« ZurückWeiter »
THE ATTAS AT HOME
BY WILLIAM BEEBE
CLAMBERING through white, pasty mud, which stuck to our boots by the pound; peering through bitter, cold mist, which seemed but a thinner skim of mud; drenched by flurries of icy drops shaken from the atmosphere by a passing moan and a crash; breathing air heavy with a sweet, horrible, penetrating odor such was the world as it existed for an hour one night, while the Commandant of Douaumont and I wandered about, completely lost, on the top of his own fort. We finally stumbled on the little grated opening through which the lookout peered unceasingly over the landscape of mud. The mist lifted and we rediscovered the cave-like entrance, watched for a moment the ominous golden dumb-bells rising from the première ligne, scraped our boots on a German helmet, and went down again into the strangest sanctuary on earth.
This was the vision that flashed through my mind as I began vigil at an enormous nest of Attas the leaf-cutting ants of the British Guiana jungle. In front of me was a glade, about thirty feet across, devoid of green growth and filled with a great irregular expanse of earth and mud. Relative to the height of the Attas, my six feet must seem a good half-mile, and from this height I looked down and saw again the same inconceivably sticky clay of France. There were the rain-washed gullies, the half-roofed entrances to the vast underground fortresses, clean-swept, perfect roads, as efficient as the arteries of Ver
dun; flapping dead leaves like the omnipresent, worn-out scarecrows of camouflage. And over in one corner, to complete the simile, were a dozen shellholes, the homes of voracious ant-lions, which, for passing insects, were unexploded mines, set at hair-trigger.
My Atta city was only two hundred feet away from the laboratory, in fairly high jungle, within sound of the dinner triangle, and of the lapping waves on the Mazaruni shore. To sit near by and concentrate solely upon the doings of these ant-people was as easy as watching a single circus ring of performing elephants, while two more rings, a maze of trapezes, a race-track, and sideshows were in full swing. The jungle around me teemed with interesting happenings and distracting sights and sounds. The very last time I visited the nest, and became absorbed in a line of incoming ants, I heard the shrill squeaking of an angry hummingbird overhead. I looked up, and there, ten feet above, was a furry tamandua anteater slowly climbing a straight purpleheart trunk, while round and round his head buzzed and swore the little fury
a pinch of cinnamon feathers, ablaze with rage. The curved claws of the unheeding ant-eater fitted around the trunk, and the strong prehensile tail flattened against the bark, so that the creature seemed to put forth no more exertion than if walking along a fallen log. Now and then it stopped and daintily picked at a bit of termite nest.
With such side-shows it was sometimes difficult to concentrate on the Attas. Yet they offer problems for years of study. The glade was a little world in itself, with visitors and tenants, comedy and tragedy, sounds and silences. It was an ant-made glade, with all new growths choked either by upflung, earthen hillocks, or by leaves bitten off as soon as they appeared. The casual visitors were the most conspicuous: an occasional trogon swooping across a flashing, feathered comet of emerald, azurite, and gold. Or, slowly drifting in and out among the vines, and coming to rest with waving wings, a yellow-and-red-spotted Ithomiid-or was it a Heliconiid or a Danaiid? with such bewildering models and marvelous mimics it was impossible to tell without capture and close examination. Giant purple tarantula-hawks hummed past, scanning the leaves for their prey.
Another class of glade-haunters were those who came strictly on businessplasterers and sculptors, who found wet clay ready to their needs. Great golden and rufous bees blundered down and tore off bucketsful of mud; while slender-bodied, dainty wasps of ebony, after much fastidious picking of place, would detach a tiny bit of the whitest clay, place it in their snuff-box holder, clean their feet and antennæ, run their rapier in and out, and delicately take to wing. Little black trigonid bees had their special quarry a small deep valley, in the midst of a waste of interlacing Bad Lands, on the side of a precipitous butte. Here they cut and gouged to their hearts' content, plastering the thighs until their wings would hardly lift them. They braced their feet, whirred, lifted unevenly, and sank back with a jar; then, turning, bit off a piece of ballast, and heaving it over the precipice, swung off on an even keel.
Close examination of some of the craters and volcano-like cones revealed
many species of ants, beetles, and roaches searching for bits of food - the scavengers of this small world. But the most interesting were the actual parasites, flies of many colors and sizes, humming past like little planes and Zeppelins over this hidden city, ready to drop a bomb in the form of an egg deposited on the refuse-heaps or on the ants themselves. The explosion might come slowly, but it would be none the less deadly. Once I detected a hint of the complexity of glade life - beautiful metallic green flies walking swiftly about on long legs, searching nervously, whose eggs would be deposited near those of other flies, their larvæ to feed upon the others parasites upon parasites.
