Natural Acts

by David Quammen

  Or at least some of them. After thirty or forty she may stop, and the rest of the spiderlings will go off to face all the other obstacles, including starvation, between them and adulthood.

  The behavioral ecology of Latrodectus mactans has been studied that far, but not much farther. Even the scientists, even the arachnologists, are still puzzled; and their puzzlement is our ignorance. Does the maternal black widow perceive some conscious or unconscious signal about how many young spiders might be expected to survive? We don’t know. Is the male widow sexually capable of servicing more than one female? We don’t know. Does the possibility of his fathering further broods influence his first mate in her choice of whether or not to kill him? We don’t know. And the female, with her edgy perceptions of hunger, her hair-trigger readiness to cannibalize—has she been programmed by evolution to damper fluctuations in the population of her species? It seems plausible. But we don’t know.

  There’s a welter of uncertainties. If the female black widow wore a red question mark on her abdomen instead of an hourglass, she could scarcely better exemplify the limitations of our understanding of this—and many other—familiar but neglected aspects of the natural world. Who knows what graceful intricacies lurk in the behavioral wiring of Latrodectus mactans? Not us. Maybe that’s why she seems so spooky, so necessary, and so beautiful.

  The Troubled Gaze of the Octopus

  IN GRAVITY’S RAINBOW, Thomas Pynchon’s great steaming slag heap of a novel, there is a memorable scene in which an enormous octopus comes slouching out of the sea, grabs a young woman around the waist with one sucker-studded arm, and tries to drag her back into the water. Echoes of King Kong and Fay Wray. The woman is rescued by Pynchon’s hero, a certain Tyrone Slothrop, who pummels the octopus over the head with a wine bottle, to no effect, and then distracts it by offering a tasty crab. “In their brief time together Slothrop forms the impression that this octopus is not in good mental health,” Pynchon tells us. I have sometimes had the same feeling about Thomas Pynchon, but never mind. The point of recalling that octopus scene in particular is that I always took it to be luridly and outlandishly surreal, another hallucinatory cartoon caper, like so much that comes out of Mr. Pynchon’s rich and febrile imagination.

  It turns out, though, that I was unduly skeptical. It turns out that this scene might contain more truth than poetry. The details of anatomy and scale and behavior have a sound basis in zoological reality; only the matter of motivation remains unsettled. The species in question is Octopus dofleini, otherwise known as the giant Pacific octopus.

  Does this creature really lay hold, in such peremptory manner, of unsuspecting human beachgoers? And if so, just what has it got in mind?

  The concept of mind is not inappropriate as applied to the octopuses, since these creatures have by far the most highly developed brain in their province of the animal kingdom. They belong to the phylum Mollusca, a large group of invertebrates mainly characterized by soft bodies, hard shells, and rather primitive patterns of anatomical organization, well suited to surviving inconspicuously on the sea bottom. Typical of the Mollusca are clams, oysters, snails; the octopuses (and to a lesser extent their near relatives, the squids) are decidedly untypical. They are an evolutionary anomaly, a class of hyperintelligent misfits who have advanced far beyond their origins.

  The octopuses have an elaborate fourteen-lobed brain, an organ so large that their brain-to-body ratio exceeds that for most fishes and reptiles. Mentally, they are more on a level with birds and mammals. They possess a capacity for learning, memory, and considered behavior that makes them the smartest of all sea-dwelling animals, with the exception of marine mammals. In a laboratory, they tend to be good at mazes and perform well in tests of discrimination among visual symbols. This last talent depends partly on their acute eyesight. Every octopus looks out at the world through a pair of extraordinary eyes—eyes about which, to a human, there is something unexpectedly and disquietingly familiar.

