THE AMEEICAN EAGLE HERRICK 267 



was far advanced, on the 16th of the same month of the succeeding 

 year. The following happened at the Vermilion nest: A collector 

 ascended the tree and removed the first set of two slightly incubated 

 eggs on or about March 18, 1920, after which a second set was laid 

 and the young reared in due course. I have not yet definitely deter- 

 mined the exact period of incubation at Vermilion, being unwilling 

 to interfere in any way with the process until our observations on 

 all later phases of nest life were reasonably complete. From what 

 was seen this year, however, I am satisfied that the incubation did 

 not exceed four weeks. 



It is commonly said that eagles, when once settled down, occupy 

 the "same nest" year after year; it would be more exact to say 

 that the eagle builds anew each year, but uses the old nest as a 

 site for the new one. Like most other birds, it satisfies its building 

 instinct at a certain time every year, but, unlike most, it is chained 

 to a certain spot, which is its old nest. As a result of these yearly 

 increments the eagle's aerie gradually rises in height and, since it 

 must meet the spread of its main supports, it may increase steadily 

 in diameter often, as we have seen, taking the form of an inverted 

 cone or balloon, until at last the nest tree collapses under its ever 

 increasing burden. Such a structure from the standpoint of the 

 student, if not of the builder, is thus a compound or storied nest; 

 it might be compared to a stack of saucers, each of which represents 

 a " nest," or a unit which is yearly added to the pile, but becomes so 

 completely incorporated with what precedes as to be thereafter insep- 

 arable from it. 



II 



Of some eight nests of the American eagle which I have examined 

 in the south shore region of Lake Erie, two were at North Spring- 

 field, two at Danbury, and three at Kelley's Island, besides that at 

 Vermilion, the most remarkable of them all. 



T^^iile traveling on the Lake Shore Kailroad some years ago I 

 happened to notice an eagle's nest from the car window not a thou- 

 sand feet from the line at a point near Girard, in Pennsylvania ; as 

 this nest appeared to be of unusual size and occupied the top of a 

 dead truncated tree which stood quite alone, it aroused my curiosity. 

 After learaing that this great aerie had long been a landmark of 

 that region, being well known apparently to every workman upon the 

 r©ad, I resolved to pay it a visit. Upon reaching Girard in the fol- 

 lowing June I found to my keen regret that the old sycamore with its 

 famous nest had gone down in a gale of the previous winter, but from 

 photographs^ made before its fall (pi. 1), together with measure- 



^ By Mr. H. B. Denio, of Milesgrove, Pa. ; for a series of pictures of this nest, see 

 " The Eagle's Nest," St. Nicholas Magazine, Vol. XXIX, New York, 1902. 



