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When we consider the life of the cow-bird, how suggestive is this spectacle which we may see every year in September in the chuckling flocks ma.s.sing for their migration, occasionally fairly blackening the trees as with a mildew, each one the visible witness of a double or quadruple cold-blooded murder, each the grim subst.i.tute for a whole annihilated singing family of song-sparrow, warbler, or thrush! What a blessing, at least humanly speaking, could the epicurean population _en route_ in the annual Southern pa.s.sage of this dark throng only learn what a surpa.s.sing subst.i.tute they would prove--on toast--for the bobolinks which as "reed-birds" are sacrificed by the thousands to the delectable satisfaction of those "fine-mouthed and daintie wantons who set such store by their tooth"!
And what the cow-bird is, so is the Continental "cuckoo." Shall we not discriminate in our employment of the superlative? What of the throstle and the lark? Shall we still sing--all together:
"O cuckoo! I hear thee and rejoice!
Thrice welcome darling of the spring."
_DOOR-STEP NEIGHBORS_
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How little do we appreciate our opportunities for natural observation!
Even under the most apparently discouraging and commonplace environment, what a neglected harvest! A back-yard city gra.s.s-plot, forsooth, what an invitation! Yet there is one interrogation to which the local naturalist is continually called to respond. If perchance he dwells in Connecticut, how repeatedly is he asked, "Don"t you find your particular locality in Connecticut a specially rich field for natural observation?" The botanist of New Jersey or the ornithologist of Esopus-on-Hudson is expected to give an affirmative reply to similar questions concerning his chosen hunting-grounds, if, indeed, he does not avail himself of that happy aphorism with which Gilbert White was wont to instruct his questioners concerning the natural-history harvest of his beloved Selborne: "That locality is always richest which is most observed."
The arena of the events which I am about to describe and picture comprised a spot of almost bare earth less than one yard square, which lay at the base of the stone step to my studio door in the country.
The path leading to the studio lay through a tangle of tall gra.s.s and weeds, with occasional worn patches showing the bare earth. As it approached the door-step the surface of the ground was quite clean and baked in the sun, and barely supported a few scattered, struggling survivors of the sheep"s-sorrel, silvery cinquefoil, ragweed, various gra.s.ses, and tiny rushes which rimmed the border. Sitting upon this threshold stone one morning in early summer, I permitted my eyes to scan the tiny patch of bare ground at my feet, and what I observed during a very few moments suggested the present article as a good piece of missionary work in the cause of nature, and a suggestive tribute to the glory of the commonplace. The episodes which I shall describe represent the chronicle of a single day--in truth, of but a few hours in that day--though the same events were seen in frequent repet.i.tion at intervals for months. Perhaps the most conspicuous objects--if, indeed, a hole can be considered an "object"--were those two ever-present features of every trodden path and bare spot of earth anywhere, ant-tunnels and that other circular burrow, about the size of a quill, usually a.s.sociated, and which is also commonly attributed to the ants.
As I sat upon my stone step that morning, I counted seven of these smooth clean holes within close range, three of them hardly more than an inch apart. They penetrated beyond the vision, and were evidently very deep. Knowing from past experience the wary tenant which dwelt within them, I adjusted myself to a comfortable att.i.tude, and remaining perfectly motionless, awaited developments. After a lapse of possibly five minutes, I suddenly discovered that I could count but five holes; and while recounting to make sure, moving my eyes as slowly as possible, my numeration was cut short at four. In another moment two more had disappeared, and the remaining two immediately followed in obscurity, until no vestige of a hole of any kind was to be seen. The ground appeared absolutely level and unbroken. Were it not for the circular depression, or "door-yard," around each hole, their location would, indeed, have been almost impossible. A slight motion of one of my feet at this juncture, however, and, presto! what a change! Seven black holes in an instant! And now another wait of five minutes, followed by the same hocus-pocus, and the black spots, one by one, vanishing from sight even as I looked upon them. But let us keep perfectly quiet this time and examine the suspected spots more carefully. Locating the position of the hole by the little circular "door-yard," we can now certainly distinguish a new feature, not before noted, at the centre of each--two sharp curved p.r.o.ngs, rising an eighth of an inch or more above the surface and widely extended.
