XXXI. THE GREEN WOODPECKER.

We live so closely and familiarly with nature on the isolated hilltop, where my cottage is perched, that we often behold from our own drawing-room windows pretty rural sights, which seem intensely strange to more town-bred visitors. A little while since, for example, I was amused at reading in an evening newspaper a lament by a really well-informed and observant naturalist on the difficulty of actually seeing the night-jar, or fern-owl, alight upon a tree, and stand, as is his wont, lengthwise, not transversely to the branch that bears him. Now, from our little bay lattice that doubting Thomas might see the weird bird nightly, not twenty yards off, the whole summer through, crooning its passionate song, full in view of our house, from a gnarled old fir-tree. So again this morning, at breakfast, we raised our eyes from the buttered eggs and coffee, and they fell at once on a big green woodpecker, creeping upward, after his fashion, along a russet-brown pine-trunk, not fifteen feet from the place at table where we were quietly sitting. One could make out with the naked eye the dark olive-green of his back, relieved by the brilliant crimson patch on his gleaming crown. For several minutes he stood there, clambering slowly up the tree, though we rose from our seats and approached quite close to the open window to examine him. When he turned his head, and listened intently after his tapping, with that characteristic air of philosophic inquiry which marks his species, the paler green of his under parts flashed for a second upon us; and when at last, having satisfied himself there was nothing astir under the bark of the stunted pine, he flew away to the next clump, we caught the glint of his wings and the red cap on his head in motion through the air with extraordinary distinctness.

The yaffle, as we call our red-headed friend in these parts, is one of the largest and handsomest of our woodland wild birds. About a foot in length, by the actual measurement, “from the end of his beak to the tip of his tail,” he hardly impresses one at first sight with a sense of his full size, because of his extreme concinnity and neatness of plumage. A practical bird, he is built rather for use than for vain gaudy display; for, though his colour is fine, and evidently produced by many ages of æsthetic selection, he yet sedulously avoids all crests and top-knots, all bunches and bundles of decorative feathers protruding from his body, which would interfere with his solid and business-like pursuit of wood-burrowing insects. How well-built and how cunningly evolved he is, after all, for his special purpose! His feet are so divided into opposite pairs of toes—one couple pointing forward and the other backward—that he can easily climb even the smooth-barked beech-tree, by digging his sharp claws into any chance inequality in its level surface. He alights head upward, and moves on a perpendicular plane as surely and mysteriously as a lizard. Nothing seems to puzzle him; the straightest trunk becomes as a drawing-room floor to his clinging talons. But in his climbing he is also aided not a little by his stiff and starched tail, whose feathers are so curiously rigid, like a porcupine’s quills, that they enable him to hold on and support himself behind with automatic security. Long ancestral habit has made it in him “a property of easiness.” A practised acrobat from the egg, he thinks nothing of such antics; and when he wishes to descend he just lets himself drop a little, like a sailor on a rope, sliding down head uppermost, and stopping himself when he wishes by means of his claws and tail, as the sailor stops himself by tightening his bent fingers and clinging legs round the cable he is descending.

But, best of all, I love to watch him tapping after insects. How wise he looks then! how intent! how philosophic! When he suspects a grub, he hammers awhile at the bark; after which he holds his head most quaintly on one side with a quiet gravity that always reminds me of John Stuart Mill listening, all alert, to an opponent’s argument, and ready to pounce upon him. If a grub stirs responsive to the tap, tap, tap of his inquiring bill—if his delicate ear detects a cavity, as a doctor detects a weak spot in a lung with his prying stethoscope—in a second our bird has drilled a hole with that powerful augur, his wedge-shaped beak, has darted out his long and extensile tongue, and has extracted the insect by means of its barbed and bristled tip. The whole of this mechanism, indeed, is one of the most beautiful examples I know of structures begotten by long functional use, and perfected by the action of natural selection. It is not only that the bill is a most admirable and efficient boring instrument; it is not only that the tongue is capable of rapid and lightning-like protrusion; but further still, the barbs at its ends are all directed backward, like the points of a harpoon, while the very same muscles which produce the instantaneous forward movement of the tongue press at the same time automatically on two large salivary glands, which pour forth in response a thick and sticky secretion, not unlike bird-lime. The insect, once spotted, has thus no chance of escape; he is caught and devoured before he can say “Jack Robinson” in his own dialect.

But though the green woodpecker is so exceedingly practical and sensible a bird, built all for use and very little for show, he is not wholly devoid of those external adornments which are the result of generations of æsthetic preference. Dominant types always show these peculiarities. His ground-tone of green, indeed, serves, no doubt, a mainly protective function, by enabling him to escape notice among the leaves of the woodland; and even on a tree-trunk he readily assimilates with the tone of the background; but his brilliant crimson cap is a genuine piece of decorative adornment, which owes its origin, no doubt, to the selective preferences of his female ancestors for endless generations.