  “The animal has eyes that stare back,” according to Martin J. Wells, a British zoologist who is one of the world’s experts in octopus physiology and behavior. “It responds to movement, cowering if anything large approaches it, or leaning forward in an alert and interested manner to examine small happenings in its visual field.” Jacques Cousteau goes a bit further: “When a diver sees a giant octopus in the dim water, its great eyes fixed on him, he feels a strange sensation of respect, as though he were in the presence of a very wise and very old animal, whose tranquillity it would be best not to disturb.” One of Cousteau’s assistants adds: “I have often had the impression that they are ‘reflecting.’” Other divers and lab researchers make the same sort of comment, describing the same eerie sense of encounter, recognition, even mutuality. Lately I’ve had occasion to experience it myself, during three evenings of octopus-watching in a small university room filled with quietly gurgling tanks: the potent, expressive gaze of the octopus. These animals don’t just gape at you glassily, like a walleye. They make eye contact, as though they are someone you should know.

  One reason for the potency of that stare is simply a matter of proportion. Relative to the body size of a given octopus, the eyes are, like the brain, unusually large. (The ultimate record in this regard belongs to that octopus cousin the giant squid, with an eyeball up to fifteen inches across, the largest on Earth and twice the size of the eye of a blue whale.) Octopus eyes are also protrusive and mobile, bulging up periscopically when the creature’s attention is caught, swiveling far enough fore and aft to cover all 360 degrees of horizon. But the real magic behind the octopod gaze is that those eyes bear a startling structural similarity to our own.

  It’s an exemplary instance of the phenomenon called convergent evolution. Two separate evolutionary paths are followed for millions of years by two disparate groups of creatures, arriving eventually at two separate but (coincidentally) very similar solutions to a common problem. In this case, the problem of translating incident light rays into coherent images conveyable to the brain. The vertebrate eye—the model we humans share with cougars and eagles and rattlesnakes, all having inherited the pattern commonly—is an ingenious contrivance combining a cornea, a crystalline lens, an adjustable iris, and a retina. That such an organ evolved even once, within the vertebrate line, represents a remarkable triumph of time and trial-and-error over improbability. The still more improbable happenstance is that two very similar versions of this piece of biological engineering have appeared independently. The other belongs exclusively to the octopods and their close kin. Each of those squid and octopus eyes consists of a cornea, a crystalline lens, an adjustable iris, and a retina, functioning together in much the same way as ours.

  And the octopuses are also endowed with an eyelid, so that they can wink at us fraternally.

  Among all the sea’s octopod eyeballs, the most imposing belong to Octopus dofleini. This is the giant that has impressed Cousteau and others with its dignified presence, as though it were “a very wise and very old animal.” The wisdom part is quite possible, but the great agedness is an illusion.

  Octopuses grow quickly to adulthood and die at an early age, in most cases right after their first breeding experience. Two or three years is a full life span, even for the larger Mediterranean octopuses, which might grow in that brief time from the size of a flea to the size of an ottoman. An octopus can achieve such speedy growth—almost doubling its weight each month throughout most of its life—because of its exceptional metabolic efficiency in converting food protein to octopus protein. And at this process O. dofleini is probably unsurpassed. Surviving longer than other species, to the grand age of five or maybe a little beyond, some giant Pacific octopuses attain awesome sizes.

  They live mainly in sea-bottom caves along the coast of the northern Pacific, from California up through British Columbia and Alaska and across to Japan. The caves give them security from predation and, at mating time, a good place to brood eggs. They seem to prefer the range of moderate depths from
the intertidal zone down to a hundred fathoms, and by most accounts they are exceedingly shy. Until three or four decades ago, O. dofleini were known almost solely from commercial fishermen, who occasionally, inadvertently and probably to their own vast alarm, brought one up in a trawl net. After World War II, improved diving equipment (especially scuba) opened a new degree of human access to those deeper caves. Reports of larger and larger dofleini began to appear. Cousteau mentions one specimen, spotted off Seattle, with an arm span of 30 feet and a weight around 200 pounds. Another diver has told William High, of the National Marine Fisheries Service, about bringing up several 400-pound dofleini during his commercial octopus-fishing days, as well as a single huge individual that went 600 pounds.

  Then the inevitable happened. Someone had a clever idea, and in 1956 hundreds of divers converged on Puget Sound to compete in an event billed as the World Octopus-Wrestling Championship. It became an annual tradition.