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What a danger signal to the creeping insect innocent in its neighborhood! How many a tragedy in the bug world has been enacted in these inviting, clean-swept little door-yards--these pitfalls, so artfully closed in order that their design may be the more surely effective. As I have said, these tunnels are commonly called "ant-holes," perhaps with some show of reason. It is true that ants occasionally are seen to go into them, but not by their own choice, while the most careful observer will wait in vain to see the ant come out again. Here at the edge of the gra.s.s we see one approaching now--a big red ant from yonder ant-hill. He creeps this way and that, and anon is seen trespa.s.sing in the precincts of the unhealthy court. He crosses its centre, when, click! and in an instant his place knows him no more, and a black hole marks the spot where he met his fate, which is now being duly celebrated in a supplementary fete several inches belowground.
A poor unfortunate green caterpillar, which, with a very little forcible persuasion in the interest of science, was induced to take a short-cut across this nice clean s.p.a.ce of earth to the clover beyond, was the next martyr to my pa.s.sion for original observation. He might have pursued his even course across the arena unharmed, but he too persisted in trespa.s.sing, and suddenly was seen to transform from a slow creeping laggard into the liveliest acrobat, as he stood on his head and apparently dived precipitately into the hole which suddenly appeared beneath him. A certain busy fly made itself promiscuous in the neighborhood, more than once to the demoralization of my necessary composure, as it crept persistently upon my nose. What was my delight when I observed the fickle insect in curious contemplation of a pair of calipers at the centre of one of the little courts! But, whether from past experience or innate philosophy in the insect I know not, the p.r.o.nged hooks, though coming together with a click once or twice at the near proximity of the tempter, failed in their opportunity, and the trap was soon seen carefully set again, flush with the ground at the mouth of the burrow.
The contrast of these clean-swept door-yards with the mound of debris of the ants suggested an investigation of the comparative methods of burrowing and the disposal of the excavated material. Here is a hole evidently some inches in depth; what, then, has become of the earth removed? Suiting action to the thought, I swept into the openings of two or three of the holes quite a quant.i.ty of loose earth sc.r.a.ped from the close vicinity, and thus completely obliterated the opening of burrow, door-yard and all.
I awaited in vain any sign of returning activity at the surface, and, my patience being somewhat taxed, I entered my studio, where I remained for a quarter of an hour, perhaps. Upon stealing cautiously to the doorway, I observed all the obliterated holes had reappeared, and upon taking once more my original position I was soon rewarded with a demonstration of the method of excavation. After a moment or two a pellet of earth seemed suddenly to rise from within the cavity, and when arrived at the level of the ground was suddenly shot forth a distance of five or six inches, as though thrown from a tiny round flat shovel, which suddenly flashed from the opening, and as quickly retired to its depths, though not without a momentary display of two curved p.r.o.ngs and a formidable show of spider-like legs.
After a short lapse of time the act was repeated, this time a tiny stone being brought to the surface, and, after a brief pause at the doorway, was jerked to a distance as from a catapult. I now concluded to try the power of this propelling force, and taking a small stone, about three-quarters of an inch in length and a quarter-inch in thickness, laid it over the mouth of the tunnel. A few minutes pa.s.sed, when I noticed a slight motion in the stone, immediately followed by a forcible ejectment, which threw it nearly an inch, the propelling instrument retiring so quickly into the burrow beneath as to scarce afford a glimpse. The stone appeared almost to have jumped voluntarily.
For an hour or more the bombardment of pellets and small stones continued from the mouth of the pit, until a small pile of the spent ammunition had acc.u.mulated at several inches distance, and at length the hole entirely disappeared, the earth in its vicinity presenting an apparently level surface--an armed peace, in truth, with the two touchy curved calipers on duty, as already described.
