^ ol i907 1 Cameron, Birds of Custer & Davenport Counties, Mont. 263 



Others again appeared black, or almost black, showing the melanistic 

 form, and a very few individuals were a uniform lavender, or bluish ash, 

 like the male Marsh Hawk (Circus hudsonius). I have never obtained 

 but two birds in this rare dress, but I feel satisfied it is the one ultimately 

 assumed by the adult male, which through a long succession of browns 

 moults into a mature plumage of lavender with white throat spot. Of 

 this cinereous phase I can find no reference in ornithological works, where 

 the old males are invariably, but I believe quite erroneously, described as 

 brown. The immature birds, both male and female of the same age, also 

 exhibit endless difference in coloration, and the attempt to trace their 

 progress to maturity has perplexed even so eminent an authority as Dr. R. 

 Bowdler Sharpe who states (in lit.): "The changes of plumage in these 

 buzzards are terribly difficult to follow." I returned to the ranch for a 

 250 Holland rook-rifle and walking out in the pasture killed twelve of the 

 Buzzards, at the same time restraining the cowboys from indulging in a 

 general practice with their Winchesters. The small crack of the rook rifle, 

 and the headlong fall of a bird from its perch, had no effect upon its com- 

 panions, but I believe a shot gun would have caused them all to take 

 wing further on. In a letter published in 'The Ibis' (Oct., 1891, pp. 623- 

 625), I gave the estimated number of buzzards at about a thousand; but 

 it became obvious afterwards that two thousand would have been nearer 

 the true count, as twenty trees each containing fifty birds give a total 

 of a thousand without including all those on the ground and in more dis- 

 tant cottonwoods. I may add that my wife and Mr. Coggshall (owner 

 of the ranch), who were present during the flight only saw the birds in 

 the saddle horse pasture, and computed their number at a thousand within 

 the enclosure. Six out of the twelve buzzards were sent to Dr. P. L. Sclater 

 and are now in the Natural History Branch of the British Museum. On 

 the following morning all the buzzards had vanished as completely as 

 the Assyrian host, and such an opportunity is never likely to occur twice 

 to any one observer, although I have since seen other small migrations 

 flying over at a considerable height — one flock over the town of Miles 

 City. Some members of the flocks which arrive in April remain here to 

 nest in June, the young being hatched out early in July, and are ready 

 to take wing at the end of that month. As soon as this happens all the 

 buzzards, fortunately for them, leave this part of the country. 



68. Archibuteo lagopus sancti-johannis. Rough-legged Hawk. — ■ 

 Formerly a common winter resident but, like the Golden Eagle, is becom- 

 ing very scarce from traps and poison put out for wolves. Also observed 

 in spring and fall. I have seen many specimens of these hawks in Montana 

 which perished in the above mentioned manner. Some were indistinguish- 

 able from three in my collection of Orkney birds while others were again 

 quite different. Here, prairie dogs appear to be the favorite food of this 

 species and the next, so that both should be strictly protected. I believe 

 that a few pairs breed in the badlands. On May 14, 189S, I discovered 



