Why may not the red-head’s occasional cannibalism, unless this is mere individual degeneracy, and his more common custom of hoarding be habits that he is acquiring? Why, indeed, may not the Californian woodpecker’s distinguishing trait be a habit which began like these among a few birds here and there, wiser or more progressive than the rest, and which in time became general and established? Why may not the two observed instances of the Lewis’s woodpecker be examples of a similar habit just beginning? The very differences in their methods point to that explanation. The Lewis’s woodpecker that had seen the Carpenter’s work tried to imitate him; the one that lived outside his range adopted a way of his own, unnoticed before among woodpeckers, and shelled and quartered his nuts before he stored them.
It is remarkable that these four woodpeckers are cousins; they belong to the same genus, and they have essentially the same structure, tastes, and habits. Why should it be strange if their minds were alike too? if they had a natural bent toward accumulativeness, and a natural desire to try new wrinkles? We are sure that one of them has acquired a new habit within a few years. Why may we not suppose as a basis and a spur to further investigation that the others also are acquiring ways new and strange?
XI
THE WOODPECKER’S TOOLS: HIS BILL
There is an old saying, “You may know a carpenter by his chips;” but, though chips are seldom long absent when a woodpecker is about, can we call the woodpecker a carpenter? Is he not both in his works and ways of working—with the one exception of the Californian woodpecker—more of a miner?
For the carpenter takes pieces of wood, bit by bit, and joins them together till at last he has built a lofty skeleton or framework for his dwelling, which last of all he covers over and closes in; and the tools he uses are saw and hammer. With these alone he could build his house, though it might be neither very large nor very good. When a carpenter’s house is finished, it is neither a cave nor a hole, but a pavilion built in the open air after the model of a spreading tree,—which frames a roof with its branches and shingles it with overlapping leaves. There is nothing in the woodpecker’s way of building which corresponds to that.
Quite different are the miner’s methods. In the West, where the barren mountain sides stretch up into snowclad summits, on the face of slopes as seamed and gray and verdureless as the wrinkled trunk of an aged oak, I have seen holes where human woodpeckers burrow. The entrance to a mine half-way up a hillside looks strikingly like a woodpecker’s hole and scarcely larger. Nor does the likeness vanish as we think how in their long tunnels inside their mountains of gold and iron and silver the delving miners are picking and prying and picking to lengthen their burrows just as the woodpeckers peck and pry and peck inside their wooden mountain, the tree-trunk. Which shall we call the woodpecker—a carpenter or a miner?
What are the miner’s tools? Pick and drill, are they not? What are the woodpecker’s? The same. Certainly we shall see, if we stop to think, that it is not a chisel that he uses, as we sometimes say. A chisel is a knife driven by blows of a hammer; like a knife its effectiveness depends upon the sharpness and length of its cutting edge. But a woodpecker’s bill is not a cutting tool. It is a wedge, but a wedge working on a different principle from a knife-edge. Look at this one and observe that, though strong and stout, it is not sharp and has no true cutting edge. It is a tapering, square-ended, flat-sided tool, rather six-sided at the base and holding its bevel and angles to the tip. The woodpecker’s bill is a pick, not a chisel. It is used like a pick, being driven home with a heavy blow and getting its efficiency from its own weight and wedge-shape and from the force with which it is impelled. Watch the downy woodpecker at his work and see what sturdy blows he delivers, pausing after each one to aim and drive home another telling stroke. This is pick-axe work. But sometimes he rattles off a succession of taps so short and quick that they blend together in one continuous drumming, too light and quick to be likened to the ponderous swing of the pick-axe. Now he is drilling. The work of a drill is to cut out a small deep hole either by twirling (as in drilling metals) or by tapping (as in drilling stone). The woodpecker drills by the latter method and there is a curious likeness between his bill and the mason’s tools.