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Following the hint of past experience, I concluded to explore the depths of one of these tunnels, especially as I desired a specimen of the wily tenant for portraiture; and it is, indeed, an odd fish that one may land on the surface if he be sufficiently alert in his angling. No hook or bait is required in this sort of fishing. Taking a long culm of timothy-gra.s.s, I inserted the tip into the burrow. It progressed without impediment two, three, six, eight inches, and when at the depth of about ten inches appeared to touch bottom, which in this kind of angling is the signal for a "strike" and the landing of the game. Instantly withdrawing the gra.s.s culm, I found my fish at its tip, from which he quickly dropped to the ground. His singular ident.i.ty is shown in my ill.u.s.tration--an uncouth nondescript among grubs. His body is whitish and soft, with a huge hump on the lower back armed with two small hooks.
His enormous head is now seen to be apparently circular in outline, and we readily see how perfectly it would fill the opening of the burrow like an operculum. But a close examination shows us that this operculum is really composed of two halves, on two separate segments of the body, the segment at the extremity only being the true head, armed with its powerful, sharp, curved jaws. As he lies there sprawling on his six spider-like legs, we may now easily test the skill of his trap, and gain some idea of his voracious personality.
If with the point of our knife-blade, holding it in the direction of the insect"s body, we now touch its tail, what a display of vehement acrobatics! Instantly the agile body is bent backward in a loop, while the teeth fasten to the knife-blade with an audible click. If our finger-tip is subst.i.tuted for the steel, the force of the stroke and the p.r.i.c.k and grip of the jaws are unpleasantly perceptible.
In order to fully comprehend the make-up of this curious cave-dweller we must turn biologists for the moment. He must be considered from the evolutionary stand-point, or at least from the stand-point of comparative anatomy.
The first discovery that we make is that as we now see him he is crawling on his back--a fact which seems to have escaped his biographers heretofore. It is, in truth, the underside of his head which is uppermost at the mouth of the burrow, and his six zigzag legs are distorted backward to enable him to keep this contrary position. And what a hideous monster is this, whose flat, metallic, dirt-begrimed face stares skyward from this circular burrow! Well might it strike terror to the heart of the helpless insect which should suddenly find himself confronted by the motionless stare of these four cruel, glistening black eyes! But he is now a "fish out of water," and is about as helpless, nature never having intended him to be seen outside of his burrow--at least, in this present form. There he dwells, setting his circular trap at the mouth of his pitfall, and waiting for the voluntary sacrifice of his insect neighbors to fill his maw.
But this uncouth shape, which so courts obscurity, is not always thus so reasonably retiring. A few gla.s.s tumblers inverted above as many of these larger holes during the summer will intercept the winged sprite into which he is shortly to be transfigured--a brilliant metallic-hued beetle, perhaps flashing with bronzy gold or glittering like an emerald--the beautiful _cicindela_, or tiger-beetle, known to the entomologist as the most agile winged among the coleopterous tribe; known to the populace, perhaps, simply as a bright glittering fly that revels in the hot summer sands of the sea-sh.o.r.e or dusty country road, making its short spans of glittering flight from the very feet of the observer.
[Ill.u.s.tration]
If we capture one of them with our b.u.t.terfly-net he will be found to bear a general resemblance to the portrait here indicated--a slender-legged, proportionably large-headed beetle, with formidable jaws capable of wide extension, and re-enforced by an insatiate carnivorous hunger inherited from his former estate.
It will thus be seen that all the holes which we observe in the ground are not ant-holes; nor, indeed, are they monopolized by the tiger-beetles. There were other tunnels which I saw dug in my square yard of earth on that morning, which, while not of quite such depth, represented equally deep-laid plans.
While observing my cicindelas on that morning, my attention was at length diverted by an old friend of mine, who gave promise of much entertainment--a tiny black wasp, whose restless, rapid, zigzag, apparently aimless wanderings over the ground brought him into continual danger of contact with the s.n.a.t.c.hing jaws of the cave-dwelling tiger, from which, however, he somehow escaped, though I distinctly heard the occasional clicking of the eager jaws.
