Inner Visions

Something about dolphins—or, actually, about us—impels us to believe that they are better than we are. Perhaps our discomfiture over our own human shortcomings makes us yearn to believe that there is something, someone, more perfected than us, either in the sky or in the sea. We needn’t worry. Lots of things qualify, in their qualified ways, as better than we. Including certain people. And, as my dogs are constantly explaining, many of the most important things are said without words. And maybe dolphins are better at certain things—but not at talking.

From everything we understand at present, it appears that dolphins’ whistles convey information that is simple and repetitive, not complex, not specific, not highly patterned; not a word-based, large-vocabulary, syntax-equipped language. Yet few who love dolphins—myself included—really want to accept that. The calls just sound too complicated and varied. And so, waiting, we listen, hoping someday to hear more.

 

 

It must say something about humans or whales—or both—that some people have put a lot of time into listening to whales. In the 1970s, scientists realized that humpback whales sing structured songs. Strangely, even if they’re coming from thousands of miles apart, males converging on mating grounds all sing the same song. Humpback song is composed of about ten different consecutive themes, each made of repeated phrases of about ten different notes requiring about fifteen seconds to sing. The song lasts about ten minutes. Then the whale repeats it. For hours in the ocean, in their season of courtship, the whales sing. Each ocean’s song is different, and over months and years it changes in the same way for the thousands of whales in each ocean, the song somehow a continual work in progress, fully shared.

Sometimes the change is sudden and radical. In the year 2000, researchers announced that humpbacks’ song off Australia’s east coast was “replaced rapidly and completely” by the song Indian Ocean humpbacks off Australia’s west coast had been singing. It seems that a few “foreigners” made the trek west to east, and their song became such an instant hit with the easterners that everybody had to sing it. The researchers wrote, “Such a revolutionary change is unprecedented in animal cultural vocal traditions.” And once a phrase in the song disappears, it has never again been heard, despite over twenty years of eavesdropping. What do the songs mean? Researcher Peter Tyack says, “We may have to thank the evolving aesthetic sensibilities of generations of female humpbacks for the musical features of the males’ songs.” Songs of humpback whales, by the way, have sold millions of recordings. We share that aesthetic. That might be both the biggest mystery and the best evidence of like-mindedness.

 

 

Killer whales in a group can be spread out over 150 square miles—and all be in vocal contact. Through the hydrophones I’ve been hearing their chirps, whistles, honks, whoops, and whatever you’d call what sounds like wet hands on a latex balloon. Most of the calls have sudden shifts or sweeps in pitch, making them recognizable through background noise. What song are the whales singing? What epic poetry of their origin are they reciting? If there’s a code, no one’s cracked it. Unless Ken sort of has. “Since the first recording in 1956,” he says, “they’ve been saying the same things over and over and over. I’ve thought, ‘Don’t they have anything new to say?’ They don’t seem to be saying stuff to each other like ‘Big fish here,’ or whatever. They don’t seem to have one call for ‘prey’ and another for ‘hello.’” Each of their calls may be heard whenever the whales are vocalizing; it doesn’t matter what they’re doing. Ken feel certain, however, that “they know—from just a peep—who that was and what it’s about. I’m sure that to them, their voices are as different and recognizable as our voices are to us. I’m pretty sure they have names for each other like other dolphins do, and that right now some of what we’re hearing repeated are those signature calls.”

There may be more communicated in the emotion that comes across. “A call might sound like Ee-rah’i, ee-rah’i,” says Ken. “Does that mean something specific? Or does its intensity carry meaning? When the pods congregate, you sense intensity, excitement; it sounds like a party. When they’re excited, the calls get higher and shorter—in other words, shrill.” The calls might not have syntax, but what comes across among the whales is who, where, mood, and, perhaps, food. Pituuu is a call that predominates when whales are synchronized in their actions (“We’re doing this now; let’s keep doing this together”); Wee-oo-uuo is a call of tranquillity and relaxed contact (‘How we doing—good? Good”). It’s enough to maintain coordination, cohesion, group identity, and group integrity—for decades.

