Page:Popular Science Monthly Volume 77.djvu/93

Rh chips, carry them to the chosen site, and go through the instinctive moulding and turning movements in the most approved and characteristic manner. The male even mounted the female, and was borne on her back like a circus-rider, in his evident attempt to perform an act

 and nearly twice as tall as broad; the predecessor of the nest shown In Fig. 20 In dead sycamore, three and one half feet in diameter at base; top of nest 77 feet from ground.

which is usually necessary. In this case, however, eggs were not destined to appear, and the new nest was eventually given up. This sporadic attempt at nest-building, while there are still chicks to be nursed, illustrates what we have described as the conflict of opposing instincts.

At the beginning of the breeding season in the gull, old nests are frequently reclaimed, and possibly by the same birds, though this has not been determined, or a new site is chosen, and a new nest built. If an addled egg is left after the others have hatched, "repairs" to the nest are frequently undertaken, and the old egg is either incubated for several days longer or it is buried out of sight. A pair of gulls, which was watched from the tent, had a single chick, and this one