Page:Life Histories of North American Diving Birds.djvu/31

Rh Eggs.—The number of eggs to a set seems to vary greatly, though 3 or 4 seems to be the usual number, according to my experience; I have frequently found 5 or even 6, and I have taken one set of 11, but this was probably laid by 2 or 3 birds. Other writers report various numbers from 5 to 10. Apparently there are certain nests in which eggs are dumped indiscriminately by several birds, but never hatched. Other marsh-nesting birds, such as terns, ducks, and coots, occasionally drop their eggs in the grebes' nests.

The eggs of the western grebe are not handsome and not particularly interesting. They vary in color from dull bluish white or cream color to various shades of dirty buff or olive buff. They are unspotted, but the accumulated dirt on the rough shells often gives them a mottled effect, even after being washed. They are generally more or less nest-stained and are often plastered with mud or covered with bits of nesting material. The shell surface is always dull and lusterless and sometimes lumpy. In shape they vary from "elliptical ovate" to "cylindrical ovate." The measurements of 53 eggs in the United States National Museum average 58 by 37.5 millimeters; the eggs showing the four extremes measures 65 by 37.5, 61.5 by 40, and 50 by 34 millimeters.

Young.—The period of incubation is about 23 days. In Saskatchewan I have found downy young, recently hatched, as early as June 8, but the majority of eggs do not hatch until the last of June or early in July of that region. The young are graceful little fellows with long necks and small heads; they are quite precocious and they can swim and dive soon after they are hatched. Mr. Finley (1907a) writes in regard to them:

On two or three different occasions, we watched one of the little western grebes cut his way out of the shell and liberate himself. The wall of his prison is quite thick for a chick to penetrate, but after he gets his bill though in one place, he goes at the task like clockwork and it only takes him about half an hour after he has smelled the fresh air to liberate himself. After the first hole, he turns himself a little and begins hammering in a new place and he keeps this up till he has made a complete revolution in his shell, and the end or cap of the egg, cut clear around, drops off, and the youngster soon kicks himself out into the sunshine. It does not take his coat long to dry ; in fact, he often does not give it a chance, for his first impulse seems to be to take to water and ride on his mother's or father's back. The grebe chick never stays in the nest longer than a few hours. A chick that is just hatched is clothed in the most delicate coat of soft gray fur, lighter below and darker on top.

The first day, as I lay hidden in the tules waiting for a picture, I saw a pair of grebes swimming along only 20 feet distant. I could catch glimpses of them as they passed just beyond their nest. One of the birds carried a chick on Its back. The grebes have a way of taking their young with them, for the little fellows lie on the back just under the wing coverts with only their heads sticking out. At the slightest alarm the mother raises the feathers a trifle and covers the chick completely. One can readily tell when a grebe has a