  The biggest specimens of dofleini were smoked out of their caves with solutions of noxious chemicals and wrestled up onto land by divers working in teams, there to be weighed and measured and admired. Dealing underwater with an octopus that large requires—from a human in scuba gear—equal measures of skill, coolheadedness, and lunatic daring. Dofleini are naturally timid but also quite strong, and they do have four times as many arms. Panic-stricken dofleini have been known to pin a man’s arms to his sides, pull off his face mask, yank out his mouthpiece. There have even been several instances when a big octopus pounced on the back of an unsuspecting diver from a rock ledge overhead. If one diver becomes trapped, in a situation like that, the usual procedure seems to be for his buddy to commence slicing away octopod arms with a knife or go for the eye with a spear.

  After those “wrestling” championships each year, the healthy octopuses were carefully released back into the sea. No harm done. No permanent toll on the giant octopus population. Right? At least, that was the assumption. But one woman diver who took part in the roundups has told Cousteau: “It is hard to keep in mind that octopuses of the size and weight of these are really very fragile animals, highly developed and with a very sensitive nervous system. They seem to succumb easily to nervous disorders. If a diver is too rough with an octopus, even without actually hurting it physically, it happens that the animal goes into a state of emotional shock and sometimes dies.”

  Let me recapitulate. It seems that 1) octopuses in the 200-pound range, or larger, cowering in sea caves off the coast near Seattle, and 2) known for their high-strung susceptibility to nervous disorders, have been 3) kidnapped and terrorized intermittently by strange visitors in black neoprene, these latter often armed with knives and spears. Consequently it can be assumed that 4) eyeballs humanlike but the size of grapefruit now gaze out from those caves, furtively, trepidatiously, some of them no doubt looking just a bit addled—looking, that is, as though they might belong to animals that, like Pynchon’s beast, are in not quite the best mental health.

  My own view is this: Any giant octopus that grabs hold of a passing human probably has some pretty good reason. If not an unanswerable grievance, then at least a plausible insanity defense.

  Or maybe the grabby creature is just desperate to communicate. Snatching that startled human by the neoprene lapels; exigent as the Ancient Mariner; transfixing the man or woman with a big glittering eye. As though to say: Listen. We know who you are. And we’ve seen what you do. But unfortunately the octopuses, for all their intelligence, for all their sensitivity, for all their evolutionary sophistication, are born mute.

  Avatars of the Soul in Malaya

  CONSIDER NOW THE LEPIDOPTERA, in all their vacant splendor.

  They are the bimbos of the natural world: more beautiful and less interesting, arguably, than any other order of animals. An evolutionary experiment in sheer decorative excess, with a high ratio of surface to innards. They move through the air like pulses of idle thought. They have a weakness for flowers. They are prodigiously diverse without being adventurous: roughly 150,000 known species, all of which behave pretty much alike; 150,000 distinct patterns, but in each case a six-legged worm strung between kites. They are silent. Detached and diaphanous. Generally they possess neither teeth nor jaws. They feed pacifically on plant liquids or (some species) just go hungry through their entire adulthood. Fly on wings that are fleshless and papery, flashing bright iridescent colors produced by the devious exploitation of tiny prisms and mirrors. Certainly these are real physical creatures, yes; then again, they just don’t seem to be quite all there. Aristotle was onto something, I think, when in the fourth century B.C. he used the Greek word psyche to mean both “soul” and “butterfly.”

  They might be insects. Or they might be platonic ideas.

  In classical Greece and then later in Rome, this link with the spiritual realm was applied to both major subgroups of Lepidoptera, the moths as well as the butterflies. Both moths and butterflies were delicate enough to suggest a pure being, freed of its carnal envelope. Both were known to perform a magical metamorphosis—from fat, ugly caterpillar to gorgeous, airborne adult, with a dormant pupal stage in between—that put humans in mind of resurrection from the grave. Moths may have been even more suited than butterflies to bearing this burden of symbolism, in that moths, like ghosts, fly at night. Tomb-sculpture designs from imperial Rome have survived (thanks to later Italian scholars, who copied them before the original stones were lost) on which appear butterflies and moths carved to represent the departing souls of the dead. And the motif has endured. One marker from a nineteenth-century grave in Massachusetts shows a common monarch, Danaus plexippus, freshly emerged from its chrysalis and winging away—the soul as butterfly.

