Читать книгу The Woodpeckers - Eckstorm Fannie Hardy - Страница 3

Did you ever see a hairy woodpecker strolling about a tree for what he could pick up?

There is a whur-r-rp of gay black and white wings and the flash of a scarlet topknot as, with a sharp cry, he dashes past you, strikes the limb solidly with both feet, and instantly sidles behind it, from which safe retreat he keeps a sharp black eye fixed upon your motions. If you make friends with him by keeping quiet, he will presently forgive you for being there and hop to your side of the limb, pursuing his ordinary work in the usual way, turning his head from side to side, inspecting every crevice, and picking up whatever looks appetizing. Any knot or little seam in the bark is twice scanned; in such places moths and beetles lay their eggs. Little cocoons are always dainty morsels, and large cocoons contain a feast. The butterfly-hunter who is hoping to hatch out some fine cecropia moths knows well that a large proportion of all the cocoons he discovers will be empty. The hairy woodpecker has been there before him, and has torn the chrysalis out of its silken cradle. For this the farmer should thank him heartily, even if the butterfly-hunter does not, for the cecropia caterpillar is destructive.

But sometimes, on the fair bark of a smooth limb, the woodpecker stops, listens, taps, and begins to drill. He works with haste and energy, laying open a deep hole. For what? An apple-tree borer was there cutting out the life of the tree. The farmer could see no sign of him; neither could the woodpecker, but he could hear the strong grub down in his little chamber gnawing to make it longer, or, frightened by the heavy footsteps on his roof, scrambling out of the way.

It is easy to hear the borer at work in the tree. When a pine forest has been burned and the trees are dead but still standing, there will be such a crunching and grinding of borers eating the dead wood that it can be heard on all sides many yards away. Even a single borer can sometimes be heard distinctly by putting the ear to the tree. Sound travels much farther through solids than it does through air; notice how much farther you can hear a railroad train by the click of the rails than by the noise that comes on the air. Even our dull ears can detect the woodworm, but we cannot locate him. How, then, is the woodpecker to do what we cannot do?

Doubtless experience teaches him much, but one observer suggests that the woodpecker places the grub by the sense of touch. He says he has seen the red-headed woodpecker drop his wings till they trailed along the branch, as if to determine where the vibrations in the wood were strongest, and thus to decide where the grub was boring. But no one else appears to have noticed that woodpeckers are in the habit of trailing their wings as they drill for grubs. It would be a capital study for one to attempt to discover whether the woodpecker locates his grub by feeling, or whether he does it by hearing alone. Only one should be sure he is looking for grubs and not for beetles’ eggs, nor for ants, nor for caterpillars. By the energy with which he drills, and the size of the hole left after he has found his tidbit, one can decide whether he was working for a borer.

But when the borer has been located, he has yet to be captured. There are many kinds of borers. Some channel a groove just beneath the bark and are easily taken; but others tunnel deep into the wood. I measured such a hole the other day, and found it was more than eight inches long and larger than a lead-pencil, bored through solid rock-maple wood. The woodpecker must sink a hole at right angles to this channel and draw the big grub out through his small, rough-sided hole. You would be surprised, if you tried to do the same with a pair of nippers the size of the woodpecker’s bill, to find how strong the borer is, how he can buckle and twist, how he braces himself against the walls of his house. Were your strength no greater than the woodpecker’s, the task would be much harder. Indeed, a large grub would stand a good chance of getting away but for one thing, the woodpecker spears him, and thereby saves many a dinner for himself.

Here is a primitive Indian fish-spear, such as the Penobscots used. To the end of a long pole two wooden jaws are tied loosely enough to spring apart a little under pressure, and midway between them, firmly driven into the end of the pole, is a point of iron. When a fish was struck, the jaws sprung apart under the force of the blow, guiding the iron through the body of the fish, which was held securely in the hollow above, that just fitted around his sides, and by the point itself.

The tool with which the woodpecker fishes for a grub is very much the same. His mandibles correspond to the two movable jaws. They are knife-edged, and the lower fits exactly inside the upper, so that they give a very firm grip. In addition, the upper one is movable. All birds can move the upper mandible, because it is hinged to the skull. (Watch a parrot some day, if you do not believe it.) A medium-sized woodpecker, like the Lewis’s, can elevate his upper mandible at least a quarter of an inch without opening his mouth at all. This enables him to draw his prey through a smaller hole than would be needed if he must open his jaws along their whole length. Between the mandibles is the sharp-pointed tongue, which can be thrust entirely through a grub, holding him impaled. Unlike the Indian’s spear-point, the woodpecker’s tongue is barbed heavily on both sides, and it is extensile. As a tool it resembles the Solomon Islander’s spear. A medium-sized woodpecker can dart his tongue out two inches or more beyond the tip of his bill. A New Bedford boy might tell us, and very correctly, that the woodpecker harpoons his grub, just as a whaleman harpoons a whale. If the grub tries to back off into his burrow, out darts the long, barbed tongue and spears him. Then it drags him along the crooked tunnel and into the narrow shaft picked by the woodpecker, where the strong jaws seize and hold him firmly.