As I had resolutely put the doings of the tree-tops away from my consciousness, so now I forgot visitors and parasites, and armed myself for the excavation of this buried metropolis. I rubbed vaseline on my high boots, and about the tops bound a band of teased-out absorbent cotton. My pick and shovel I treated likewise, and thus I was comparatively insulated; for without precautions no living being could withstand the slow, implacable attack of disturbed Attas. At present I walked unmolested across the glade. The millions beneath my feet were as unconscious of my presence as they were of the breeze in the palm-fronds overhead.
At the first deep shovel-thrust, a slow-moving flood of reddish-brown began to pour forth from the crumbled earth - the outposts of the Atta Maxims moving upward to the attack. For a few seconds only workers of various sizes appeared; then an enormous head heaved upward, and there came into the light of day the first Atta soldier. He was twice the size of a large worker and heavy in proportion. Instead of being drawn up into two spines, the top of his head was rounded, bald, and shiny, and only at the back were the
two spines visible, shifted downward. The front of the head was thickly clothed with golden hair, which hung down bang-like over a round, glistening single median eye. One by one, and then shoulder to shoulder, these Cyclopean Maxims lumbered forth to battle, and soon my boots were covered in spite of the grease, all sinking their mandibles deep into the leather.
When I unpacked these boots this year, I found the heads and jaws of two Attas still firmly attached, relics of some forgotten foray of the preceding year. This mechanical, vise-like grip, wholly independent of life or death, is utilized by the Guiana Indians. In place of stitching up extensive wounds, a number of these giant Atta Maxims are collected, and their jaws applied to the edges of the skin, which are drawn together. The ants take hold, their bodies are snipped off, and the row of heads remains until the wound is healed.
Over and around the outpouring soldiers, the tiny workers ran and bit and chewed away at whatever they could reach. Dozens of ants made their way up to the cotton, but found the utmost difficulty in clambering over the loose fluff. Now and then, however, a needlelike nip at the back of my neck showed that some pioneer of these shock troops had broken through, when I was thankful that Attas could only bite, and not sting as well. At such a time as this, the greatest difference is apparent between these and the Eciton army ants. The Eciton soldier, with his long curved scimitars and his swift, nervous movements, was, to one of these great insects, as a fighting d'Artagnan would be to an armored tank. The result was much the same, however perfect efficiency.
I now dug swiftly and crashed with pick down through three feet of soil. The great entrance arteries of the nest
branched and bifurcated, separated and anastomosed, while here and there were chambers varying in size from a cocoanut to a football. These were filled with what looked like soft grayish sponge covered with whitish mould, and these sombre affairs were the raison d'être of all the leaf-cutting, the trails, the struggles through jungles, the constant battling against wind and rain and sun.
But the labors of the Attas are renewed only when a worker disappears down a hole with his hard-earned bit of leaf. He drops it and goes on his way. We do not know what this way is, but my guess is that he turns around and goes after another leaf. Whatever the nests of Attas possess, they are without recreation-rooms. These sluggardinstructors do not know enough to take a vacation; their faces are made for biting, not for laughing or yawning. I once dabbed fifteen Mediums with a touch of white paint as they approached the nest, and within five minutes thirteen of them had emerged and started on the back track again.
The leaf is taken in charge by another Medium, hosts of whom are everywhere. Once, after a spadeful, I placed my eye as close as possible to a small heap of green leaves, and around one oblong bit were five Mediums, each with a considerable amount of chewed and mumbled tissue in front of him. This is the only time I have ever succeeded in finding these ants actually at this work. The leaves are chewed thoroughly, and built up into the sponge gardens, being used neither for thatch, nor for food, but as fertilizer. And not for any strange subterranean berry or kernel or fruit, but for a fungus or mushroom. The spores sprout and proliferate rapidly, the gray mycelia covering the garden; and at the end of each thread is a little knobbed body filled with liquid. This forms the sole food of the
ants in the nest; but a drop of honey placed by a busy trail will draw a circle of workers at any time- both Mediums and Minims, who surround it and drink their fill.
When the fungus garden is in full growth, the nest-labors of the Minims begin; and until the knobbed bodies are actually ripe, they never cease to weed and, to prune, killing off the multitude of other fungi and foreign organisms, and, by pruning, to keep their particular fungus growing, and prevent it from fructifying. The fungus of the Áttas is a particular species, with the resonant, Dunsanesque name of Rozites gongylophora. It is quite unknown outside of the nests of these ants, and is as artificial as a banana.
Only in Calcutta bazaars at night, and in underground streets of Peking have I seen stranger beings than I unearthed in my Atta nest. Now and then there rolled out of a shovelful of earth an unbelievably big and rotund cicada larva - which, in the course of time, whether in one or in seventeen years, would emerge as the great marbled, winged Cicada gigas, spreading five inches from tip to tip. Small tarantulas, with beautiful wine-colored cephalothorax, made their home deep in the nest, guarded, perhaps, by their dense covering of hair. Slender scorpions sidled out from the ruins; they were bare, with vulnerable joints, but they had the advantage of long, mobile arms, and a pair of hands which could quickly and skillfully pluck an attacking ant from any part of their anatomy.
