Do you see that small olive-green bird sitting very erect on that fence-post? There—it suddenly springs into the air, flutters up and down for just half a moment, and then returns to the post. It is a flycatcher, and for hours together it will go on catching insects just in that same way. As it alights it tells us its name, calling Phœ-e-be, Phœ-e-be in a sad sort of voice, though there is no reason to think it is sorrowful at all. If we should go down to that bridge over the stream in the valley we would find its solid nest of moss and mud among the stones of one of the piers.
The woodland path is not so good a place for birds as are more open spaces; but one hears here the distant cooing of a dove, the chip-chur-r-r shout of the scarlet tanager, as red as fire everywhere except on its black wings and tail, and often the tapping of a woodpecker. There is one at work now on that tall dead stub. If you want to see him you must keep perfectly still, for if he notices that he is watched he begins to think some harm may follow, and either flies away or stops work, scrambling around the trunk and peering out from behind it with one eye to see what you mean to do next. See how firmly he clings to the trunk. If you were close enough you could see that two of the large-clawed toes at the end of his short strong legs and feet were straight forward and two straight backward; and that he is also propping himself up by means of his short stiff little tail, which is bent inward, and really serves as a kind of natural camp-stool! Now he is pecking away at the bark with his strong chisel-like beak, and making the chips fly in all directions. Most likely the grub of some burrowing beetle is lying hidden in the wood below, and he is trying to dig it out. But he will not have to dig down to the very bottom of its tunnel, for he has a very long slender tongue with a brush-like tip; and this tip is very sticky. And with this, after he has enlarged the mouth of the burrow, he will lick out the little grub which is lying hidden away within it.
Now let us make our way to the path by the side of the stream.
What a number of galls there are on these oak-trees—some on the leaves, some hanging down from the twigs in clusters, like currants, and some growing on the twigs themselves! Do you know what causes them?
Well, a very tiny fly pricks a hole in a leaf, or a young shoot, by means of a kind of sharp sting at the end of her body, and in that hole she places an egg, together with a very small drop of a peculiar liquid. This liquid has an irritating effect on the leaf, or twig, and causes a swelling to grow; and when this has reached its full size, and become what we call a gall, a little grub hatches out of the egg, and begins to feed upon it. Sometimes there are several grubs in one gall. If we were to cut one of those large red and white "oak-apples" to pieces, probably we should find as many as a dozen, each lying curled up in a hollow which it had eaten out.
If a naturalist had to choose some one place in which to carry on his outdoor studies, he could find none better than the course of a small rural river, and a year's work would not exhaust it. Just now, in midsummer, he would be most interested in the nesting of the sunfish and minnows. Let us steal quietly to the brink, where the turf forms a little bank, a foot or so high, to which the bottom slopes up in clear sand and gravel, with here and there a clump of bulrushes. Let us lie down and scan this bottom through the clear water rippling gently by, keeping very quiet, so as not to alarm any fishes which may swim near, for they are the very fellows we wish to see.
Here comes a little one—a common shiner—no, a golden one—stealing cautiously toward an open space. A much smaller fish—not so big as your little finger—shoots past him and stops as suddenly as if it had run against a wall, then an instant later is off again so swiftly you can hardly see it move. No wonder it is called Johnny Darter! Meanwhile the shiner, a minnow in a scale-armor of burnished gold, moves slowly on. Where is he aiming? Ah! look over there. Do you see that low ring of sand, about as large as a dinner-plate, running about some clear gravel, as though the plate were strewn with small pebbles?
That is a nest of a sunfish; and look! did you see the swoop of that gray shadow from the bulrushes? The shiner turned and fled like a bright streak through the water; and now the gray shadow is poised over the dish-like nest, and we see that it is the blue-eared sunfish, or "punkin-seed," as you say the boys call it when they go a-fishing.
See how with its breast-fins it fans the gravel among which its eggs are lying. They are so small and transparent that we cannot see them, but they are there, and must be kept clean. So the fish stirs the water and the current sweeps away everything which may have lodged there while the owner was away for a few minutes. But he never goes far, for he must guard his treasures against enemies like the shiner and other fishes, salamanders, water-bugs, and the like, which would eat them if they dared.
Butterflies innumerable greet us and dance along the roadside, as if to see us safely home. Many are small and yellow, or white and yellow, with handsomely bordered wings, and they are greatly interested in the clover. Then we see plenty of little blues, very regular in outline, and with them various coppers, distinguished by their orange and brown colors, each with a coppery tinge and set off by black markings. The hair-streaks are brown, too, with delicate stripes for ornaments on the lower surface, which are shown neatly when the wings are closed upright above the back. Did you know this was one of the distinctive marks of a butterfly? A moth never holds its wings on high in that fashion.