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,