Natural Acts

by David Quammen

  There was also the mystery of its evolution. Where had C. eustrigata come from? How had the bloodsucking adaptation, along with the equipment to practice it, arisen? What were the intermediate stages between Bänziger’s new species and those other Lepidoptera—all 149,999 of them—who noodle from blossom to blossom drinking nectar through their elongated schnosters? What manner of temptation could have lured certain moth species astray, turning their tastes from flowers to blood?

  The answer, it seems, was fruit. Faced with mortal competition over limited supplies of nectar, a number of noctuid species have adapted themselves to feeding on the juices of overripe fruit. Some have developed stronger and sharper mouth tubes that allow them to pierce the skin of soft fruits, such as peaches and raspberries, and suck out their fill of juice. One species is even armed with a proboscis that will penetrate the skin of an orange. Among these fruit-piercing moths are several close cousins of C. eustrigata. Bänziger suggests that in a habitat where fruit was available only seasonally but juicy mammals were present year-round, desperate necessity might have led to the next logical step: vampirism, as practiced by moths.

  But the vampire moth was just a distraction from what had taken Hans Bänziger out to Southeast Asia. He was there to study a group of species he called, rather blandly, the “eye-frequenting” Lepidoptera—moths that literally live on a diet of tears.

  These wondrous creatures may have evolved from the opportunistic blood-drinkers that clean up after messy mosquitoes. Bänziger says: “Probably by crawling about on their mammalian hosts some moths found the eyes, where there are always discharges. And thus there evolved the habit of dining exclusively upon eye discharges, which contain various proteins such as globulin, albumen, and others in the leucocytes and epithelial cells in tears.” Such moths, in the wild, would drink from the eyes of elephants. They would drink from the eyes of horses, buffalo, antelope, or pigs. And as Bänziger demonstrated with his characteristic élan, given a proper opportunity, they would drink from the eyes of man. “The lachrymal secretion was very much stimulated by the activity of the moth. After 30 min. my eye was so irritated that I was forced to interrupt the experiment.” Only thirty minutes of moth-in-eye jabbing, imagine, and he called a halt. But not before the insect had drunk freely from Bänziger’s own tears of—joy! There is even a photograph showing a small noctuid of the species Lobocraspis griseifusa perched head-down across Bänziger’s brow, its tube extended to drink fluid off the surface of his cornea. “Note the deep penetration,” reads his unblinking caption, “of the proboscis between eye and eye lid.”

  Note the deep penetration of Lepidoptera between fact and imagination. I suspect that the Greeks and the Romans would have known what to make of Lobocraspis griseifusa, a species in the spiritual tradition. Imagine how Ovid would have loved those insects. The souls of the dead return, on powdered wings and in silence, to comfort mankind; to console us earthbound survivors; to drink away our very tears

  It’s a nice thought—too nice to be true. But the intricate realities of evolutionary entomology don’t lend themselves so well (no better than other branches of nature) to our neat romances and our pathetic fallacies, and these two species stand as vouchers to that truth. If we idealize the tear-drinkers, then what about the suckers of blood? A moth, hungry animal, is only what it is.

  Rumors of a Snake

  WHAT THE WORLD NEEDS IS A GIANT SNAKE. Make it vicious, make it loathsome, make it sixty feet long—and let it swim in the waters of the Amazon.

  All right, don’t look at me, this isn’t my personal obsession. Apparently there exists a popular imperative to that effect, a deep-seated hope or dark desire, issuing from the delicately balanced ecosystem of collective human consciousness. Give us a huge snake. A serpentine monster at the far fringe of imaginability. Let it inhabit the wettest mires of the deepest jungle. A horrific thing, slithering along in elegant menace, belly distended with pigs and missing children. The evidence for this weird yearning is oblique but cogent: Lacking any such beast, we are eager to settle for rumors of one. Otherwise how to explain the breathless compoundment of hearsay, tall tale, and hyperbole that has always surrounded Eunectes murinus, an honest and tangible animal commonly called the anaconda?

