BIRDS—-BUTEONINAE—BUTEO MONTANUS. 2 
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 tibizw and under tail coverts so strongly 
barred as in the present bird. 
Dimensions.—Adult female, total length 23 to 25 inches, wing 163 to 17, tail 9 to 10 inches. Male, total length 19 to 22 
inches, wing 15 to 16, tail 814 to 9 inches. 
This is a species much 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 Rocky 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 Rocky 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 14 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. 
Measurements. 
= wb = 
SI 3 Loeality. When collected.) Whence and how ob- = Collected by— = =e S = = E 
e | $ tained. EI a8 | 5y,| 5s 
B| ez 3 Be ae Sala 
S| 3 2 oo leeuhe 
Oo | n fe) a F Es 
5836 | © | Fort Steilacoom, W.T.........-.| Aug. 
5834 Sept. 
4581 adéescloconpadccg vee Dees 
BGS y |e Ose atctateteis «UO stiow sles cicstsie es ealaictetesielats |'ssleleiejeviate eeesieis's Gove lala Stevenscecsicelh 9.998|| DrsBuckleyecscsideswecellssaeisiccatencneealee teres 
087 Gacbiag| [aqod cocdt Moparoaudcson.codrocodecud ado sogacoedasod Dr. Suckley 
4372 Oct. —, 1854 |...... fiiidecenodeeAbaneD 
8535 March 21, 1854 | Gov. Stevens 
8534 |...... Yakima river, W. T......+.0e000s Aug. 4, 1853 |...... dorsecce 
ASICs leeee KortiDalleswOw iccssicecsicciecte ess Dec. —, 1854 | Dr. Suckley.. 
S521) Fane Santa Claray Calvewcwersicoaseceshs|svewslsccsiases'cls Dr. Cooper... 
4611 | . ...| California. Leaner okie stelsieisiesieietese Major Emory.. 
8536 |...... GARIN de ctocerjarinesivisesicasiesiesicses Nov. 23, 1854 |...... COrstescclers 
8533 |...... Gampp4SSNe Mises ssciecenscloscses March 16, 1854 | Lieut. Whipple 
8549 |...... Campill4 Ne Misncsscsaeccssscess eo 6, 1854 | cee edO.. cececsenee cece 
6957 | 3 | North Platte... 
6956))|| Qe |easeciees dose eseeees 
4986 |...... Pecos river, Texas 
AQBS) |e ccccleuseccee dO vetentsieie 
8532 |......| Devil’s river, Texas 
