Page:Popular Science Monthly Volume 77.djvu/94

88 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 reconstruction, 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 photographs, taken in May, 1899, 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 composed of increments, corresponding in number to the years of occupation, 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 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 nestbuilding 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.