  One fair example appears in the memoirs of Colonel Percy Fawcett, a British archeologist and explorer of the early twentieth century. In 1906, Fawcett was sent out from London by the Royal Geographical Society to make a survey along certain rivers in western Brazil. “The manager at Yorongas told me he killed an anaconda 58 feet long in the Lower Amazon. I was inclined to look on this as an exaggeration at the time, but later, as I shall tell, we shot one even larger than that.” The disclaimer about “I was inclined…” is a cagey stroke. Major Fawcett would have us take him for a hardheaded British skeptic.

  Later he tells: “We were drifting easily along in the sluggish current not far below the confluence of the Rio Negro when almost under the bow of the igarité there appeared a triangular head and several feet of undulating body. It was a giant anaconda. I sprang for my rifle as the creature began to make its way up the bank, and hardly waiting to aim smashed a .44 soft-nosed bullet into its spine, ten feet below the wicked head.…We stepped ashore and approached the reptile with caution. It was out of action, but shivers ran up and down the body like puffs of wind on a mountain tarn. As far as it was possible to measure, a length of forty-five feet lay out of the water, and seventeen feet in it, making a total length of sixty-two feet.” The indisputable logic of good arithmetic. It might all be true but most likely it isn’t.

  An adventurer of the 1920s named F. W. Up de Graff offered a similar account, having observed his anaconda in shallow water: “It measured fifty feet for certainty, and probably nearer sixty. This I know from the position in which it lay. Our canoe was a twenty-four footer; the snake’s head was ten or twelve feet beyond the bow; its tail was a good four feet beyond the stern; the center of its body was looped up into a huge S, whose length was the length of our dugout and whose breadth was a good five feet.” But size estimates made in a watery medium are notoriously unreliable—especially when that watery medium is the Amazon River.

  Bernard Heuvelmans, in his feverish book of cryptozoology, On the Track of Unknown Animals, tells at third or fourth hand of another Brazilian specimen that was purportedly killed in 1948: “The snake, which was said to measure 115 feet in length, crawled ashore and hid in the old fortifications of Fort Tabatinga on the River Oiapoc in the Guaporé territory. It needed 500 machine-gun bullets to put paid to it. The speed with which bodies decompose in the tropics and the fact that its skin was of no commercial value may explain why it was pushed back in the stream at once.” Always for the gigantic individuals there is this absence of physical evidence, and always a waterproof reason for the absence: no cameras on hand, rotting meat, even the skin was too heavy to carry out. One photograph did exist that, during the 1950s, was sold all over Brazil as a postcard, its caption claiming a length of 131 feet for the snake pictured. Unfortunately, no object of reference appeared in the photo with it. That snake might as easily have been a robust but minuscule 20-footer.

  My own modest sighting comes not from Brazil but from northeastern Ecuador, along the Rio Aguarico, in a remote zone of lowland jungle that may be as favorable to the production and growth of anacondas as almost anywhere in the Amazon drainage. Like those other wide-eyed witnesses Fawcett and Up de Graff, I was in a dugout canoe, along with a dozen or so adventuresome tourists. Our guide was an intrepid and jungle-smart young man named Randy Borman, raised there in the forest among Cofane Indians. Randy spotted the big snake on a log tangle near the riverbank while the rest of us were gawking elsewhere. He steered the boat in for a closer look.

  Dark gunmetal gray with sides mottled in reddish brown, the anaconda was sunning itself placidly. Barely above the water on a low-riding log; protectively colored and patterned so that even from ten yards away it was virtually invisible. Randy edged the canoe closer
. Do you see it now? Some of us did; several admitted they didn’t. We moved closer. Here indeed was a formidable snake. Still motionless, still sunbathing dreamily. I was delighted with this glimpse of an anaconda in the wild, but—amid the soft brushfire crackle of camera shutters—we had already ventured closer than I ever expected to get. Then closer still. A very tolerant and self-possessed snake. Beautiful big head. Thick graceful coils of body. Sizable brown eye. Hello, Randy? Just when I thought our guide would back the canoe off, instead he dove over the gunnel to grab this creature around the neck.

  It was a deeply startling act. But Randy came up again, deftly, with a great armload of anaconda wrapping itself onto him in surprise and anger, squeezing with the authority of a species that does its killing by constriction. My face bore the contemplative expression of two eggs sunnyside in a white Teflon skillet.