 

 

So is this calling we’re hearing also the sonar they use to find fish?

“No. Sonar sounds like—” Ken rapidly clicks his tongue. “Sometimes they come on the speakers with those clicks; that’s them ‘looking’ for fish.”

Clicks return an echo that the brain can use to extract information. Dolphins using sonar can detect a ping-pong ball one hundred yards away, a distance at which many humans would fail to see it. They can track rapidly swimming fish well enough to capture them, meanwhile avoiding obstacles while traveling at high speeds. They click fast: each click lasts just ten millionths of a second, and they make up to four hundred clicks per second.

Resident killer whales produce a series lasting about seven to ten seconds, called a click train. Residents produce click trains twenty-seven times more often and lasting twice as long as transients’. Transients are cryptic clickers. Transients sometimes produce just one single, softer click. Seals and porpoises have a hard time hearing one click acoustically camouflaged amid the ocean’s constant aural static of little pops and the crackling of calling shrimp and other creatures, which can sometimes sound like something’s frying in the ocean. Jacques Cousteau famously called the ocean “the silent world,” but sound travels much better in water than in air, and many sea creatures use the ocean’s sonic superhighway to great advantage. Or are betrayed by it.

Killer whales don’t just make clicks; they’re also always listening for a splash or a puff of breath. Consequently, there’s an acoustic arms race among the high-acumen killers and their astute dolphin prey. Mammal-hunting killer whales sometimes hunt Dall’s porpoises. The porpoises also use sonar, which you’d think would be like ringing a dinner bell on themselves. But their clicks are above the hearing range of killer whales. Such a separation could evolve and be maintained pretty simply: a porpoise whose click voice is low enough for killer whales to hear gets eaten. Higher-pitched callers literally survive at higher frequencies.

 

 

Only rather recently have people known about sonar in animals. Researchers didn’t grasp dolphins’ sonar until 1960. In 1773, the Italian Lazzaro Spallanzani observed that in a totally dark room, owls were helpless but bats flew freely. He was later astonished to find that blinded bats could avoid obstacles just as effectively as bats who could see. But how? In 1798, a Swiss experimenter named Charles Jurine plugged bats’ ears; they crashed into things. He was baffled because the bats seemed silent. And when he announced that bats’ hearing had something to do with their ability to navigate, his findings were first ridiculed and then, for a century, forgotten. (The history of rejection of new ideas that turn out to be true—including, famously, the idea that microscopic “germs” can cause disease and that physicians and surgeons should wash their hands—should caution us against too quickly dismissing the seemingly absurd. Whales, as you will read in the next few chapters, do some seemingly absurd things, still beyond human understanding.) In 1912, the engineer Sir Hiram Maxim thought bats produced sounds humans couldn’t hear; but he suspected that the sound came from their wings.

In 1938, the “Spallanzani bat problem” was solved at Harvard by G. W. Pierce and Donald Griffin, who used a special microphone and receiver and tape-recorded bats emitting sounds above the range of human hearing. When they proved that bats’ could hear sounds in those ranges, our own bat-sonar blindfold came off. In World War II, humans devised analogous echo-based sonar and radar systems for military purposes. About a decade after Pierce and Griffin, Arthur McBride of Marine Studios (later Marineland), in Florida, noticed that during capture on very dark nights, bottlenose dolphins could avoid fine mesh nets and detect openings. In 1952, two researchers first publicly hypothesized that “the porpoise, like the bat, may orient itself with respect to objects in its environment by echolocation.” Then experimenters proved that dolphins can hear sounds too high for humans. And Marineland’s curator Forrest Wood suggested that captive dolphins seemed to be “echo-investigating” objects in their tank.

