260 Cameron, The Golden Eagle in Montana. [juiy 



incubation, but assisted his partner to shelter the eaglets both from 

 the high winds and hot sun. If the shading hen bird happened to 

 observe me on the hilltop she would immediately squat flat in the 

 nest and imagine herself hidden. This habit was common to both 

 female eagles; their perplexed offspring vainly endeavored to 

 arouse them to a sense of their neglect as long as I remained near. 

 No attempt in the present case was made to secure photographs 

 of the downy white nestlings, as we already had a number, showing 

 them in every stage of plumage from two days old/ and we pre- 

 ferred to wait for the eaglets to leave the nest. Although smaller 

 than their badland congeners the Knowlton birds developed sooner, 

 and had entirely lost the fluffy white crop and chin at a month and 

 26 days old. This suggests the hypothesis that, while a diet of 

 grouse and hares makes the largest eagles, on the other hand, 

 birds fed exclusively on prairie dogs and snakes mature more 

 quickly. 



I was unable to verify from personal observation that adult 

 eagles, at least, devour rattlesnakes entire, including the head. 

 Although Sharp-tailed Grouse (Pedioecetes phasianellus campestris) 

 and Sage Grouse (Centrocercus urophasianus) were common in the 

 neighborhood, I only once saw a bird, or the remains of one, in or 

 near the nest. This solitary exception was on June 26, when 

 from the hilltop at 6 p. M. my wife and I (unnoticed) watched the 

 female eagle entirely pluck and dismember a Sharp-tailed Grouse 

 for her eaglets. The eagle, with her back to us, held the grouse 

 firmly down, by planting a foot at each end, on the now perfectly 

 flat nest. After first pulling out the wing quills, she next attacked 

 the soft clinging body feathers, and got rid of those which adhered 

 to her bill by violently shaking her head. The apparently full- 

 g^o^^Tl eaglets waited patiently one on each side of her, until their 

 supper was ready, and at this point the old bird perceived us and 

 flew away. The eaglets seemed half inclined to follow her exam- 

 ple but did not leave the branches. Next morning we were early 

 on the groimd with a camera and an ascent of the tree was attempted. 

 Before the eyrie could be reached, however, the female eaglet flew 

 strongly for upwards of a quarter of a mile and settled on the oppo- 



1 See Auk, Vol. XXII, No. 2. 



