The mating of animals, especially the calling of an unseen mate from a great distance, brings us [[162]]face to face with the same problem, and perhaps also the same answer. Sometimes the mating call is addressed to the outer ear, as in the drumming of a cock-grouse or the whine of a cow-moose; but frequently a mate appears when, so far as we can hear, there is no audible cry to call him. How do the butterflies, for example, know when or where to seek their other halves? That their meeting is by chance or blunder or accident is a theory which hardly endures an hour’s observation. In the early spring I take a cocoon from a certain corner of shrubbery and carry it to my house, and there keep it till the end softens, when I put it into a box with a screened top and hang it out under the trees. Presently a gorgeous moth crawls out of the cocoon; and hardly has she begun to wave her wings to dry them when the air over the screen is brilliant with dancing wings, the wings of her would-be mates. And the thing is more puzzling to me because I have never found a cocoon of that kind in my immediate neighborhood; nor have I seen a single cecropia this season until the captive called them.
How they find her so promptly is a problem that I cannot solve. It may be that the call is wholly physical or sensible, that some fine dust or aroma is sent forth on the air currents, and the sensitive nerves of other moths receive and respond to it; [[163]]but it is still amazing that wind-blown creatures can follow an invisible air-trail through what must be to them a constant tempest and whirlwind of air currents, until they come unerringly to the one desired spot in a limitless universe. I have shown that pretty sight of dancing wings to many audiences, after predicting what would happen; and always they saw it with wonder, as if there were magic in it.
The moth mystery may be dissolved by some such purely physical formula; but what physical sense will explain the fact that when I turned a modest hen-pheasant loose in the spring, in a region where my wide-ranging setter and I never discovered a pheasant, she was immediately joined by a gloriously colored mate, and soon there was a hidden nest and then young pheasants to watch? Most birds and beasts are questing widely in the mating season, and their senses seem to be more keen at this time, or more concentrated on a single object. On grounds of what we thoughtlessly call chance, therefore, they would be more apt to find mates when they are keenly looking for them; but giving them every possible chance in a wide region where the species is almost extinct, and then multiplying that chance a hundred times, I still find it hard to believe that the meeting of two rare animals is either accidental or the result of ordinary [[164]]sense-perception. Out of several examples that occur to me, here are two which especially challenge the attention:
One early spring a she-fox was caught in her den, some five miles from the village where I then harbored. She was carefully bagged, carried a few rods to an old wood road, placed in a wagon and driven over country highways to the village, where she was confined in a roomy pen in a man’s dooryard. A few nights later came a snowfall, and in the morning there were the tracks of a male fox heading straight to the vixen and making a path round about her pen. She was his mate, presumably, and when we found his tracks our first feeling of admiration at his boldness was soon replaced by the puzzling question of how he had found her so quickly and so surely. To answer that question, if possible, I followed his back trail.
Now the trail of a fox in the wilderness, where he is sometimes hunted by wolves or other hungry prowlers, is a bewildering succession of twistings and crisscrosses; in a settled region, where his natural enemies are extinct, his trail is bolder, more straightforward, easier to read; and in either case you can quickly tell by the “signs” whether your fox is male or female, whether hunting or roaming, or hungry or satisfied. Also you [[165]]can tell whether he is just “projeckin’ around,” as Uncle Remus says, or whether his mind is set on going somewhere. In the latter event he almost invariably follows runways, or fox roads, which are as well known to him as are footpaths and stream-crossings to a country lad. But the trail of this particular fox was different from any other that I ever followed. That he was a male and was “going somewhere” was evident enough; but he was not following runways or paying any attention to them. He left no signs at places where any ordinary dog-fox would surely have left them, and he was stopping to listen or to ward himself at uncommonly frequent intervals. So, running it backward, I read the story of his journey mile after mile, till the oncoming trail changed to the devious, rambling trot of a questing fox; and beyond that I had no interest in it.
The place where the fox seemed to have found his bearings, or where he stopped his rambling to head straight for his mate, was some four miles distant from the captive in a bee-line. The course he took was entirely different from that taken by the man who brought the vixen home, thus excluding the theory that he followed the trail by scent; and the latter part of his way led through the outskirts of a village, where the track of a fox had not been seen for many years. From the distant [[166]]hills he had come down through sheltering woods at a stealthy trot; across open pastures on the jump; over a bridge and along a highway, where he traveled behind a friendly stone wall; then very cautiously through lanes and garden fringes, where the scent of men and dogs met him at every turn; turning aside here for a difficulty or there for a danger, but holding his direction as true as if he followed a compass, till he came at last with delicate steps to where his mate was silently calling him. For except on the assumption that she called him, and with a cry that was soundless, I know not how to explain the fact that he found her in a place where neither he nor she had ever been before.
It is possible, you may reason, that this was not his first visit; that unknown to us, venturing among his human and canine enemies, he had by a lucky chance stumbled upon his mate on an evening when the bare ground did not betray his secret to our eyes; and that for his next visit he had cunningly laid out a different trail through manifold dangers. It was the latter trail, made without doubt or question of what lay at the end of it, which I had followed in the telltale snow.
The course he took was entirely different from that taken by the man who brought the vixen home.
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