Page:The Zoologist, 4th series, vol 1 (1897).djvu/139

Rh perfectly hidden; while the hen, at day-time, closely resembles a stone, bush, ant-heap, or any little inequality of the veld. One is surprised to see how close such a large bird can lie to the ground, and how even an Ostrich-farmer may almost walk over a sitting hen in full daylight without seeing her. The cock is simply indistinguishable at night, except to a practised eye, and then only at a few yards distance. It may be urged that the black of the cock is not a protection in the morning or afternoon during daylight. This is not quite correct. In the very early morning, or in the afternoon towards sundown, it is most difficult to distinguish him; and it is but for two or three hours altogether that he is in the broad daylight, that being the only time in the whole twenty-four hours when the nest is not protected in a singularly effective manner by the colour of the sitting bird. Even then, unless one is close to the nest, his low-lying, long-curved, motionless form blends so closely with the ground and surrounding objects as to be much more difficult to discover than an inexperienced person could believe.

As sitting continues, a little embankment is gradually raised around the nest, where the nature of the soil permits. This is not in the original plan of the nest, but is made during the incubation of the eggs. The sitting bird, while on the nest, sometimes pecks the sand up with its beak nearly as far from the nest as it can reach, and drops it around the body. A little embankment is thus gradually formed, and often, just outside, a shallow irregular trench, from which the soil has been taken. The formation of both is aided by a peculiar habit of the birds. When the bird on the nest is much excited (as by the approach of other birds or people), it snaps up the sand spasmodically without rising from the nest, and without lifting its head more than a few inches from the ground. The bank is raised by such sand as falls inward, and the trench is deepened.

The original nest, as has been pointed out, is merely a shallow depression, the earth scraped out being mostly scattered far and wide by the vigorous kicks of the cock. As sitting continues the depression is very liable to silt up again; this is aided by the bird scraping in sand now and then when working the