II
In May two boys in town wrote to me to explain to them the meaning of the egg-shells, mostly those of robins, that were to be seen lying about on the ground here and there. I supposed every boy knew where most of these egg-shells came from. As soon as the young birds are out, the mother bird removes the fragments of shells from the nest, carrying them in her beak some distance, and dropping them here
and there. All our song-birds, so far as I know, do this.
Sometimes, however, these shells are dropped by blue jays after their contents have been swallowed. The jay will seize a robin's egg by thrusting his beak into it, and hurry off lest he be caught in the act by the owner. At a safe distance he will devour the contents at his leisure, and drop the shell.
The robins, however, have more than once caught the jay in the act. He has the reputation among them of being a sneak thief. Many and many a time during the nesting season you may see a lot of robins mob a jay. The jay comes slyly prowling through the trees, looking for his favorite morsel, when he is discovered by a vigilant robin, who instantly rushes at him crying, "Thief! thief!" at the top of his voice. All the robins that have nests within hearing gather to the spot and join in the pursuit of the jay, screaming and scolding.
The jay is hustled out of the tree in a hurry, and goes sneaking away with the robins at his heels. He is usually silent, like other thieves, but sometimes the birds make it so hot for him that he screams in anger and disgust.
Of the smaller birds, like the vireos and warblers, the jay will devour the young. My little boy one day saw a jay sitting beside a nest in a tree, probably that of the red-eyed vireo, and coolly swallowing the just hatched young, while the parent birds were powerless to prevent him. They flew at him and snapped their beaks in his face, but he heeded
them not. A robin would have knocked him off his feet at her first dive.
One is sometimes puzzled by seeing a punctured egg lying upon the ground. One day I came near stepping upon one that was lying in the path that leads to the spring—a fresh egg with a little hole in it carefully placed upon the gravel. I suspected it to be the work of the cowbird, and a few days later I had convincing proof that the cowbird is up to this sort of thing. I was sitting in my summer house with a book, when I had a glimpse of a bird darting quickly down from the branches of the maple just above me toward the vineyard, with something in its beak. Following up my first glance with more deliberate scrutiny, I saw a female cowbird alight upon the ground and carefully deposit some small object there, and then, moving a few inches away, remain quite motionless. Without taking my eyes from the spot, I walked straight down there. The bird flew away, and I found the object she had dropped to be a little speckled bird's egg still warm. I saw that it was the egg of the red-eyed vireo. It was punctured with two holes where the bird had seized it; otherwise it had been very carefully handled. For some days I had been convinced that a pair of vireos had a nest in my maple, but much scrutiny had failed to reveal it to me.
Only a few moments before the cowbird appeared I had seen the happy pair leave the tree together, flying to a clump of trees lower down the slope of the hill. The female had evidently just deposited
her egg, the cowbird had probably been watching near by, and had seized it the moment the nest was vacated. Her plan was of course to deposit one of her own in its place.
I now made a more thorough search for the nest, and soon found it, but it was beyond my reach on an outer branch, and whether or not the cowbird dropped one of her own eggs in place of the one she had removed I do not know. Certain am I that the vireos soon abandoned the nest, though they do not always do this when hoodwinked in this way.
I once met a gentleman on the train who told me about a brood of quails that had hatched out under his observation. He was convinced that the mother quail had broken the shells for the young birds. He sent me one of the shells to convince me that it had been broken from the outside. At first glance it did appear so. It had been cut around near the large end, with the exception of a small space, as if by regular thrusts or taps from a bird's beak, so that this end opened like the lid of a box on a hinge, and let the imprisoned bird escape. What convinced the gentleman that the force had been applied from the outside was that the edges of the cut or break were bent in.
If we wish rightly to interpret nature, to get at the exact truth of her ways and doings, we must cultivate what is called the critical habit of mind; that is, the habit of mind that does not rest with mere appearances. One must sift the evidence, must cross-question the facts. This gentleman was a lawyer,
but he laid aside the cunning of his craft in dealing with this question of these egg-shells.
The bending in, or the indented appearance of the edge of the shells was owing to the fact that the thin paper-like skin that lines the interior of the shell had dried and shrunken, and had thus drawn the edges of the shell inward. The cut was made by the beak of the young bird, probably by turning its head from right to left; one little point it could not reach, and this formed the hinge of the lid I have spoken of. Is it at all probable that if the mother bird had done this work she would have left this hinge, and left it upon every egg, since the hinge was of no use? The complete removal of the cap would have been just as well.
Neither is it true that the parent bird shoves its young from the nest when they are ready to fly, unless it be in the case of doves and pigeons. Our small birds certainly do not do this. The young birds will launch out of their own motion as soon as their wings will sustain them, and sometimes before. There is usually one of the brood a little more forward than its mates, and this one is the first to venture forth. In the case of the bluebird, chickadee, high-hole, nuthatch, and others, the young are usually a day or two in leaving the nest.
The past season I was much interested in seeing a brood of chickadees, reared on my premises, venture upon their first flight. Their heads had been seen at the door of their dwelling—a cavity in the limb of a pear-tree—at intervals for two or three
days. Evidently they liked the looks of the great outside world; and one evening, just before sundown, one of them came forth. His first flight was of several yards to a locust, where he alighted upon an inner branch, and after some chirping and calling proceeded to arrange his plumage and compose himself for the night. I watched him till it was nearly dark. He did not appear at all afraid there alone in the tree, but put his head under his wing and settled down for the night as if it were just what he had always been doing. There was a heavy shower a few hours later, but in the morning he was there upon his perch in good spirits.
I happened to be passing in the morning when another one came out. He hopped out upon a limb, shook himself, and chirped and called loudly. After some moments an idea seemed to strike him. His attitude changed, his form straightened up, and a thrill of excitement seemed to run through him. I knew what it all meant; something had whispered to the bird, "Fly!" With a spring and a cry he was in the air, and made good headway to a near hemlock. Others left in a similar manner during that day and the next, till all were out.
Some birds seem to scatter as soon as they are out of the nest. With others the family keeps together the greater part of the season. Among birds that have this latter trait may be named the chickadee, the bluebird, the blue jay, the nuthatch, the kingbird, the phœbe-bird, and others of the true flycatchers.
One frequently sees the young of the phœbe sitting in a row upon a limb, while the parents feed them in regular order. Twice I have come upon a brood of young but fully fledged screech owls in a dense hemlock wood, sitting close together upon a low branch. They stood there like a row of mummies, the yellow curtains of their eyes drawn together to a mere crack, till they saw themselves discovered. Then they all changed their attitudes as if an electric current had passed through the branch upon which they sat. Leaning this way and that, they stared at me like frightened cats till the mother took flight, when the young followed.
The family of chickadees above referred to kept in the trees about my place for two or three weeks. They hunted the same feeding-ground over and over, and always seemed to find an abundance. The parent birds did the hunting, the young did the calling and the eating. At any hour in the day you could find the troop slowly making their way over some part of their territory.
Later in the season one of the parent birds seemed smitten with some fatal malady. If birds have leprosy, this must have been leprosy. The poor thing dropped down through a maple-tree close by the house, barely able to flit a few feet at a time. Its plumage appeared greasy and filthy, and its strength was about gone. I placed it in the branches of a spruce-tree, and never saw it afterward.