July, 1919 A RETURN TO THE DAKOTA LAKE REGION 159 On the posts where the Night Herons fished, Black Terns were frequently seen early in August feeding their young, with xvhose cries the shore resound- ed. While the crying young ones stood on the fence posts their parents would fly above, and hovering over them a moment, with long bills extended, feed them on the wing. A family was seen sitting in a row on some sliver in the lake, one day, and to my great amusement a Duck sitting near watched them, ?noving its head as they moved; but soon, as if tired of the confusion, it swam off to more quiet waters. In another place one of the facile-winged birds was seen see-sawing over the water catching insects for its evening meal. Darting hither and yon, the picturesque terns often added a sudden touch of life to a, quiet landscape. In one case, on an August afternoon when a row of cows stood cooling themselves in the shallow water shaded by the trees along shore, and Bank Swallows were skimming over the still white surface of the lake, suddenly a flock of the long-winged Black Terns swept in and darted about over the surface till the water seemed all a'move with long wings. In striking contrast .to these swift-flying birds of the air were the princi- pal residents of the east side of the lake, the Coots and Pied-billed Grebes. They are so frequently associated that it seems as if the marks that differen- tiate them at different ages might have developed through the long peribds of that association. As they are about the same size and both look blackish across the water,. they need distinguishing marks; 'and the dusky little boats carry good signals, both fore and aft. The white knife-blade bill of the Coot, which in full face seems almost to divide i?s physiognomy, is a striking charac- ter, but nature as if to make assurance doubly sure has, optically, cut off the tip of the bill of the Grebe by means of the dark band that .gives it the name of Pied-bill. The dark area around the bill and the dark chin mark of the Pied- bill ?eem thrown in for extra measure of contrast to the plain black, velvety head and slaty neck of the Coot. The rear light of the Coot, however, seems the crowning achievement of nature, for at times it suggests, in minature, the white rump patches that the antelope flashes in moments of danger. A good illustration of its directive value came to me one day. Out across the lake was a white spot--was it the head patch of the Ruddy or the white breast of the Wesern Grebe, I asked myself. Raising the glass, it proved the white under tail coverts of the Coot ! Nature is never satisfied, however. When her work seems done, her aim accomplished, she keeps on adding.artistic touches. In this case it is not the
exquisitely delicate pen and ink work with which she delights the artistic stu-
dent of protective coloration, but something more broadly effective--pose. The Coot goes about with long neck craned forward; the Squatty Pied-bill nervously lowers its flat snaky head. At too'great a distance for any of these points to be noted, the Pied-bill settles the question by rising and showing its white belly, or turning on its side and flashing its white Grebe breast. The young of the Coot and Pied-bill, while markedly different from their parents have easily distinguished characters, for v?ile the young Coot has a plain pale gray neck, the young Pied-bill has the characteristic markings of the downy Grebes--black and white stripes down the neck. The weak appealing notes of these Young were almost always to be heard along the wide tule border. of the east .shore of the lake; and when, during harvesting, the reaper cut the wheat by the Herons' corner, I was able to get down close to the curve of the shore and look up the irregular tule front with
