55. Tern’s nest and eggs in drift débris.

However, the few young that were seen gave a most interesting exhibition of their instinctive appreciation of the value of both their protective colors and the power of their legs. As long as they believed themselves unobserved they trusted in the former; but the moment they became convinced that a further attempt at concealment was useless, they transferred their faith to their pedal extremities, on which they pattered off as far and as fast as their strength permitted. This observation was verified later on Penikese,[57] where young were numerous, and the habit was well shown by the young bird figured.[56] He was discovered squatting among the rocks, where he remained, practically at my feet, while I set up my tripod and deliberately made his picture—during which operation so inconspicuous was he that I invariably had to hunt for him each time I removed my eyes from the exact spot in which he was crouching. Wishing now to show him to better advantage, he was picked up and placed on a wisp of driftweed. At once his manner changed. My touch had broken the spell; what could be felt could be seen, and, whereas before he had been as motionless as the pebbles about him,[57] his one object now was to get out of sight as speedily as possible. Consequently, time after time, the moment I took my hand from him he was off, and it was only by squeezing the bulb the moment he was released that I succeeded finally in securing his picture on the seaweed.

56. Young Tern hiding on rocky beach.

Young Terns, apparently, spend at least two days in the nest, during which time they are brooded by the parents; then they wander about within a limited space seeking the shade of a stone or bit of driftwood, always of course under the parental care. At Penikese, young of the year were seen on the wing, and the series of pictures shown represents the stages of growth from the egg to the age at which the bird takes flight.

57. Young Tern hiding in the grass.

Both the nature of the bird’s haunts and the manner in which the members of a colony spread an alarm make it practically impossible to surprise a Tern upon its nest. But by lying prone upon the ground one attracts far less attention than when standing. The hovering flock of birds gradually disperses, and those which are incubating soon return to the vicinity of their nests, hanging over them and dropping nearer and nearer,[53] until at the end of fifteen or twenty minutes they swoop down beside them, raise their wings high over their backs, then fold them gently and settle upon their eggs.[58]

On a second visit to the island a bit of old sail was brought, which I drew over me when lying on the ground—a plan resulting in my practical disappearance, as far as the Terns were concerned.