116 Bird — Lore
close. and the heavy head turning slowly on its axis settle down on the soft cushion again. If actually driven of? she would return in a second, and in another moment would be fast asleep,
On a quiet evening. just after sundown, the camera was mounted on a suitable platform. and two photographs were made of this sleeping bird without awaking her. In the first the plate was exposed for five and in the second for twenty minutes, both yielding good prints, allowing for'the regular movements of respiration,
The sleeping habits of birds do not appear to have received much at- tention. and are often difficult to observe.' That they vary not only in differ- ent species. but with the season and other conditions is obvious. When not breeding, many of the smaller perching birds seek the dense coverts or foliage, which afiotd protection from cold as well as from enemies, Grouse are sometimes found enclosed in light snow; Quail huddle in dense covies on the ground, where they pass the night; birds of prey, like Hawks and Eagles, sleep at odd intervals by day or night, with the head buried in the feathers of the back. The diurnal sleep of Owls and Goatsuckers is more readily observed. The male Robin has been known to pass the night at a long distance from its nest. ‘In a community of the great Herring , Gull, which knows no repose by day or night, the old birds take frequent naps at all hours, and either while on the perch or the nest. This Gull will occasionally doze with head drawn in and eyes closed, but usually conceals its head in its feathers like a Hawk or Vireo. But, if at the such times, the Gull is dull of sight, its hearing is keen, for at an alarm it will suddenly throw up its head and with outstretched neck scream loud enough to be heard for half a mile. Some of the Pheasants sleep with the head either drawn in on shortened neck, or turned back and concealed. So far as I have observed, the same bird always turns its head to the same side in sleep, and this seems to follow as a matter of course from the force of habit.
When we analyze the tameness of such a bird as the Vireo just de» scribed, we must recognize two elements which enter into the problem i in varying degreesmthe sum of its daily experiences and the strength of its instincts,- both of which are subject to constant variation. In this in- stance the strength of the brooding and other parental instincts undoubt- edly tended to allay the temporary sense of fear and to increase the apparent tameness obserVed. One cannot help feeling that such profound sleep could not conduce. in the long run, to great length of life in either - parent or oflspring.
This nest was not disturbed beyond removing some obstructing leaves. and was not watched beyond the tenth day. when the wing—quills were growing apace. We were glad to learn. however, that the broad was safely reared. and we hope it made a good passage southward in the fall.