Not until 1956 did researchers report that captive dolphins emitted sound pulses as they approached dead fish, that dolphins could avoid clear glass panels that were moved around their tank, and that they could in darkness avoid suspended obstacles and identify a kind of fish they liked when it was presented alongside a fish they didn’t like. (Much more impressively, many free-living dolphins hunt in the dark of night, chasing—and catching—small, agile fish.) When, in 1960, Kenneth Norris placed rubber suction cups over dolphins’ eyes, they swam just fine, emitted sound pulses, avoided suspended objects, and navigated mazes. From the 1960s to the 1990s, other experimenters showed that similarly blindfolded dolphins, belugas, porpoises, and certain whales retrieved tossed fish and toys, swam obstacle courses, and basically had no trouble being sightless. Now we know that sperm whales, killer whales, other dolphins, and bats really do navigate by sound. In all the generations before, humans had been blind to the world of living sonar.

 

 

So much of a dolphin’s head hardware and brain wiring is devoted to production and analysis of underwater sound, it’s as if each individual functions as a sophisticated undersea spying station. But we humans, too, in our way, come well equipped for analyzing sound. We listen to recordings of orchestras or rock bands and, from the mere vibration of the speakers, effortlessly reassemble a coherent soundscape of violins, horns, keyboards, and drum fills, instantly identifying our guitar heroes and singing sensations. Whales likely hear their friends and families’ social voices quite similarly to the way we hear ours. After all, it’s easy for researchers to listen to their calls and know which pod is talking.

But because we’re such visually navigating animals, sonar navigation is for us almost impossible to imagine. Our analogy is sight. When light bounces off everything, some goes into our eyes, and our brain makes for us an extraordinarily detailed vision of the world around us. We see, in other words, echoes of light.

Imagine being in a dark place with a flashlight, the beam originating from you, bouncing around so you can scan and see what’s there. Now imagine that instead of a light beam, your body is producing a beam of sound, and that your brain can still make a detailed assessment of what the beam is bouncing off. Not an image—not visual, perhaps—but enough to tell you with great precision what’s there.

Turns out, when sonar signals are slowed so that humans can hear them, even humans can tell by the sound of the echoes whether the test targets are made of steel, bronze, aluminum, or glass—with 95 to 98 percent accuracy. Turns out, human hearing is very good at making distinctions. Think of how easily we recognize voices on the telephone or follow one conversation in a noisy restaurant.

We can’t imagine how animals experience sonar without reference to sight. It’s assumed that they hear the echoes and make a kind of auditory sound map so fine that they can use hearing alone to find and catch agile fish. We imagine that whales use sonar to make a sound “picture,” as sharply focused as the light picture we assemble into vision. But I wonder: Might they actually see their sonar?

Consider: eyes don’t see; brains see. Consider, too: there is nothing inherently “visual” about “light.”

What we call “visible light” is a narrow range of wavelengths that is a very small part of the electromagnetic spectrum. Above and below the wavelengths that humans can see are others, just as real, called gamma waves, X-rays, infrared radiation, ultraviolet light, radio waves, and others. We don’t see those because human eyes do not produce and send impulses about them along our optic nerves to our brain. Some other species, though, do see ultraviolet and infrared. Various insects, fishes, amphibians, reptiles, and birds—and mammals including at least some rodents, marsupials, moles, bats, cats, and dogs—see into the ultraviolet. Some snakes use pit organs—not their eyes—like pinhole cameras to visualize infrared energy emitted by warm bodies.

Perception of light and experience of vision happen inside the human brain. With our eyes closed, we can still see our desires and dreads in the “mind’s eye,” and in dreams. You can rummage around in a bin with your hand while visualizing something familiar you’re “looking” for. With our eyelids open, our eyes create impulses based on the pattern of electromagnetic wavelengths striking our retinas, then send the impulses along optic nerves into vision centers in the brain that decode the impulses; the brain creates a picture, then presents the picture to our conscious minds for our viewing pleasure. So our eyes don’t really “see the object”; the brain creates images from reflected energy. And there is nothing “red” about the wavelengths we see as red; color perception is just how our brain color-codes incoming impulses of certain wavelengths. A video camera sends impulses through wires to a monitor that turns the impulses into pictures. When you look at the monitor, your eye, nerves, and brain instantly do the same thing.