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With short abrupt flights or agile runs of a few inches, accompanied by nervous periodic flirts of the folded wings, the insect had covered pretty much of the ground in a short time, until she at length appeared to have discovered the object of her search, as she withdrew from beneath a sorrel leaf a big fat spider several times as large as herself. Its legs were folded beneath its body, and it was perfectly plain that this was not the first time that it had been in the toils of the wasp, which had evidently stung it into submission and stupor some minutes previous. Tugging bravely at her charge, the little black Amazon dragged her burden nimbly over the ground, pulling it after her in entire disregard of obstacles, now this way, now that, with the same exasperating disregard of eternity which she at first displayed, and at length deposited it on the top of a little flat weed, where it was left, while for five minutes more she pursued the same zigzag, apparently senseless meandering over the entire field of earth. Now she seems again to stumble upon her neglected prey, and taking it once more in her formidable jaws, she lugs it again for a long helter-skelter jaunt, this time depositing it in the neighborhood of a hole, which at first sight might have been considered an "ant-hole," from the debris which lay scattered about in its vicinity. After considerable needless delay, she is seen for once motionless, so far as her legs are concerned, but with her head over the tunnel, while, with flipping wings and rapidly waving antennae, she investigates its depths. Satisfied that all is well, she again reaches her drowsy spider, by a tangled circuit of about a quarter of a mile--wasp measurement--and taking the victim in her teeth for the third time, finally succeeds in reaching the burrow, into which, without a particle of ceremony, she instantly retreats, dragging her helpless burden after her. Both wasp and spider are soon out of sight, and so remain perhaps for a s.p.a.ce of two minutes, when the tips of the nervous antennae appear at the doorway and the wasp emerges.
What now follows is most curious and interesting. With an energy and directness in striking contrast to her previous proceedings, she proceeds to fill the cavity, biting the earth with her mandibles, and with her spiked legs kicking and shoving in the loose soil thus collected, ever and anon backing up to the hole and inserting the tip of her tail to force down the ma.s.s. As the filling is nearly completed, with the fore feet and jaws the surrounding earth is sc.r.a.ped for material, which she immediately proceeds to pack by a rhythmic tamping motion of the tail, until, at the end of five minutes, perhaps, the ground-level is finally reached, the surface smoothed, and no sign remains to mark the grave of the stupefied spider victim.
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Not an hour after this episode I was treated to another of even more interest. As I took my seat upon the door-step I started into flight a big black wasp, upon whose doings I had evidently been intruding.
This wasp was much larger than the one just described, being about an inch in length. Its wings were pale brown and its body jet-black, with sundry small yellowish spots about the thorax. But its most conspicuous feature, and one which would ever fix the ident.i.ty of the creature, was the long, slender, wire-like waist, occupying a quarter of the length of its entire body.
In a moment or two the wasp had returned, and stood at the mouth of the shallow pit. Eying me intently for a s.p.a.ce, and satisfied that there was nothing to fear, she dived into the hollow and began to excavate, turning round and round as she gnawed the earth at the bottom, and shovelling it out with her spiked legs. Now and then she would back out of the burrow to reconnoitre, and her alert att.i.tude at such times was very amusing--her antennae drooping towards the burrow and in incessant motion; the abdomen on its long wire stem bobbing up and down at regular intervals, accompanied by a flipping motion of the wings; the short fore legs, one or both, upraised with comical effect.
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As the tunnel was deepened a new method of excavation was employed. It has now reached a depth of an inch, only the extremity of the insect"s body appearing, and the two hindermost legs clinging to surrounding earth for purchase. The deep digging is now accompanied by a continual buzzing noise, resembling that produced by a bluebottle fly held captive between one"s fingers. At intervals of about ten or fifteen seconds the wasp would quickly back out of the burrow, bringing a load of sand, which it held between the back of the jaws and its thorax, sustained at the sides by the two upraised fore legs. After a moment"s pause with this burden, the insect would make a sudden short darting flight of a foot or more in a quick circuit, hurling the sand a yard or more distant from the burrow. At the end of about fifteen minutes the burrow was sunk to the depth of an inch and a half, the wasp entirely disappearing, and indicated only by the continuous buzzing.
