ho 
BIRDS—BUTEONINAE—BUTEO BAIRDIL 21 
the descriptions given above, the principal difference between the specimens before us, and is 
very probably dependent on age, and perhaps sex. 
This handsome and interesting species appears to be exclusively an inhabitant of western and 
northern North America. 
The plates represent this bird in the first and third plumages described above. 
List of specimens. 
Measurements. 
Il to ond 
Locality. When collected. Whence obtained. Remarks. Collected by— 
Mouth of Yellow Stone river...... July 14, 1856..... Lieut. Warren. ...)seeeee es eeen cere cece Dr. Hayden.... 20.63 48.5) 15.50 
Mouth of White Earth river ...... | 46. 
Knife river, Missouri... 50 OC 
Heart river, Nebraska .. 22 
Cochetope Pass.....-seeecece cece seeeeeecen cece eees Lieut. Beckwith. 
sesece|cosese GO. .occe vavccccesccccececccs|scnccssccccses cece! seccces 
San Luis valley ...... aoe 
Captain Pope ......)...... Gums and feet 
Pecos river, Texas... 
eEllOW ......) cccccccccccccese 22-00) HA.) 16.50 
BUTEO BAIRDIL, Hoy. 
Baird’sBuzzard. 
Buteo Bairdii, Hoy, Proc. Acad. Philad. VI, 451, (1853.) ss 
Cassry. B. of Cal. and Texas, pl. 41. 
Entire upper parts dark brown, with a purplish bronzed lustre, especially on the wings ; plumage of the head and neck behind 
edged and tipped with yellowish white ; upper tail coverts yellowish white, with transverse bars of brown ; tail above brownish 
cinereous, with about ten narrow bands of brownish black, and tipped with white; under parts pale yellowish white, or fawn 
color, with a few ovate and sagittate spots of dark brown; a stripe of dark brown running downwards on each side from the 
corners of the mouth ; cere, legs, and irides yellow. 
Older 2—Upper parts very dark brown, or nearly black, with a purplish lustre ; under parts with almost every feather having 
a large spot of brownish black, which color predominates on the breast, presenting a nearly uniforn color with the upper parts ; 
throat with narrow stripes of the same color; flanks and inferior wing coverts with circular and oval spots of white ; tibie dark 
brown, with transverse bars and circular and oval spots of reddish white ; upper tail coverts reudish white, with their outer 
edges brown, and with transverse stripes of the same ; under tail coverts yellowish white, with transverse stripes of brown; 
forehead white ; cheeks yellowish white ; stripes from the corners of the mouth wide and conspicuous. 
Total length, 18 to 20 inches; wing 15, tail 8 inches. 
Hab.—Northern and western North America. Spec. in Mus. Acad. Philadelphia and Nat. Mus. Washington. 
In the plumage, first described above, this bird bears some resemblance to the young of Buteo 
lineatus, but has a much more mature appearance, and is easily distinguished by its smaller 
size. It resembles also in colors only the young of Buteo pennsylvanicus, but is much larger. 
Though discovered in the State of Wisconsin, specimens from various western localities are in 
the collections of the expeditions. 
Specimens recently collected by Lieutenant Warren show that the upper figure of our plate, 
as cited above, really represents the young plumage. Lieutenant Warren’s specimens are 
scarcely fully fledged, and yet agree precisely with this figure. 
