268 NORTH AMERICAN JJIKD.S. 



The present form is very nearly related to the true B. sivainsoni, and, 

 though distinguishable, we find it difficult to express points of absolute dif- 

 ference. The essential distinctions, however, are the longer primaries and 

 lighter colors of the present bird, there being in tlie immature plumage of 

 o.qjpterus no api)roach to the deep, fine oehraceous, the characteristic and 

 prevalent tint of the young B. swainsoni. The spots beneath are more 

 sparse, and there does not appear to be that tendency to their aggregation 

 on the sides of the breast as generally seen in swainsoni. 



Both agree, however, — and difl'er from all other species, — in the unbarred 

 slate-color of the under surface of primaries, the plain black of the outer 

 surface, conspicuous " mustache," obscurely barred gray tail, etc. In fact, 

 the general pattern is almost exactly the same, while there is little differ- 

 ence in relative proportions. 



In view of the very appreciable, though rather indefinite, differences 

 above indicated, and the oljscure history of the present bird, we prefer, at 

 least until more familiar with its different stages, to recognize it under the 

 above name. 



A third specimen, from Buenos Ayres (Couchitas ; William H. Hudson), 

 — exactly similar, in all particulars, to the two specimens described, • — was 

 labelled by Mr. Sclater, B. albicatulatns, Vieill., which is usually placed as a 

 syuonyme under B. pterodcs, an exclusively South American species ; though 

 belonging strictly to the same section of the genus with the present bird and 

 B. swainsoni, it is quite distinct, the Smithsonian Collection containing 

 numerous examples illustrating the several stages of plumage. 



Habits. Taking the two varieties together, this species appears to range 

 over the entire continent of America, from the Arctic regions to the cold-tem- 

 perate portion of South America. In Arctic America it appears to have a 

 western distribution, though extending far to the north during the breeding- 

 season, and being more or less nomadic during the winter. A single well- 

 marked specimen was taken by Mr. Brewster, in the winter of 1871-72, in the 

 eastern part of ilassachusetts. It was first noticed by Dr. Eichardson, and 

 was by him supposed to be identical with the common Buzzard of Europe. 

 It was met with in the fur country, where it was migratory, arriving there 

 early in April, and departing again about the end of September. It frequented 

 the low alluvial points of land which stretch out under the high banks 

 of rivers, where it might be observed sitting for a long while motionless on 

 the bough of a tree, waiting patiently for some small birds or quadrupeds to 

 pass within its reach. As soon as it perceived anything of the kind, it would 

 glide silently into the air and sweep easily but rapidly down upon its pre}'. 

 One of Dr. Richardson's specimens was found to have two whole toads in its 

 stomach. 



Dr. Eichardson states that this Buzzard liuilds its nest on a tree, of short 

 sticks, lining it sparingly with deer's hair. The eggs, from three to five in 

 number, are described as equalling in size those of the domestic fowl, and 



