The Strange and Secret Ways That Animals Perceive the World


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One evening almost sixty years ago, a Tufts University researcher named Roger Payne was working in his lab when he heard a radio report about a whale that had washed up on a beach nearby. Although it was a cold, wet March night, he decided to drive to the shore. When he arrived, he discovered that the animal had been mutilated. Two passersby had carved their initials in its flanks. Someone had hacked off its flukes, and another person, or perhaps the same one, had stuck a cigar butt in its blowhole. Payne stood in the rain for a long time, gazing at the corpse. He had been studying moths; now he decided to switch his attention to cetaceans.

Aside from the dead one, Payne had never actually seen a whale, nor did he know where whales could be observed. At the suggestion of an acquaintance, he made his way to Bermuda. There he met an engineer who had worked for the United States Navy, monitoring Soviet submarines via microphones installed off the coast. While listening for enemy subs, the engineer had chanced upon other undersea sounds. He played a tape of some of them to Payne, who later recalled, “What I heard blew my mind.”

Payne took a copy of the tape home with him. The sounds—made, the engineer had determined, by humpback whales—ranged from mournful wails that evoked the call of a shofar to high-pitched cries that resembled the squeals of piglets. Payne found the tape mesmerizing and listened to it hundreds of times. Finally, it dawned on him that what he was listening to had a structure.

With the help of a machine called a sound spectrograph, Payne converted the voices on the tape into a series of squiggle-like notations. The exercise took years, but eventually it confirmed what he had suspected. The humpbacks always made their wails, squeals, and grunts in a particular order—A, B, C, D, E and never A, B, D, C, E, in Payne’s formulation. The paper in which he announced his discovery appeared in Science in the summer of 1971. “Humpback whales (Megaptera novaeangliae) produce a series of beautiful and varied sounds for a period of 7 to 30 minutes and then repeat the same series with considerable precision,” Payne wrote. Each series, he argued, qualified as a “song.”

While the paper was in the works, Payne arranged to have the humpbacks’ songs released as an LP. The album spent several weeks on the Billboard 200 and sold more than a hundred thousand copies. This was a particularly impressive feat, as one commentator noted, for a “work with no musicians, no lyrics, no danceable beats and actually no singers either. (Humpback whales do not possess vocal cords; they make sound by their pushing air out through their nasal cavities.)” The humpbacks inspired many terrestrial performers; Judy Collins incorporated some of their calls into her album “Whales and Nightingales”; Pete Seeger wrote “Song of the World’s Last Whale”; and the New York Philharmonic played “And God Created Great Whales,” a piece composed by Alan Hovhaness.

In 1977, when NASA launched Voyagers 1 and 2, designed to probe the far reaches of the solar system, the songs of the humpbacks went with them. The agency outfitted each craft with a “golden record” that could be played using a stylus (also included) by any alien who happened to intercept it. The recording featured greetings in fifty-five languages—“Hello from the children of planet Earth,” the English speaker said—as well as a sequence from one of Payne’s whales.

At the time the Voyagers set out, no one knew what, if anything, the humpbacks were trying to convey. Today, the probes are more than ten billion miles from Earth, and still no one knows. But people keep hoping.

Imagine the following scene: You are in a room with an owl, a bat, a mouse, a spider, a mosquito, and a rattlesnake. Suddenly, all the lights go off. Instead of pulling out your phone to call an exterminator, you take a moment to ponder the situation. The bat, you realize, is having no trouble navigating, since it relies on echolocation. The owl has such good hearing that it can find the mouse in the dark. So can the rattlesnake, which detects the heat that the rodent is giving off. The spider is similarly unfazed by the blackout, because it senses the world through vibrations. The mosquito follows the carbon dioxide you’re emitting and lands on your shin. You try to swat it away, but because you’re so dependent on vision you miss it and instead end up stepping on the rattler.

Ed Yong, a science writer for The Atlantic, opens his new book, “An Immense World: How Animal Senses Reveal the Hidden Realms Around Us” (Random House), with a version of this thought experiment. (His version also includes a robin, an elephant, and a bumblebee, though not the potentially fatal encounter with the snake.) Yong is interested in what animals might communicate to us if they could, which is to say, what they perceive. Humans, he points out, see the world one way. Other species see it through very different eyes, and many don’t see it at all. Attempting to exchange one world view—or, to use the term Yong favors, Umwelt—for another may be frustrating, but, he argues, that’s what makes the effort worthwhile. It reminds us that, “for all our vaunted intelligence,” our Umwelt is just one among millions.

