On this latter subject, Mr. Rathbun writes to me:
Lewis’s woodpecker is an expert at catching insects on the wing. When in this act, its perch is some vantage spot, such as the top of a dead tree or a bare limb in the open. Here it sits motionless, except to turn its head from side to side on the lookout for its prey; and when this is seen, the bird glides from its resting place to make a capture. On one occasion for more than an hour, we watched a pair of these woodpeckers seize flying insects, and in that length of time not less than 35 were taken. Through our field glasses we kept a close watch on the birds and soon learned from their actions when an insect was sighted, thus it was easy for us to anticipate its capture, and in not a single instance was a failure made by either of the birds. Once, a light puff of air changed the course of the insect just at the time it was about to be taken, but the woodpecker made a quick turn upward at the same time, dropped its legs straight down, and neatly made the take. When busy catching insects on the wing, this bird leaves its perch by easy wing beats or a long, slow, graceful glide; then, after its prey is caught, rises in its flight and, quickly wheeling, returns to its lookout station.
But, as if not content with hunting insects after the manner of a flycatcher, sometimes this bird mingles with the swallows as they hawk over the ground. On one occasion in summer, as we came to a very open pasture, we noticed numbers of barn and cliff swallows in flight over it after insects, and in company with them was a pair of Lewis’s woodpeckers. Back and forth over the meadow flew these dark birds, busy in an attempt to catch flying insects, and their actions as they flew were in marked contrast to those of the graceful swallows. Although we watched the woodpeckers for more than half an hour, throughout that time neither one alighted; and when we left the place both still coursed busily above the field.
About one-third of the food of Lewis’s woodpecker consists of acorns. It shares with the California woodpecker the interesting habit of storing acorns, though its method of storing them is quite different, for it seldom, if ever, makes the neat round holes to fit the acorns, so characteristic of the other species; and its stores of acorns are never so extensive, so systematic, or so conspicuous as those of the California woodpecker. Charles W. Michael (1926) writes:
Recently we watched a Lewis Woodpecker making trips back and forth between a Kellogg oak and his home tree, a cottonwood. He was busy storing away his winter supply of acorns. Occasionally he picked a fallen acorn from the ground; more often he flew into the lesser branches of the oak, and hanging like a great black chickadee he plucked the acorn from the cup. With crow-like flappings, his broad wings carried him back to the dead cottonwood with his prize in his bill. Alighting somewhat below the summit of his tree he would, by a series of flight jumps, come to a certain shattered stub where a fissure formed a vise. Into this he would wedge the acorn.
With the acorn held firmly in place he would set about cutting away the hull, and strong strokes of his bill would soon split away the shell and expose the kernel. But he was not satisfied in merely making the kernel accessible, he must go on with his pounding until he had broken it into several pieces, and then with a piece in his bill he would dive into the air like a gymnast, drop twenty or thirty feet and come with an upward swoop to perch on the trunk of the same tree. A few hitching movements would bring him to a deep crack that opened into the heart of the tree. Here he would carefully poke away, for future reference, his morsel. Usually the acorn was cut into four parts, involving four such trips, and on the last trip to the vise he would take the empty hull in his bill, and with a jerk of his head, toss it into the air. An examination of the ground beneath the tree disclosed hundreds of empty acorn shells. Holding a watch on the Lewis Woodpecker, we found that he made five trips in five minutes and stored five acorns.
J. Eugene Law (1929) has published another illuminating paper on this subject, which is well worth reading; he describes in considerable detail the woodpeckers’ methods in storing the meats of acorns in cracks in poles and indulges in some speculation as to the causes and purposes involved in the habit.
Herbert Brown (1902) found Lewis’s woodpeckers quite destructive to pomegranates and quinces, near Tucson, Ariz. On September 30 he counted ten in the pomegranate groves; “they were mostly feeding on pomegranate fruit. They first cut a hole through the hard skin of the fruit and then extract the pulp, leaving nothing but an empty shell.” Later, on October 13, he says: “Now that the pomegranate crop has been destroyed they have commenced to eat the quinces, of which there are large quantities. On the tops of some of the bushes I noticed that every quince had been eaten into, one side of the fruit being generally eaten away.”
William E. Sherwood (1927) writes:
On June 16, 1923, while collecting near Imnaha, Wallowa County, Oregon, I frightened a Lewis woodpecker from the top of a fence post where it was evidently having a feast. On top of the post it had left a fresh egg, probably its own; for it was absolutely fresh, of the right size, and unmarked. The shell had been broken into, but the contents not yet extracted.