimens in this 

 collection that this species is not restricted to those regions. It not only inhabits the moun- 

 tains, but extends into the countries at their eastern base. 



Of this rather difficult and obscure species, we have in the present collection no less than 

 thirty specimens, which, with several others from the collection of the Philadelphia Academy, 

 make a series probably representing all the stages of plumage dependent on age, sex, or season. 

 This series admits of division into the three stages above described. 



Our comparisons are made with a series of twenty-eight specimens of Buteo borealis from 

 various parts of the United States east of the Eocky mountains ; generally, however, from the 

 vicinity of Philadelphia. The present species appears to be the'larger, averaging in total length 

 about 24 inches in adult females, which, so far as can be determined from prepared specimens, 

 is nearly two inches greater than the average of the same sex of Buteo borealis. The wing is 

 about 1^ inches longer. There are in the entire series of both species now before us not more 

 than three specimens that we have any difficulty in assigning to one species or the other, 

 though specimens of both constantly occur which cannot be recognized without difficulty, unless 

 series are at hand for comparison. 



List of specimens. 



Locality. 



When collected. 



Whence and how ob- 

 tained. 



Collected by — 



Measurements. 



II 



5836 

 5834 

 4581 

 8531 

 8538 

 4372 

 8535 

 8534 

 4416 

 4521 

 4611 

 8536 

 8533 

 8549 

 6957 

 6956 

 4986 

 4985 

 8532 



Fort Steilacoom, W. T. 

 do 



Aug. 

 Sept. 



8,1856 

 —,1856 



Dr. G. Suckley. 

 do 



527 



23.50 



24.50 



53.00 

 51.00 



16.75 



.do.. 



:do.. 



.do.. 



.do.. 



Shoalwater bay, W. T . 

 Yakima river, W. T.... 



Fort Dalles, O. T 



Santa Clara, Oal 



California 



Iiaguna 



Oampl49, N. M 



Camp 114, N.M 



North Platte 



do 



Pecos river, Texas 



do 



Devil's river, Texas , . . , 



Oct. — , 1854 

 March31,1854 

 Aug. 4, 1853 

 Dec. — , 1854 



Nov. 23,1854 

 March 16, 1854 

 Feb. 6, 1854 

 Aug. 1, 1857 

 .......do 



Dr. Potts 



Gov. 1. 1. Stevens. 



Dr. Suckley 



do 



Gov. Stevens 



do 



Dr. Suckley 



Dr. Cooper 



Major Emory 



do 



Lieut. Whipple... 



99 

 536 



Dr. Buckley. , 



Dr. Cooper . 

 do 



33.00 

 24.00 

 22.00 



49.00 

 54.00 

 48.00 



.do.. 



Nov. —,1855 



Lieut. Bryan .. 



do 



Oapt. Pope 



do 



IVfEyor Emory., 



14 

 185 



71 

 371 



A. Schott 



do 



Dr. Kennerly , 



do 



W. S. Wood.. 

 do 



!^.50 

 25.00 



54.50 

 53.00 



18.00 

 17.50 



Dr. Kennerly . 



