Life histories of North American woodpeckers — Story, Setting & Ideas

al uninjured, the birds do some harm by scattering the seeds of these noxious plants. * * * Cambium, or the inner bark of trees, was identified in 23 stomachs. Evidently the hairy does but little damage by denuding trees of their bark. Mast, made up of acorns, hazelnuts, and beechnuts, was found in 50 stomachs. It was mostly taken in the fall and winter months, and appears to be quite a favorite food during the cooler part of the year.

Illustrating the quantities of insects eaten by individual birds, F. H. King (1883), Wisconsin, writes: “Of twenty-one specimens examined, eleven had eaten fifty-two wood-boring larvae; five, thirteen geometrid caterpillars; ten, one hundred and five ants; six, ten beetles; two, two cockroaches; two, nine oötheca of cockroaches; two, two moths; one, a small snail; one, green corn; one, a wild cherry; and one, red elder berries. * * * One of the above birds had in its stomach eleven wood-boring larvae (Lamides?) and twelve geometers; another, thirteen larvae of long-horn beetles and four cockroach oötheca; another, nine wood-boring larvae; and two others together had three wood-boring larvae, and nine larvae not coleopterous.”

V. A. Alderson (1890) published the following interesting note: “Last summer, potato bugs covered every patch of potatoes in Marathon County, (being my home county,) Wis. One of my friends here, found his patch an exception, and therefore took pains to find the reason, and observed a hairy woodpecker, making frequent visits to the potato field and going from there to a large pine stub a little distance away.

“After observing this for about six weeks, he made a visit to the pine stub and found, on inspection, a large hole in its side about fifteen feet up. He took his axe and cut down the stub, split it open, and found inside, over two bushels of bugs. All had their heads off and bodies intact.”

The woodpecker’s method of locating tree-boring larvae and its specialized apparatus for extracting them are so well described by Dr. Thomas S. Roberts (1932) that I cannot do better than to quote him, as follows:

The hairy woodpecker possesses in its tongue one of the most remarkably developed and perfectly adapted instruments for extracting the tree larvae from their tunnels. The tip is a rigid, barbed spear and can be thrust out to an astonishing distance by reason of greatly elongated, posterior horns which pass up over the back and top of the head and run together down in front of the right eye, around which they are coiled for almost the entire circumference of the socket! So that, the drilling into the tunnel accomplished, the tongue darts out, the inner ends uncoil, the spear transfixes the grub, and with little ado the larva is dragged from its retreat into the bill of the bird, pounded perhaps for a moment or two, swallowed forthwith or carried to the young, and this most perfectly contrived and highly efficient engine is once more ready for action. There has been considerable discussion as to how the woodpeckers locate the larvae, active or dormant, which are hidden deeply in the wood and for which they drill so unerringly. All the special senses of birds are very highly developed, and it seems probable that in this case hearing, touch, and smell all may play a part. The active grub, as it crunches the wood, makes a sound that would surely be audible to a bird with its keen sense of hearing. The tunnel produces a cavity which would give both a different sound and feeling on tapping over it. Such things as grubs have a strong odor, and it is probable that this plays a part also.

Forbush (1927) says: “Maurice Thompson asserts that the hairy woodpecker strikes its bill into the wood and then holds the point of one mandible for a moment in the dent thus made. He believes that the vibrations produced by the insect in the wood are then conveyed through the beak and skull of the bird to its brain.”

In winter this woodpecker comes readily to suet or meat bones hung up on our trees or feeding stations to attract birds. It is also said to feed on the carcasses of animals left in the woods by trappers or hunters and to pick the fat from fresh skins that the trapper has hung up to dry. Although often called a sapsucker, there is practically no evidence that it ever does any injury to trees in this way; any sap or cambium eaten is probably taken incidentally in its search for insects.