When I walk along the floe edge I think of that story. I have no ear educated as was his companion’s to anticipate the arrival of the walrus. A native ear. Experience. I walk here susceptible as any traveler to the unknown.

  I stood still occasionally to listen. I heard only the claver of birds. Then there was something else. I had never heard the sound before, but when it came, plosive and gurgling, I knew instinctively what it was, even as everyone in camp jumped. I strained to see them, to spot the vapor of their breath, a warm mist against the soft horizon, or the white tip of a tusk breaking the surface of the water, a dark pattern that retained its shape against the dark, shifting patterns of the water. Somewhere out there in the ice fragments. Gone. Gone now. Others had heard the breathing. Human figures in a camp off to the west, dark lines on the blinding white ice, gesture toward us with upraised arms.

  The first narwhals I ever saw lived far from here, in Bering Strait. The day I saw them I knew that no element of the earth’s natural history had ever before brought me so far, so suddenly. It was as though something from a bestiary had taken shape, a creature strange as a giraffe. It was as if the testimony of someone I had no reason to doubt, yet could not quite believe, a story too farfetched, had been verified at a glance.

  I was with a bowhead whale biologist named Don Ljungblad, flying search transects over Bering Sea. It was May, and the first bowheads of spring were slowly working their way north through Bering Strait toward their summer feeding grounds in the Chukchi and Beaufort seas. Each day as we flew these transects we would pass over belukha whale and walrus, ringed, spotted, and ribbon seals, bearded seals, and flocks of birds migrating to Siberia. I know of no other region in North America where animals can be met with in such numbers. Bering Sea itself is probably the richest of all the northern seas, as rich as Chesapeake Bay or the Grand Banks at the time of their discovery. Its bounty of crabs, pollock, cod, sole, herring, clams, and salmon is set down in wild numbers, the rambling digits of guesswork. The numbers of birds and marine mammals feeding here, to a person familiar with anything but the Serengeti or life at the Antarctic convergence, are magical. At the height of migration in the spring, the testament of life in Bering Sea is absolutely stilling in its dimensions.

  The two weeks I spent flying with Ljungblad, with so many thousands of creatures moving through the water and the air, were a heady experience. Herds of belukha whale glided in silent shoals beneath transparent sheets of young ice. Squadrons of fast-flying sea ducks flashed beneath us as they banked away. We passed ice floes stained red in a hundred places with the afterbirths of walrus. Staring all day into the bright light reflected from the ice and water, however, and the compression in time of these extraordinary events, left me dazed some evenings.

  Aspects of the arctic landscape that had become salient for me—its real and temporal borders; a rare, rich oasis of life surrounded by vast stretches of deserted land; the upending of conventional kinds of time; biological vulnerability made poignant by the forgiving light of summer—all of this was evoked over Bering Sea.

  The day we saw the narwhals we were flying south, low over Bering Strait. The ice in Chukchi Sea behind us was so close it did not seem possible that bowheads could have penetrated this far; but it is good to check, because they can make headway in ice as heavy as this and they are able to come a long way north undetected in lighter ice on the Russian side. I was daydreaming about two bowheads we had seen that morning. They had been floating side by side in a broad lane of unusually clear water between a shelf of shorefast ice and the pack ice—the flaw lead. As we passed over, they made a single movement together, a slow, rolling turn and graceful glide, like figure skaters pushing off, these 50-ton leviathans. Ljungblad shouted in my earphones: “Waiting.” They were waiting for the ice in the strait to open up. Ljungblad saw nearly 300 bowheads waiting calmly like this one year, some on their backs, some with their chins resting on the ice.

  The narwhals appeared in the middle of this reverie. Two males, with ivory tusks spiraling out of their foreheads, the image of the unicorn with which history has confused them. They were close to the same size and light-colored, and were lying parallel and motionless in a long, straight lead in the ice. My eye was drawn to them before my conscious mind, let alone my voice, could catch up. I stared dumbfounded while someone else shouted. Not just to see the narwhals, but here, a few miles northwest of King Island in Bering Sea. In all the years scientists have kept records for these waters, no one had ever seen a narwhal alive in Bering Sea. Judging from the heaviness of the ice around them, they must have spent the winter here.2 They were either residents, a wondrous thought, or they had come from the nearest population centers the previous fall, from waters north of Siberia or from northeastern Canada.