  Randy smiled calmly. “We’ll take him back to camp for the others to see.” An hour later, having been much fawned over and photographed, the animal was gently released back into its river. A few fast pulses of undulant swimming, then a dive beneath the brown water, and it was gone. There was a convenient absence of physical evidence.

  So in recounting the story afterward (which I have not hesitated to do often, cornering people at parties and hoping the talk might turn to giant reptiles), I could make that poor snake any damn size I pleased. A piddling ten feet? Maybe eleven? Roughly the same girth as a man’s biceps? In fact (so I would say, with coy dismissiveness) it was rather dainty as this species goes. Still, an impressive beast.

  Very little is known about the biology of Eunectes murinus, the anaconda; even less about its life history in the wild; and a sad fact is that no one seems much to care.* Not a single field-research project, one expert has told me, is currently being done on it. The species has not yet found its George Schaller, its Dian Fossey, its Jane Goodall.

  We know that it is a nonvenomous constrictor of the boa family. We know that it is aquatic, preferring slow rivers and swamps. That it bears live young (as opposed to laying eggs) in litters of up to eighty. That it is native to tropical South America east of the Andes, and also to the island of Trinidad. We know that (unlike other boas and pythons) it does poorly and often dies soon in captivity. But as to the rest, its favored diet, its daily and seasonal rhythms, its mating and birthing behavior, physiology, growth rate, longevity: almost a total blank. There is an absence of evidence.

  Admittedly, the prospect of studying full-grown anacondas in their own habitat offers an array of uniquely forbidding logistical problems. For that reason or whatever others, scientific consideration of Eunectes murinus has been limited almost entirely to the same simple question that so mesmerized those early explorers: How big does it get? Well, really quite big. Bigger than any other snake on Earth. But how big is that?

  A second sad fact about the anaconda: By scientific standards of verification, it just doesn’t seem to be nearly so large as everyone seems to want to believe it is. Forget 131 feet. Forget 62 feet, even with faultless arithmetic. Discount the record-length skins, which generally have been stretched by a good 20 percent in the process of tanning. Scientists have their own unstretchable views on this matter.

  One respected herpetologist, Afrânio do Amaral, has posited a maximum length for the anaconda of about 42 feet. But then Afrânio do Amaral is a Brazilian, arguably with a vested patriotic interest. And after him the figures only get stingier. James A. Oliver of the American Museum of Natural History was willing to grant 371/2 feet, based on the measurement made by a petroleum geologist, with a surveyor’s tape, of a snake shot along the Orinoco River. But again in this case there was the problem of physical evidence: “When they returned to skin it, the reptile was gone,” we are told. “Evidently it had recovered enough to crawl away.” Teddy Roosevelt is said to have offered $5,000 for a skin or skeleton 30 feet long, and the money was never claimed.* Sherman and Madge Minton, the authors of several reliable snake books, declare: “To the best of our knowledge, no anaconda over twenty-five feet long has ever reached a zoo or museum in the United States or Europe.” And Raymond Ditmars, an eminent snake man at the Bronx Zoo early in this century, wouldn’t believe anything over 19 feet.

  Can these people all be discussing the same animal? Can Ditmars’s parsimonious 19 feet be reconciled with the eyewitness account of Major Fawcett? Does Roosevelt’s unclaimed cash square with Heuvelmans’s 115 feet of worthless decaying snakeflesh? It seems impossible.

  But new evidence has lately reached me that suggests an explanation for everything. The evidence is a small color photograph. The explanation is relativity.

  Not Einstein’s variety, but a similar sort, which I’ll call Amazonian relativity. It’s very simple: The true genuine size of an anaconda (this theory applies also to piranha and bird-eating spiders) is relative to three other factors: 1) whether or not the snake is alive; 2) how close you yourself are to it; and 3) how close both of you are, at that particular moment, to the Amazon heartland. A live snake is always bigger than a dead one, even allowing for posthumous stretch. And as the other two distances decrease—from you to the snake, and from you to the Amazon—the snake varies inversely toward humongousness.

