88 TEE POPULAR SCIENCE MONTHLY 



lived only long enough to crawl out of its shell, while a second egg was 

 bad. No sooner was the little one dead, than the work of reconstruc- 

 tion, that is building on the old site was begun, and the body of the 

 chick, treated as so much nesting material, was soon buried under new 

 layers of grass and chips (Fig. 18). This labor lasted for four days, 

 or as long as I was able to watch it, but as in the other cases described, 

 it was sure to be futile owing to the lateness of the season. 



Fish hawks and eagles are known to return to their old nests year 

 after year, adding fresh materials, that is, building on the old site, each 

 season. An eagle's nest of the first year (compare Figs. 20 and 21) 

 is broader than tall, but with the yearly increment of stubble and sticks 

 added to its top, it gradually rises in vertical height, until becoming 

 so much taller than broad, in certain situations it tends to topple over 

 from sheer weight. The older of the two nests of the white-headed 

 eagle, which are here shown (Fig. 21), was begun in the crotch of a 

 dead sycamore, 77 feet from the ground at North Springfield, Ohio, 

 in 1885, and occupied for fifteen years, or until January, 1900, when 

 this ancient landmark was laid low in a storm. With the aid of photo- 

 graphs, taken in May, 1899, 2 and by actual measurements which I later 

 made on the prostrate tree, the dimensions of this great nest were 

 exactly determined. It was nine feet high and six feet in diameter, 

 or three feet taller than broad, and contained rather more than three 

 cubic yards of wood, earth and stubble. The new nest (Fig. 20), 

 which was built in the spring of 1900, was examined and photographed 

 in June of the same year ; now after the lapse of a decade, it has much 

 the appearance of the older nest, having risen greatly in height. Such 

 a structure might be regarded as a kind of " multiple nest," being com- 

 posed of increments, corresponding in number to the years of occupa- 

 tion, the last " nest " being built on the site of that of the previous 

 year. 



But a more interesting fact, if true, is the statement of Audubon 3 

 and others that ospreys and eagles often repair their nests in the 

 autumn, as if in anticipation of the needs of the coming year. We can 

 readily accept the fact, but not the interpretation, for if such a practise 

 really occurs, it is plainly due to the rise of a new reproductive cycle, 

 which is begun but soon checked. The sporadic return of the nest- 

 building instinct at the close of the season is essentially the same in 

 hawk or gull, and can imply no more intelligent forethought in one 

 case than in the other. 



2 By Mr. H. E. Denio, of Milesgrove, Pa., to whose kindness I am indebted 

 for their present as well as a former use. 



"Audubon speaks only of the fish hawks, which he says but seldom alight 

 on the ground, as " when they collect materials' for the purpose of repairing 

 their nest at the approach of autumn." " Ornithological Biography," Vol. I., 

 p. 419, Edinburgh, 1831. 



