THE AMERICAN EAGLE HERRICK 265 



on either side of a deep gorge, and were said to have been used 

 in alternation by the same birds for the space of 15 years ; the one 

 on a large rock a mile from the north end of the island then con- 

 tained two eggs; while the other, on a hillside amid grass, was then 

 in disuse; the latter was so high that a man standing beside it 

 could not see into its shallow top. 



When the site is well chosen the nest is securely held in the grasp 

 of a number of spreading branches. Possibly any tree offering 

 such conditions might be taken, but I have seen only the sycamore, 

 the hickory, and the elm thus used, and the fact that a given pair 

 of eagles will sometimes favor the same kind of tree for a number 

 of successive nests is a strong argument for the force of habit. 

 Where the upright branches are nearly vertical, the nest, as in that 

 formerly at North Springfield, Ohio, gradually assumes a cylin- 

 drical form (pi. 1) ; where the spread is greater, the aerie takes 

 the cup form and later that of the wineglass or tall inverted cone 

 (pi. 2) ; in an exceptional case at Kelley's Island, to be later noticed, 

 the aerie was remarkably symmetrical and in shape of a huge bowl 

 over 7 feet in diameter (pi. 3) ; but it should be noted that such 

 comparisons apply to the exterior only, since " cup " and " bowl " are 

 here solid to nearly the brim; indeed, in certain cases no concavity 

 exists, but the aerie is markedly convex at the top. The diameter 

 of a new as of an old nest will depend, as I have intimated, upon 

 the angle of divergence of its main supports, but in a number of 

 instances observed the first year's nest measured 5 feet across the 

 top and its height was approximately the same. 



A nest of the first year consists of a great mass of sticks, gathered 

 mainly from the ground, borne to the nest site in one or both talons 

 by either bird, and laid individually with aid of the bill; as this 

 mass of fagots grows, greater attention is paid to the periphery, 

 where the coarser materials are more carefully and more effectively 

 interlaid and adjusted; the center and interstices are filled with 

 dead weeds, cornstalks, and stubble, with incidentally considerable 

 earth introduced with pieces of sod and with weeds. It is no wonder 

 that with the growth of years the core of such a structure comes to 

 form a sodden mass of vegetable mold. The largest sticks which I 

 have taken from different nests were a yard long and 2 inches thick, 

 but many which I saw in a nest at Kelley's Island this summer 

 appeared to have a length of over 6 feet. I am not yet ready to speak 

 of the act of nest building in detail, but examination clearly indi- 

 cates that such sticks are mainly gathered from the ground. The 

 owner of the land on which the nest at North Springfield was situ- 

 •ated told me of having seen his eagles in nesting time fly against 

 the dead branch of a tree and, as it snapped with a sharp report, 