  The appearance of these animals was highly provocative. We made circle after circle above them, until they swam away under the ice and were gone. Then we looked at each other. Who could say what this was, really?

  Because you have seen something doesn’t mean you can explain it. Differing interpretations will always abound, even when good minds come to bear. The kernel of indisputable information is a dot in space; interpretations grow out of the desire to make this point a line, to give it a direction. The directions in which it can be sent, the uses to which it can be put by a culturally, professionally, and geographically diverse society, are almost without limit. The possibilities make good scientists chary. In a region like the Arctic, tense with a hunger for wealth, with fears of plunder, interpretation can quickly get beyond a scientist’s control. When asked to assess the meaning of a biological event—What were those animals doing out there? Where do they belong?—they hedge. They are sometimes reluctant to elaborate on what they saw, because they cannot say what it means, and they are suspicious of those who say they know. Some even distrust the motives behind the questions.

  I think along these lines in this instance because of the animal. No large mammal in the Northern Hemisphere comes as close as the narwhal to having its very existence doubted. For some, the possibility that this creature might actually live in the threatened waters of Bering Sea is portentous, a significant apparition on the eve of an era of disruptive oil exploration there. For others, those with the leases to search for oil and gas in Navarin and Norton basins, the possibility that narwhals may live there is a complicating environmental nuisance. Hardly anyone marvels solely at the fact that on the afternoon of April 16, 1982, five people saw two narwhals in a place so unexpected that they were flabbergasted. They remained speechless, circling over the animals in a state of wonder. In those moments the animals did not have to mean anything at all.

  We know more about the rings of Saturn than we know about the narwhal. Where do they go and what do they eat in the winter, when it is too dark and cold for us to find them? The Chilean poet and essayist Pablo Neruda wonders in his memoirs how an animal this large can have remained so obscure and uncelebrated. Its name, he thought, was “the most beautiful of undersea names, the name of a sea chalice that sings, the name of a crystal spur.” Why, he wondered, had no one taken Narwhal for a last name, or built “a beautiful Narwhal Building?”

  Part of the answer lies with a regrettable connotation of death in the animal’s name. The pallid color of the narwhal’s skin has been likened to that of a drowned human corpse, and it is widely thought that its name came from the Old Norse for “corpse” and “whale,” nár + hvalr. A medieval belief that the narwhal’s flesh was poisonous has been offered in support of this interpretation, as well as the belief that its “horn” was proof at that time against being poisoned. The eighteenth-century naturalist Buffon characterized the animal for all the generations that would read him as one that “revels in carnage, attacks without provocation, and kills without need.” Among its associations with human enterprise in the inhospitable north is the following grim incident. In 1126, Arnhald, first bishop of Iceland, was shipwrecked off the Icelandic coast. Drowned men and part of the contents of the ship’s hold washed up in a marsh, a place afterward called the Pool of Corpses. Conspicuous among the items of salvage were a number of narwhal tusks, “with runic letters upon them in an indelible red gum so that each sailor might know his own at the end of the voyage.”

  W.P. Lehmann, a professor of Germanic languages, believes the association with death is a linguistic accident. The Old Norse nárhvalr (whence the English narwhal, the French narval, the German Narwal, etc.), he says, was a vernacular play on the word nahvalr—the way high-bred corn is used in place of hybrid corn, or sparrowgrass is used for asparagus. According to Lehmann, nahvalr is an earlier, West Norse term meaning a “whale distinguished by a long, narrow projection” (the tusk).

  Some, nevertheless, still call the narwhal “the corpse whale,” and the unfounded belief that it is a cause of human death, or an omen or symbol to be associated with human death, remains intact to this day in some quarters. Animals are often fixed like this in history, bearing an unwarranted association derived from notions or surmise having no connection at all with their real life. The fuller explanations of modern field biology are an antidote, in part, to this tendency to name an animal carelessly. But it is also, as Neruda suggests, a task of literature to take animals regularly from the shelves where we have stored them, like charms or the most intricate of watches, and to bring them to life.

