300 



NORTH AMERICAN BIRDS. 



pariifivo Zoblosry, Cambridjrc, 10; Cab. G. N. Lawrence, (1; Coll. W. S. Browor, 3; R. 

 Iti(lf,nvay, 4. Total, 8.j. 



Med.iiirenieiil.'i. 



Tliat all the North Ainericau Uoiigh-leg},'ed Hawks, wliether light or dark 

 (excepting of course the -.•l.y('/v'«//i/i('(^s), aro one species, and also one race, 

 tiiere aji])ears to be but little doubt ; a critical conijiarison and minute ex- 

 amination of about one hundred specimens also proves that the dark plu- 

 mage, usually separated as " A. sancti-johiDinis" has notiiing to do witli age, 

 sex, season, or locality, but that, as in Butiv bonvlis var. cu/uriis and B. 

 sindnsmii, it is a purely individual condition, black birds being black, and 

 light birds being light, from ihe iirst iduniage till death. Each phase has its 

 young and adult stages distinctly marked, as the above diagnoses point out. 

 It liowever ajipears to be the fact tiiat certain regions are frequented more 

 by birds of one color than anotiier, and of the many hundreds of specimens 

 sent from the Arctic regions to tlie .Smithsonian Institution by officers of the 

 Hudson's Hay Company, none exhibited tlie blackish plumage which, on the 

 other hand, ajijiears most abundant about Hudson's Bay. 



The Nortli American birds are distinguishable from European ones (var. 

 Ingopns) by the characters given in the synopsis on p. 1G19, and description, 

 on p. 16 24. 



H.VBiTS. Tlie Rough-legged Hawk of Nortli America bears so close a 

 resemblance to the Eur()i)ean species, in all respects, — plumage, habits, and 

 eggs, — that the two are generally considered to be identical. Tiie distriliu- 

 tion of tlie American variety appears to be nearly tlironghout the entire 

 Union, from the Atlantic to the coast of the I'acific, and from New INlexico 

 to the Arctic cgions. It was taken at Fort Steilacoom, and at Shoal-water 

 Bay in Washington Territory, by Drs. Suckley and Cooper. It was not seen 

 by Mv. Dresser in Texas nor by Dr. Woodhouse in New Mexico, but it was 

 taken near Zuni by Dr. Kennerly, was found from Mimbres to the liio 

 (irande by Dr. Henry, and obtained near Fort Fillmore by Captain Pope, 

 and at Fort Massachusetts by Dr. Peters. 



Tlie Ikough-legged Hawk is quite abundant in spring and fall in the 

 neighljorliood of Niagara Falls. In the fall of 1872, ]\Ir. James Booth met 

 witli a pair of this species, accompanied Ity their young. Tlie latter were 

 fully grown. The male bird was in very black i)lumage, while the female 

 was unusually light, the pair thus presenting well-marked illustrations of 

 the two types, the black .i((iirfi-Jo}iiinni<s and the common la(/o]ms. The 

 l)arents were secured, and are now in the museum of tlie Boston Society of 

 Natural History. One of the young was also shot, but I did not see it. 



