Every creature born into the natural world brings with him, I think, two ingrained or hereditary impulses for his salvation in moments of danger. One, for use when he is young and helpless, is to crouch motionless at the appearance of the enemy (opposite). The other, which appears later and explains why with rare exceptions any so-called savage beast is not to be feared unless wounded or cornered, is to take to his heels at the first warning that danger is loose in the neighborhood.
To the first impulse, here called "the saving instinct," birds and beasts of prey are possible but improbable exceptions. It may be that fox cubs, for example, which spend their early days in a den beyond human sight, do not hold still when alarmed, but it is significant that you never hear them, not a stir or a whimper, if you lay an ear down to the mouth of their den, though their keen ears or noses tell them of an enemy at hand. Later, when they are grown large enough to play in the sunshine, I have repeatedly observed that at any alarming noise—a sharp whistle on my part, or the bark of a dog in the distance—they invariably freeze in their tracks. After a quiet moment or two, long enough to make up what they would call their minds, they either resume their play or else slip quickly into the den, to be seen no more until the vixen returns and calls them out.
As for birds of prey, if ever you have watched young hawks or owls from your perch in a neighboring tree you may have noticed how still they commonly are, and how at any unnatural commotion they flatten down in the nest to become a part of the lifeless structure. Climb the nest tree now, slowly, carefully, with plentiful halts to quiet any feeling of alarm, and the moment your hat appears in sight the nestlings lift themselves up and open their mouths for food, evidently mistaking your hat or your shadow for the returning mother bird. Not till they recognize you as an enemy, too late, will they bristle their pinfeathers and hiss fiercely to scare you.
Of other young birds and animals, called the hunted in distinction from the hunting kind, one might say with Isaiah, a very observant prophet, "Their strength is to sit still." Three wholly natural reasons for their strength or salvation in time of danger are as follows:
First of all, the youngling that holds motionless close to earth cannot be seen, or at least he is seldom noticed by wild eyes. But be not misled here by any theories of "protective coloration," wherewith many naturalists please and deceive themselves. It is doubtless true, concerning the lower orders of animate life, that their pigment cells have a strange affinity, let us call it, for the coloration of their immediate environment. Thus, a flounder will quickly change the color of his back to match the color of the bottom on which he rests, as many insects harmonize their hues with that of the leaf or twig which supports them. By careful experimentation, Sir Edward Bagnell Poulton, Fellow of the Royal Society and professor of zoology at Oxford, apparently proved that the chromatophores (pigment cells) in the skin of a fish respond to any prolonged color impression received by the visual cells of the retina, with the result that his skin turns gray when his eyes see gray continuously, or turns brown when his eyes see brown. It has also been proved that the skin of a blinded fish invariably turns blackish, and black is not a color but the absence of all colors. What causes this mysterious color "affinity" between the body of a fish and his environment, or to what end, is still a matter of speculation on our part. Nature lets us see the change but refuses to reveal why she makes it.
Among the higher orders, whose color-pigment cells are less active and much less changeable, the simple fact is that a fawn with bright orange coat sprinkled with spots of glaring white has the same "invisibility" as a mottled brown grouse in the same place, so long as fawn or grouse holds quiet, but not a moment longer. Whatever the coloration, any bird or animal betrays himself by the first motion.
Next, from the hunting viewpoint, every bird or beast of prey associates life with motion so habitually, so completely, that a resting grouse or rabbit, or even a man, is in his eye only a part of the restful earth. To quote but a single example, I was sitting under a tree on the lake shore, watching a female sheldrake or scurry duck which had probably hidden her newly hatched brood and was now expertly catching minnows for them. Suddenly a hawk swooped with a paralyzing whirr of stiffened pinions. The sheldrake escaped by a flashing dive, losing only a few feathers, and the hawk wheeled in to perch on a branch so near my face that I dared not even wink. When his head was turned to look for his vanished prey I reached out a hand to grab his legs and bring him with threshing wings into my lap.
All theories to the contrary notwithstanding, I maintain that this wary hawk was deceived not by any protective coloration on my part but only by my quietude. And what did he think or feel, I wonder, when on being tossed free into the air he hovered a moment to glare down at me with fierce eyes before winging away to safety.
Finally, any wild bird or animal, excepting only a gorged beast of prey, gives off so very little scent when at rest that the keenest nose may pass without receiving a telltale message. This has been many times proved to my own satisfaction, at least, by having wild animals draw near without showing any sign of alarm at the dreaded man scent, paying me no attention until their eyes caught a purposeful motion, when commonly they came nearer instead of running away.
The same surprising thing was proved to anybody's satisfaction, I should think, by my setter Rab, whom I had trained to obey every word or whistle or hand signal before taking him to my summer camp. At home he honored his training by giving no heed to anything but game birds. In the wilderness, where he was occasionally permitted to range on either side while I followed an old logging road or fished a trout stream, he found a new world to his liking, and made the most of it by pointing everything he found as staunchly as ever he pointed grouse or woodcock in the home covers. On one occasion it might be only a deermouse; on another, a rarely seen fisher or "black cat"; on a third, when I approached his point, I heard the terrifying urumphumph of a startled bear.
One afternoon while following a dim trail through an alder swamp I missed Rab at heel, where he belonged in such a tangle, and went back to find him on point, his head turned to a dense thicket. And there on a low branch, hidden by bluejoint grass, was a junco nest, my first, with three or four squirming fledglings and a mother bird chirping uneasily over them. She had probably "frozen" when the man passed but was stirred to anger at sight of the dog, and that stir had betrayed her to his keen nose.
