252 Caaieron, The Golden Eagle in Montana. [jilly 



consists of an immense pile of pine sticks, rests upon, and is built 

 around, a number of green boughs, Avhile a dead projecting branch 

 near the center forms a convenient perch for the parent eagles. 

 As would naturally be expected in the present case, the vertical 

 height of the nest greatly exceeds the diameter, and its width is 

 much inferior to the nest upon the rock previously described. 

 Nevertheless, as seen from below, it conveys an impression of 

 strength, which is not belied when it is reached, for a six foot man 

 can sit in it with ease. On May 11, the whole external circum- 

 ference of the nest rim was interwoven with an ornamental binding 

 of green pine tops. 



This pair of eagles are of course fully adult, and both have un- 

 varied dark brown tails. The female resembles the male of the 

 Fallon eagles across the Yellowstone and would appear to be a 

 uniform chocolate brown but for a few white scapulars, and some 

 white splashes on the greater wing coverts. The male is similarly 

 flecked with white, but a distinct ferruginous cast overspreads his 

 plumage. As early as February 25, the male eagle was observed 

 to tumble in the air. I first witnessed this remarkable evolution 

 on March 14, 1904, but have observed it several times since. To 

 the best of my knowledge no previous writer has alluded to this 

 habit of the Golden Eagles although it is common to both sexes in 

 the breeding season. It recalls at once the spring tumbling of the 

 male Marsh Hawk (Circus hiidsonius) which is even more extraor- 

 dinary from the fact that the hawk turns somersaults in the air» 

 On March 12, 1905, I paid special attention to this display on the 

 part of the male eagle which happened at the time to be sitting on 

 a pine at my Dawson County ranch. Soaring skward, he sud- 

 denly closed his wings, and dropped head-foremost like a spent 

 rocket, until the increasing impetus was checked by spreading 

 them. After his first tumble the eagle shot upwards and repeated 

 it, when he returned to the tree before resuming his aerial per- 

 formance. The bird employs a somewhat similar manoeuvre,, 

 but poised at a lower elevation, for capturing prairie dogs, to which 

 I shall again refer. 



At the above mentioned date (Feb. 25) the Knowlton eagles were 

 observed to be patching up their nest, and, while this seemed to 

 give promise of a very early brood, the downy young eventually 