  The obscurity of narwhals is not easily breeched by science. To begin with, they live underwater. And they live year-round in the polar ice, where the logistics and expense involved in approaching them are formidable barriers to field research, even in summer. Scientists have largely been limited to watching what takes place at the surface of the water in the open sea adjacent to observation points high on coastal bluffs. And to putting hydrophones in the water with them, and to making comparisons with the belukha whale, a close and better-known relative. About the regular periodic events of their lives, such as migration, breeding, and calving, in relation to climatic changes and fluctuations in the size of the population, we know next to nothing.3

  Scientists can speak with precision only about the physical animal, not the ecology or behavior of this social and gregarious small whale. (It is the latter, not the former, unfortunately, that is most crucial to an understanding of how industrial development might affect narwhals.) Adult males, 16 feet long and weighing upwards of 3300 pounds, are about a quarter again as large as adult females. Males are also distinguished by an ivory tusk that pierces the upper lip on the left side and extends forward as much as 10 feet. Rarely, a female is found with a tusk, and, more rarely still, males and females with tusks on both sides of the upper jaw.

  From the side, compared with the rest of its body, the narwhal’s head seems small and blunt. It is dominated by a high, rounded forehead filled with bioacoustical lipids—special fats that allow the narwhal to use sound waves to communicate with other whales and to locate itself and other objects in its three-dimensional world. Its short front flippers function as little more than diving planes. The cone-shaped body tapers from just behind these flippers—where its girth is greatest, as much as eight feet—to a vertical ellipse at the tail. In place of a dorsal fin, a low dorsal ridge about five feet long extends in an irregular crenulation down the back. The tail flukes are unique. Seen from above, they appear heart-shaped, like a ginkgo leaf, with a deep-notched center and trailing edges that curve far forward.

  Viewed from the front, the head seems somewhat squarish and asymmetrical, and oddly small against the deep chest. The mouth, too, seems small for such a large animal, with the upper lip just covering the edge of a short, wedge-shaped jaw. The eyes are located just above and behind the upturned corners of the mouth, which give the animal a bemused expression. (The evolutionary loss of facial muscles, naturalist Peter Warshall has noted, means no quizzical wrinkling of the forehead, no raised eyebrow of disbelief, no pursed lip of determination.) A single, crescent-shaped blowhole on top of the head is in a transverse line with the eyes.

  Narwhal calves are almost uniformly gray. Young adults show spreading patches and streaks of white on the belly and marbling on the flanks. Adults are dark gray across the top of the head and down the back. Lighter grays predominate on top of the flippers and flukes, whites and light yellow-whites underneath. The back and flanks are marbled with blackish grays. Older animals, especially males, may be almost entirely white. Females, say some, are always lighter-colored on their flanks.

  The marbled quality of the skin, which feels like smooth, oiled stone, is mesmerizing. On the flukes especially, where curvilinear streaks of dark gray overlap whitish-gray tones, the effect could not be more painterly. Elsewhere on the body, spots dominate. “These spots,” writes William Scoresby, “are of a roundish or oblong form: on the back, where they seldom exceed two inches in diameter, they are the darkest and most crowded together, yet with intervals of pure white among them. On the side the spots are fainter, smaller, and more open. On the belly, they become extremely faint and few, and in considerable surfaces are not to be seen.” These patterns completely penetrate the skin, which is a half-inch thick.

  In the water, depending on sunlight and the color of the water itself, narwhals, according to British whaling historian Basil Lubbock, take on “many hues, from deep sea green to even an intense lake [blue] colour.”

  Narwhals are strong swimmers, with the ability to alter the contours of their body very slightly to reduce turbulence. Their speed and maneuverability are sufficient to hunt down swift prey—arctic cod, Greenland halibut, redfish—and to avoid their enemies, the orca and the Greenland shark.

