Vol. XXXIl 



1914 ] Cameron, The Ferruginous Rough-leg. 159 



THE FERRUGINOUS ROUGH-LEG, ARCHIBUTEO FER- 

 RUGINEUS IN MONTANA. 



BY E, S. CAMERON. 



Plates XIV-XVIII. 



Nesting. 



This splendid bird is undoubtedly the most powerful hawk met 

 with in Montana, where it is usually called eagle, and its carrying 

 power is remarkable as the sequel will show. It does no harm, 

 but, on the contrary, wages unceasing warfare against such pests 

 as prairie dogs (Cynomys), gophers (Thomomys), and meadow mice 

 (Arvicola), and should therefore be universally protected; neverthe- 

 less it has unfortunately become very scarce, excepting in one or 

 two favored localities where it is strictly preserved. Although a 

 good deal has been written about the Ferruginous Rough-leg, 

 as the hawk is called in the American Ornithologists' Union 

 Check-list, I am not aware that it has hitherto been studied or 

 photographed at the nest. It used to be abundant in Montana, 

 as evidenced by the fact that Dr. J. A. Allen found it "next to 

 Falco sparverius, the most common species of the Falconidae," and 

 himself discovered several nests containing young. He continues: 

 "The nest is often a very large bulky structure, sometimes three 

 or four feet in diameter, built of coarse sticks, mixed with the ribs 

 of antelopes and buffaloes. It is placed on the ground or rocks, 

 usually near the summit of isolated buttes. The same nest is 

 apparently occupied for a series of years and annually repaired."^ 



I have seen the eyrie of this species in many varied situations in 

 Montana; such as trees, on pillars or ledges of rock, and the 

 shoulders or summits of badland buttes. The female begins to 

 lay at any time from the middle of April until the end of the first 

 week in May, according to the season, and deposits two, three or 



> Proceedings of the Boston Society of Natural History, Vol. XVII., June, 

 1874. 