At this time, the luncheon hour having arrived, I was obliged to pause in my investigations, and in order to be able to locate the burrow in the event of its obliteration by the wasp before my return, I scratched a circle in the hard dirt, the hole being at its exact centre.
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Upon my return, an hour later, I was met with a surprise. The ways of the digger-wasps of various species were familiar, but I now noted a feature of wasp-engineering which indeed seems to await its chronicler, as I find no mention of it by the wasp-historians.
At the exact centre of my circle, in place of a cavity, I now found a tiny pile of stones, supported upon a small stick and fragment of leaf, which had been first drawn across the opening.
This was evidently a mere temporary protection of the burrow, I reasoned, while the digger had departed in search of prey, and my surmise was soon proved to be correct, as I observed the wasp, with bobbing abdomen and flipping wings, zigzagging about the vicinity.
Presently disappearing beneath a small plantain leaf, she quickly emerged, drawing behind her not a spider, as in the case of her smaller predecessor, but a big green caterpillar, nearly double her own length, and as large around as a slate-pencil--a peculiar, pungent, waspy-scented species of "puss-moth" larva, which is found on the elm, and with which I chanced to be familiar.
The victim being now ready for burial, the wasp s.e.xton proceeded to open the tomb. Seizing one stone after another in her widely opened jaws, they were scattered right and left, when, with apparent ease and prompt despatch, the listless larva was drawn towards the burrow, into whose depths he soon disappeared. Then, after a short and suggestive interval, followed the emergence of the wasp, and the prompt filling in of the requisite earth to level the cavity, much as already described, after which the wasp took wing and disappeared, presumably bent upon a repet.i.tion of the performance elsewhere. But she had not simply buried this caterpillar victim, nor was the caterpillar dead, for these wasp cemeteries are, in truth, living tombs, whose apparently dead inmates are simply sleeping, narcotized by the venom of the wasp sting, and thus designed to afford fresh living food for the young wasp grub, into whose voracious care they are committed.
By inserting my knife-blade deep into the soil in the neighborhood of this burrow I readily unearthed the buried caterpillar, and disclosed the ominous egg of the wasp firmly imbedded in its body. The hungry larva which hatches from this egg soon reaches maturity upon the all-sufficient food thus stored, and before many weeks is transformed to the full-fledged, long-waisted wasp like its parent.
The disproportion in the sizes of the predatory wasps and their insect prey is indeed astonishing. The great sand-hornet selects for its most frequent victim the buzzing cicada, or harvest-fly, an insect much larger than itself, and which it carries off to its long sand tunnels by short flights from successive elevated points, such as the limbs of trees and summits of rocks, to which it repeatedly lugs its clumsy prey.
In the present instance the contrast between the slight body of the wasp and the plump dimensions of the caterpillar was even more marked, and I determined to ascertain the proportionate weight of victor and victim.
Constructing a tiny pair of balances with a dead gra.s.s stalk, thread, and two disks of paper, I weighed the wasp, using small square pieces of paper of equal size as my weights. I found that the wasp exactly balanced four of the pieces. Removing the wasp and subst.i.tuting the caterpillar, I proceeded to add piece after piece of the paper squares until I had reached a total of twenty-eight, or seven times the number required by the wasp, before the scales balanced. Similar experiments with the tiny black wasp and its spider victim showed precisely the same proportion, and the ratio was once increased eight to one in the instance of another species of slender orange-and-black-bodied digger which I subsequently found tugging its caterpillar prey upon my door-step patch.
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The peculiar feature of the piling of stones above the completed burrow was not a mere individual accomplishment of my wire-waisted wasp. On several occasions since I have observed the same manoeuvre, which is doubtless the regular procedure with this and other species. The smaller orange-spotted wasp just alluded to indicated to me the location of her den by pausing suggestively in front of a tiny cairn. In this instance a small flat stone, considerably larger than the tunnel, had been laid over the opening, and the others piled upon it. On two occasions I have surprised this same species of wasp industriously engaged in the selection of a suitable flat foundation-stone with which to cover her burrow: her widely extended slender jaws enable her to grasp a pebble nearly a third of an inch in width.