  Clearly mankind has taken some small comfort over the past couple millennia from gazing upon Lepidoptera and positing this odd connection between their substance and our essence. Why the Lepidoptera? Maybe it’s because they are detached and diaphanous, because their beauty is of an otherworldly sort. No sting, no bite, no bothersome buzz. Strict vegetarians. They represent an ideal of sweetness and gentle grace that seems almost innocent of the whole merciless evolutionary free-for-all. No wonder they are, zoologically, so godawful boring to contemplate.

  But wait. That’s only the traditional, happy-time view of the Lepidoptera. It applies to no more than about 149,999 species. And it takes no account whatever of a small Malayan jungle moth called Calpe eustrigata.

  Here finally is a moth with character, a moth with edge, a moth unafraid to besmirch itself in the Darwinian struggle. A moth unique, among all known moths, for its dietary behavior. Calpe eustrigata sucks blood from humans.

  There is no common name for Calpe eustrigata, but it belongs to a large family of drab little moths called the noctuids, notable in this country mainly for the damage that larvae of some species do to vegetables and grain. These are your basic cutworms and ear-worms and celery-loopers. Such dreary noctuids can be plentiful, species by species, but C. eustrigata is quite rare. It was discovered some decades ago by an admirable fanatic named Hans Bänziger, a Swiss entomologist who was spending two years in the jungles of Thailand for research on a different group of noctuids.

  In Thailand the work progressed satisfactorily; the moths behaved more or less as expected, and there was no sign of any such creature as C. eustrigata. Toward the end of two years, Bänziger got down into Malaya (as peninsular Malaysia was then called), where he wanted to investigate several species that were opportunistic blood-drinkers of a purely nonaggressive sort. These Malayan moths were known to lick at the open wounds of large mammals and to follow after mosquitoes (which are greedy and slovenly as they extract blood), lapping up what was spilled. Again the moths behaved as expected. At least they did until, late one night, Bänziger captured a particular specimen. He found it alighted on a water buffalo.

  Bänziger’s own account, from a back issue of the journal Fauna, sets the scene: “I had become suspicious of this insect species because of a photograph taken a few days befo
re while it was feeding on a Malay tapir. The photograph showed something very strange about the moth’s proboscis. Now with a live specimen I intended to study its feeding behavior on myself. That night was to become especially exciting! Having incised my finger with a scalpel to draw fresh blood, I offered my finger to the caged moth. The moth climbed onto my finger and did in fact plunge its proboscis into the blood, but it appeared to imbibe none. Instead it stuck its straight, lancelike proboscis into the wound and, without any regard for the donor, penetrated the flesh. The pain I felt caused me to utter a cry of—joy!” Lucky the man who so loves his work. “I had discovered a moth which pierces to obtain blood.” If you were a lepidopterist, you’d see that it was a pretty big moment in history.

  During a month in Malaya, Bänziger found only twenty-four more specimens of C. eustrigata, but he kept them busy poking and sucking at his hand. As an experimentalist, he lacked nothing by way of commitment. “Blood-sucking occupied from 10 to 60 minutes and blood continued to flow out of the wound for a few minutes after cessation. Hours and sometimes even days later, the wound was still itching.” The remarkable aspects of all this involved not just the matter of behavior (including Bänziger’s behavior) but the matter of anatomy. Lepidopteran mouth structures are totally different from those of, say, a mosquito. The standard equipment for butterflies and moths is a long flexible tube that remains coiled up under the head until, when needed, it can be sprung out straight by hydraulic pressure, like one of those paper noisemakers in the mouth of a drunk on New Year’s Eve. In extended position it allows the insect to suck nectar from the reservoir of a deep flower. But this thing is a drinking straw, not a drill. Until Bänziger, no lepidopterist had ever seen a moth whose proboscis could be stabbed through human flesh.