  This small color photograph, of such crucial scientific significance, arrived in the mail from an affable Dutch-born engineer, a good fellow I met on that Rio Aguarico trip. Unlike me, he had carried a camera, and sending the print was meant as a favor. In the photo’s foreground I can see the outline of my own dopey duck-billed hat. The background is a solid wall of green jungle. At the center of focus is Randy Borman, astride the stern of his dugout, holding an anaconda. Dark gunmetal gray with sides mottled in reddish brown.

  The snake is almost as big around as his wrist. It might be five feet long. Possibly close to six. But photographs can be faked. I don’t believe this one for a minute.

  Wool of Bat

  FROM PLINY TO SHAKESPEARE to Tom McGuane, there has been a consensus: Any creatures so grotesquely improbable as bats must perforce lend themselves to some grotesquely improbable human use. The logic may be dubious, but the notion is long-standing.

  During the first century A.D., for instance, Gaius Plinius Secundus (that is, Pliny the Elder) suggested in his Natural History that a drop of bat’s blood hidden beneath a woman’s pillow would affect her as an aphrodisiac. Twelve centuries later, Albertus Magnus claimed that smearing bat blood over your face like Coppertone would improve night vision. Macbeth’s three witches, of course, are responsible for that famous stew recipe of which the partial ingredients are

  Eye of newt, and toe of frog,

  Wool of bat, and tongue of dog.

  An early colonial writer named John Lawson claimed that Indian children in North Carolina were often cured of a craving to eat dirt by feeding them roast bat on a skewer (though Lawson doesn’t say whether feeding dirt to adults might possibly cure their urge to roast a bat and make a child eat it). More recently, McGuane’s raucous comedic novel The Bushwhacked Piano describes the scheme of a certain C. J. Clovis, former fat man and one-legged con artist, to contract with mosquito-plagued municipalities for the erection of bat towers—each fully stocked with 1,500 bats dyed Day-Glo orange—for solving the local bug problem. The bats would devour the mosquitoes, theoretically, while the cheerful dye allowed citizens to watch their investment in action. And the fictional C. J. Clovis (as McGuane himself probably knew) is but an echo of historical actuality: During the 1920s, a Dr. Charles Campbell, of San Antonio, proposed “municipal bat roosts” to control mosquitoes and thereby reduce malaria in the American South. At least one of those Campbell-style roosts was built, on Sugarloaf Key in Florida, by Mr. Richter C. Perky, who ran a fishing camp. Although accounts differ as to whether Perky ever actually stocked his tower with imported bats or merely baited it to attract the native ones, orange Day-Glo dye can safely be ruled out. But wait. Even this isn’t all.

  Practical bats have just hit the news again. A recent report in American
Heritage magazine reveals that the United States government, during World War II, had a plan to use Mexican free-tailed bats for firebombing Japan.

  The idea was to refrigerate these bats into hibernation, see, fit each with a small payload of napalm and a little-bitty parachute, see, drop thousands like that from planes over Japanese cities, see, and hope for the best. No I’m not making this up. Your government. The research cost $2 million.

  Clearly the bat has captured human imaginations, and that may be because it seems triply oxymoronic: a flying mammal that sees in the dark by listening to its own silent screams. It is in truth an extraordinary animal, equipped with some startlingly sophisticated evolutionary adaptations and represented around the world by a wide variety of different forms. If the bat is grotesquely improbable, so is Pablo Picasso.

  Chiroptera is the collective name for this order of mammals, and the main defining characters are familiar: wings formed by thin flaps of skin stretched between hugely elongated fingers; the habit of feeding by night and resting by day; hind feet that lock closed automatically when suspending the body’s weight upside down; and a system of echolocation (at least among the Microchiroptera, one of two suborders), whereby the bat uses varying echoes from its own ultrasonic calls to find prey and steer itself through darkness. Anyone who has ever sat on a suburban porch while summer twilight faded has seen evidence of that last feature’s uncanny efficiency. The erratic diving and swerving and swooping of those small black shapes reflect feeding success, not confusion. Their brains process the echo data at rates unimaginable to us—though some researchers on the human brain have been eagerly studying how they do it—so that a cruising and squeaking bat, while avoiding an array of tricky obstacles, can catch one third its own weight in flying insects within half an hour. Furthermore, they may have developed this sonar as much as 50 million years before we reinvented it.