Vol. XXXIl 



1914 



] Cameron, The Ferruginous Rough-leg. 161 



her legs and 'flags' were of the latter color barred with black. To 

 the casual observer, the color of these parts will mark the chief 

 difference between adult and immature birds. In first and second 

 plumage, at least, the legs and thighs are of such pale buff as to 

 appear white excepting in brilliant sunshine. Moreover, the tail 

 of the young bird has four dark bars and is white for the basal half 

 only, the terminal half being light slate color. 



In May, 1905, a second pair of hawks constructed an eyrie in 

 a cotton-wood tree about six miles from my Dawson County ranch. 

 A shepherd who happened to camp with his sheep wagon at this 

 place boiled and ate the three eggs, whereupon the disgusted birds 

 deserted it. Yet a third pair nested upon a ledge of a high butte 

 during 1908, when two eggs were laid, but the almost full-fledged 

 young were discovered by some sheep shearers in July, who killed 

 one and took the other captive. From three nests, therefore, 

 no young birds were reared, and one adult was inexcusably sacri- 

 ficed. 



Last summer, Mr. W. R. Felton, an engineer of the Chicago, 

 Milwaukee and Puget Sound Railway kept four nests of this hawk 

 under observation for me, and visited them whenever his work of 

 building a branch line between Lewiston and Great Falls allowed 

 him time. These four nests were within a radius of four miles 

 from the engineer's headquarters at the Square Butte Ranch, in 

 Chouteau County, and others were reported seven miles away. 

 Besides the above, Mr. Felton found four disused but well preserved 

 eyries, — two of them within a quarter of a mile of an occupied nest. 

 All eight nests were placed upon rocky ledges or points. They 

 were constructed of the same materials, which consisted of sage 

 brush and greasewood sticks, with some soapwood intermixed, and 

 lined with dry cow manure. As will be seen from the measure- 

 ments, the loose pile of sticks made the new nests remarkably high, 

 but they settled considerably before the young had flown. A 

 brief history of the four nests and their occupants condensed from 

 Mr. Fel ton's notes follows: Nest No. 1, which was only two miles 

 north of the Square Butte Ranch, and easily visible from there 

 through powerful binoculars, was visited almost every day. This 

 particular nest was picturesquely situated on a rock}' point of the 

 'Chalk Cliffs' northeast of the geologically famous " Square Butte," 