Like light, sound comes in waves. Like vision, hearing is created in and by the brain. Electromagnetic wavelengths we happen to be able to “see,” we call “light,” and vibrational wavelengths we happen to hear, we call “sound.” Above and below what we can hear and see are other wavelengths that fill the world but lie outside of our senses.

Is it possible that whales’ and bats’ brains, using sonar-reflection input, create actual vision? I can’t see why not. Might a whale’s brain take nerve impulses from its sonar echoes, just as it takes nerve impulses from light, and turn them into an image that the whale—or a bat—might literally see? Sound and sight aren’t as separate as they seem. When some people hear specific musical notes, they actually see certain colors. It’s called synesthesia. On my boat I have a sonar machine that makes pulses of sound and then collects reflected echoes and turns them into electrical impulses that run through a wire to the machine for processing. The sound collector, wire, and processor act like an ear, a nerve, and a brain. The processed echoes get converted to visual images that appear on a screen. With the help of the machine, I’m using sonar to literally see the bottom contour, boulders, and slopes where fish live, and the position of fish in the water.

Perhaps the most amazing practitioner of echolocation among humans is Daniel Kish, blind since he was one year old, who early in life discovered that making clicking noises helped him get around. Much of his brain must be reassigned to sound, because he uses his own clicks to navigate. He can ride a bicycle in traffic (hard to imagine), and he has founded World Access for the Blind to teach other blind people to use their own sonar—to summon, as it were, their inner dolphin. Sounds from his tongue clicks, he explains, “bounce off surfaces all around and return to my ears as faint echoes. My brain processes the echoes into dynamic images.… I construct a three-dimensional image of my surroundings for hundreds of feet in every direction. Up close, I can detect a pole an inch thick. At 15 feet, I recognize cars and bushes. Houses come into focus at 150 feet.” This is all so hard to imagine, people have wondered if he is telling the truth. But he’s not alone, and his claims appear to check out. He says, “Many students are surprised how quickly results come. I believe echolocation capacity is latent within us.… The neural hardware seems to be there; I’ve developed ways to activate it. Vision isn’t in the eyes; it’s in the mind.”

So, is it possible that a dolphin such as a killer whale might actually see the echoes?

It’s possible; no one knows. The least we can say about our shared, compared sense of the world is that while we are mostly visual and can also hear well, they are mostly acoustical, though they can also see. Same senses, different emphases.

 

 

If you imagine the very slow changes over millions of years that turned some mammals into apes and others into whales, we seem to have grown very distant indeed, almost estranged. But is that really a long time, or a big difference? Take the skin off, and the muscles are much the same, the skeletal construction nearly identical. The brain cells, under a microscope, are impossible to distinguish. If you imagine the process very much sped up, you see something real: dolphins and humans, both already having shared a long history as animals, vertebrates, and mammals—same bones and organs doing the same jobs, same placenta and that same warm milk—are basically the same, in merely shape-shifted proportions. It’s a little like one person outfitted for hiking and another for scuba diving.

Whales are nearly identical to us in every way except their outer contours. Even their hand bones are identical to ours, just shaped a little differently and hidden in mittens. And dolphins still use those hidden hands for handlike gestures of touch and calming reassurance. (In any group of spinner dolphins, at any given time one-third are usually caressing with flippers or making bodily contact, a bit like primates grooming.) From primates to ponies to penguins to peepers to pupfish, the circulatory, nervous, and endocrine systems work in similar ways. And inside the cells? Pretty much the same structures with the same functions, down to amoebas, sequoias, and portobello mushrooms.

Living diversity is astonishing, but as you peel layers of difference, you encounter similarities more stunning. The extreme shrinkage of hind limbs that granted whales their swimming bodies was largely accomplished by the loss of one gene. (Geneticists call the gene “sonic hedgehog.”) In your body, this same gene gave you “normal” limbs. Normal for a human, that is. If you look at side-by-side drawings of human, elephant, and dolphin brains, the similarities overwhelm the differences. We are essentially the same, merely molded by long experience into different outer shapes for coping with different outer surroundings, and wired inside for special talents and abilities. But beneath the skin, kin. There is no other animal like us. But don’t forget: there are no other animals like each of them, either.