  Narwhals live in close association with ice margins and are sometimes found far inside heavy pack ice, miles from open water. (How they determine whether the lead systems they follow into the ice will stay open behind them, ensuring their safe return, is not known.) They manage to survive in areas of strong currents and wind where the movement of ice on the surface is violent and where leads open and close, or freeze over, very quickly. (Like seabirds, they seem to have an uncanny sense of when a particular lead is going to close in on them, and they leave.) That they are not infallible in anticipating the movement and formation of ice, which seals them off from the open air and oxygen, is attested to by a relatively unusual and often fatal event called a savssat.

  Savssats are most commonly observed on the west coast of Greenland. Late in the fall, while narwhals are still feeding deep in a coastal fiord, a band of ice may form in calm water across the fiord’s mouth. The ice sheet may then expand toward the head of the fiord. At some point the distance from its landward to its seaward edge exceeds the distance a narwhal can travel on a single breath. By this time, too, shorefast ice may have formed at the head of the fiord, and it may grow out to meet the sea ice. The narwhals are thus crowded into a smaller and smaller patch of open water. Their bellowing and gurgling, their bovinelike moans and the plosive screech of their breathing, can sometimes be heard at a great distance.

  The Danish scientist Christian Vibe visited a savssat on March 16, 1943, on the west coast of central Greenland. Hundreds of narwhals and belukhas were trapped in an opening less than 20 feet square. The black surface of the water was utterly “calm and still,” writes Vibe. “Then the smooth surface was suddenly broken by black shadows and white animals which in elegant curves came up and disappeared—narwhals and white whales by the score. Side by side they emerged so close to each other that some of them would be lifted on the backs of the others and turn a somersault with the handsome tail waving in the air. First rows of narwhal, then white whales and then again narwhals—each species separately. It seethed, bobbed, and splashed in the opening. With a hollow, whistling sound they inhaled the air as if sucking it in through long iron tubes. The water was greatly disturbed … and the waves washed far in over the ice.” The splashed water froze to the rim of the breathing hole, as did the moisture from their exhalations, further reducing the size of the savssat. In spite of the frenzy, not a single animal that Vibe saw was wounded by the huge tusks of the narwhal.4

  The narwhal is classed in the suborder Odontoceti, with toothed whales such as the sperm whale, in the superfamily Delphinoidea, along with porpoises and dolphins, and in the family Monodontidae with a single companion, the belukha. In contrast to the apparently coastally-adapted belukha, biologists believe the narwhal is a pelagic or open-ocean species, that it is more ice-adapted, and that it winters farther to the north. Extrapolating on the basis of what is known of the belukha, it is thought that narwhals breed in April and give birth to a single, five-foot, 170-pound calf about fourteen months later, in June or July. Calves carry an inch-thick layer of blubber at birth to protect them against the cold water. They appear to nurse for about two years and may stay with their mothers for three years, or more. Extrapolating once again from the belukha, it is thought that females reach sexual maturity between four and seven years of age, males between eight and nine years.

  Narwhals are usually seen in small groups of two to eight animals, frequently of the same sex and age. In the summer, female groups, which include calves, are sometimes smaller or more loosely knit than male groups. During spring migration, herds may consist of 300 or more animals.

  Narwhals feed largely on arctic and polar cod, Greenland halibut, redfish, sculpins, and other fish, on squid and to some extent on shrimps of several kinds, and on octopus and crustaceans. They have a complex, five-chambered stomach that processes food quickly, leaving undigested the chitinous beaks of squid and octopus, the carapaces of crustaceans, and the ear bones and eye lenses of fish, from which biologists can piece together knowledge of their diets.

  Two types of “whale lice” (actually minute crustaceans) cling to their skin, in the cavity where the tusk passes through the lip, in the tail notch in the flukes, and in wounds (all places where they are least likely to be swept off by the flow of water past the narwhal’s body). The tracks of the sharp, hooked legs of these tiny creatures are sometimes very clear on a narwhal’s skin. Older animals may carry such infestations of these parasites as to cause an observer to wince.