The strangest of all the tenants were the tiny, amber-colored roaches, which clung frantically to the heads of the great soldier ants, or scurried over the tumultuous mounds, searching for a crevice sanctuary. They were funny,
fat little beings, wholly blind, yet supremely conscious of the danger that threatened, and with only the single thought of getting below the surface as quickly as possible. The Attas have very few insect guests, but this cockroach is one who has made himself perfectly at home. Through century upon century he has become more and more specialized and adapted to Atta life, eyes slipping until they are no more than faint specks, legs and antennæ changing, gait becoming altered to whatever speed and carriage best suits little guests in big underground halls and galleries.
He and his race have evolved unseen and unnoticed even by the Maxim policemen. But when nineteen hundred humanly historical years have passed, a man with a keen sense of fitness named him Little Friend of the Attas; and so for a few years more, until we scientists give place to the next caste, Attaphila will, all unconsciously, bear a name.
Attaphilas have staked their whole gamble of existence on the continued possibility of guestship with the Attas. Although they live near the fungus gardens, they do not feed upon them, but gather secretions from the armored skin of the giant soldiers, who apparently do not object, and show no hostility to their diminutive masseurs. A summer-boarder may be quite at home on a farm, and safe from all ordinary dangers; but he must keep out of the way of scythes and sickles, if he chooses to haunt the hayfields. And so Attaphila, snug and safe, deep in the heart of the nest, has to keep on the qui vive when the ant-harvesters come to glean in the fungus gardens. Snip, snip, snip, on all sides in the musty darkness, the keen mandibles shear the edible heads; and though the little Attaphilas dodge and run, yet most of them, in course of time, lose part of an antenna, or even a whole one.
Thus the Little Friend of the Leafcutters lives easily through his term of weeks or months, or perhaps even a year, and has nothing to fear for food or mates, or from enemies. But Attaphilas cannot all live in a single nest, and there must come a crisis, when they pass out into a strange world of terrible light and multitudes of foes. For these pampered, degenerate roaches to find another Atta nest unaided, would be inconceivable. In the big nest that I excavated I observed them on the backs and heads, not only of the large soldiers, but also of the queens, which swarmed in one portion of the galleries; and, indeed, of twelve queens, seven had roaches clinging to them. This has been noted also of a Brazilian species, and we suddenly realize what splendid sports these humble insects are. They resolutely prepare for their gamble, l'aventure magnifique, - the slenderest fighting chance, and we are almost inclined to forget the irresponsible implacability of instinct, and cheer the little fellows for lining up on this forlorn hope. When the time comes, the queens leave, and are off up into the unheard-of sky, as if an earthworm should soar with eagle's feathers; past the gauntlet of voracious flycatchers and hawklets, to the millionth chance of meeting an acceptable male of the same species. After the mating comes the solitary search for a suitable site; and only when the pitifully unfair gamble has been won by a single fortunate queen does the Attaphila climb tremblingly down and accept what fate has sent. His ninety-and-nine fellows have met death in almost as many ways.
With the exception of these strange inmates there are very few tenants or guests in the nests of the Attas. Unlike the termites and Eciton, who harbor a host of weird boarders, the leaf-cutters are able to keep their nest free from undesirables.
Once, far down in the nest, I came upon three young queens, recently emerged, dazed and stupid, with wings dull and glazed, who crawled with awkward haste back into darkness. And again twelve winged females were grouped in one small chamber, restless and confused. confused. This was the only glimpse I ever had of Atta royalty at home.
Good fortune was with me, however, on a memorable fifth of May, when returning from a monkey-hunt in high jungle. As I came out into the edge of a clearing, a low humming attracted my attention. It was ventriloquial, and my ear refused to trace it. It sounded exactly like a great aerodrome far in the distance, with a score or more of planes tuning up. I chanced to see a large bee-like insect rising through the branches, and following back along its path, I suddenly perceived the rarest of sights- an Atta nest-entrance boiling with the excitement of a flight of winged kings and queens. So engrossed were the ants that they paid no attention to me, and I was able to creep up close and kneel within two feet of the hole. The main nest was twenty feet away, and this was a special exit made for the occasion - a triumphal gateway erected far away from the humdrum leaftraffic.
The two-inch arched hole led obliquely down into darkness, while brilliant sunshine illumined the earthen takeoff and the surrounding mass of pink Mazaruni primroses. Up this corridor Atta nobility was coming, slowly, with dignity, as befitted the occasion. The males were more active, as they were smaller in size than the females, but they were veritable giants in comparison with the workers. The queens seemed like beings of another race, with their great bowed thorax supporting the folded wings, heads correspondingly large, with less jaw-development, but greatly increased keenness of vision.