Again, in marked contrast, I took Rab at heel to where a fawn was hidden, being careful to pass on the downwind side to let any drift, of air bring its message to the setter's nostrils. Many times he had pointed deer for me; but now, though we were near enough for my eye to see the fawn as the doe had left him—flattened close to earth, neck outstretched, eyes closed—the setter gave no sign of scenting game; instead he lay down, in accord with his training, till I was ready to move on. So far as one could detect, the fawn never moved a muscle, and we left the little innocent undisturbed.
When confronted by danger, a mother quail or a mother partridge will act as if she has suddenly gone crazy-clucking, squealing, tumbling at your feet, doing everything she can think of to take your attention away from her chicks.
Any prowler would leap for the conspicuous big bird, naturally, and follow her until she whirred up and away, thus saving herself by flight after saving her chicks. Repeatedly, after disturbing a brood of quail or partridge I have hidden to watch them, and not once did they move until the mother bird returned to call them out of hiding. How long they would hold still if the mother failed to return is not known; but once, after waiting a full hour near a brood of wild ducklings without seeing the slightest motion, I went away leaving them still invisible.
Another illustration of this same saving instinct came in my familiar Connecticut woods, where an old ruffed grouse proved that he was mindful of the impulse which had doubtless been more than once his salvation when he was a helpless chick.
While roving the Redding hills with a young setter, Hiyu, in quest of flight woodcock, I flushed from underfoot a large grouse at the extreme edge of a cedar thicket. He was a cock, to judge by his resplendent ruff and perfectly barred tail, and he had probably skulked into hiding on hearing a distant rustle of leaves under the dog's feet. Remembering the alarming scarcity of his kind in this locality, I sent after him a devout hope that the next time he met a man with a gun he might have the sense to double back into cover, instead of roaring out over a hillside pasture where anybody could hit him. My next thought, born of acquaintance with grouse habits and hideouts in the locality, was that I might drop my hat over that careless cock if he would hold still long enough.
With the setter at heel we followed the bird's line of flight to a granite ledge, which dropped off steeply to a level some 50 or 60 feet below. Along its foot grew a dense fringe of brush, with here and there a wild grapevine or an impenetrable tangle of catbriars. Beyond was a downhill slope with scattered clumps of bayberry, here called candlewood because its clustered gray berries make sweet-smelling candles.
Hardly were we seated on the ledge top when a Cooper's hawk hove in sight; and though he kept well away at first, having seen our approach, his every line and motion spelled "hunting." As he cruised warily outside the brush below the ledge, his head frequently turned to one point on the outer edge of it; which told me as from a book that he had seen my partridge drop into cover and was now watching for his chance to swoop. The tireless hawk is hereabouts one of our worst game-bird killers, and in his head now was a single idea: the partridge was his game, not mine, and he was bound to have it.
I was looking down at the point he indicated, searching through every opening in the leafless brush for a glimpse of the hidden cock, when a double clap-clap of wings sounded overhead. The hawk was up there, hovering over the spot where his game had vanished; but though evidently hungry he remembered caution and veered away when I looked up. So he reminded me that wild birds and animals are most fearful of a man when they read from his eye that he sees them. After a wide circle the hawk returned to hover a brief moment above where his game was hidden, and plainly now one could both see and hear him clap his wings together.
That is a favorite ruse of the snowy or arctic owl, who may have learned it by the necessity of detecting white hares or white ptarmigan crouched on snow-covered ground; but never before had I seen it used by a hawk, and its meaning was unmistakable. This hungry predator knew but could not see where the grouse was hidden, and was clapping his wings to startle the game into a betraying motion.
It was now on my part a choice between hunter and hunted; one or the other must die, and when next the hawk wheeled within range he fell just outside the point he had been so keenly watching. The overeager young setter went down the ledge at the shot, laming himself by a head-over-heels tumble. He was pointing the dying hawk when I made my own way down, more carefully; on his muzzle were bloody scratches made by sharp talons when he tried to retrieve such armored game as he had never before seen. At my approach there was a violent stir of matted grass under the sweet fern, within five or six feet of where the hawk lay with Hiyu standing over him. Out of the grass burst the cock on thundering wings, to shoot like a bolt up over the ledge top.
Whether he had seen the hawk when he dropped into his chosen cover cannot be known; but he had certainly seen the hovering enemy, had heard the alarming clap of wings and the terrifying gunshot, had both seen and heard the dog come tumbling down; yet he had remained "frozen" during all the uproar, obeying his saving instinct, moving no muscle until the man appeared on blundering feet. Then, thinking himself safe at last, he headed back on speedy wings to the cedar thicket from which we had flushed him.
A partridge, however frightened he may be, is like a deer in that he never for a moment loses his sense of locality or of direction. You can drive him just so far, but not a yard beyond. On coming to new or strange territory he invariably doubles back to the familiar range he has known ever since he was born.
Mankind, I think, has a remnant or survival of that same saving instinct. Though we feel it but seldom, being accustomed to obey a conscious or reasoning mind instead of a subconscious or wholly natural impulse, it reappears in full force at moments when we are caught, as it were, off-guard. Witness your own involuntary freezing in your tracks at the sudden appearance of an overwhelming danger. Witness, also, your mental attitude in a frightful dream, when the imagination conjures up pain and terror as your portion, but the quiescent body receives no message from a suspended will.
To a naturalist the significant feature of your dream of great peril is that you cannot move, being for the moment governed by the subconscious impulse which holds a helpless young animal quiet, for his salvation, at the approach of an enemy.