Consider the scallop. (What’s sold at the supermarket fish counter is just the muscle that scallops use to open and close their shells; the entire animal resembles a fried egg.) Some species of scallop have dozens of eyes; others have hundreds. Inside them are mirrors, composed of tiny crystals, that focus light onto the retina—retinas, really, since each eye has two. A scallop’s eyes are arrayed around the edge of its body, like spikes on a dog collar.

Our brains combine the information gathered by our two eyes into a single image. With dozens (or hundreds) of eyes, scallops face a steeper challenge. But they don’t have much brainpower to devote to the task. (In fact, they don’t have brains.) In an effort to figure out what the scallops were doing with all their eyeballs, Daniel Speiser, a biologist at the University of South Carolina, developed an experiment he called Scallop TV. He strapped the animals onto little pedestals, planted them in front of a computer monitor, and forced them to watch images of drifting particles. Scallops are filter feeders, meaning that they consume plankton they strain out of the water. Speiser found that if the computer-generated particles were big enough and were moving slowly enough the scallops would open their shells. “It’s wild and creepy to see all of them opening and closing at the same time,” he tells Yong. He thinks that their eyes function independently, like motion detectors. When one eye senses something potentially tasty, it sends a signal to investigate. If Speiser is correct, Yong notes, then even though scallops’ eyes are both numerous and complex, the animals don’t possess what we would think of as vision. They see, he writes, “without scenes.”

“An Immense World” is filled with strange creatures like scallops and strange experiments like Scallop TV. Harbor seals have a fringe of vibration-sensitive whiskers jutting from their snouts and eyebrows. To gauge how sensitive the whiskers are, a team of marine biologists at the University of Rostock, in Germany, trained two harbor seals to follow the path of a miniature submarine. Then they blindfolded the animals and plugged their ears. To study how moths elude bats, scientists at Boise State University cut off some moths’ tails and fitted out others with fake wing extensions. To ascertain whether hermit crabs experience pain, a pair of researchers at Queen’s University Belfast prodded them with electric shocks, and to figure out the same thing for squid a biologist at San Francisco State sliced them with scalpels. When I got to the story of Kathy, a bottlenose dolphin who refused to don a sound-blocking mask that researchers wanted her to wear, I silently cheered for her.

The black ghost knifefish is, as its name implies, a nocturnal hunter. By firing a specialized organ in its tail, a knifefish creates an electric field that surrounds it like an aura. Receptors embedded in its skin then enable it to detect anything nearby that conducts electricity, including other organisms. One researcher suggests to Yong that this mode of perception, known as active electrolocation, is analogous to sensing hot and cold. Another posits that it’s like touching something, only without making contact. No one can really say, though, since humans lack both electric organs and electroreceptors. “Who knows what it’s like for the fish?” Malcolm MacIver, a professor of biomedical engineering at Northwestern, asks.

The most famous iteration of this question comes from the essay “What Is It Like to Be a Bat?,” published in 1974 by the philosopher Thomas Nagel. Bats are closely enough related to humans, Nagel noted, that we believe them capable of what we’d call experience. But how can we get inside their furry little heads? The difficulty is not just that they can’t tell us. It’s that their Umwelt is utterly foreign.

One might try to imagine, Nagel wrote, “that one has very poor vision, and perceives the surrounding world by a system of reflected high-frequency sound signals,” or that “one has webbing on one’s arms, which enables one to fly around at dusk and dawn catching insects in one’s mouth.” But that wouldn’t help much.

“I want to know what it is like for a bat to be a bat,” Nagel insisted. “Yet if I try to imagine this, I am restricted to the resources of my own mind, and those resources are inadequate.” The question “What is it like to be a bat?,” he concluded, is one that people will never answer; it lies “beyond our ability to conceive.”

Yong’s response to Nagel, who makes several appearances in his pages, runs along the lines of “Yes, but . . .” Yes, we can never know what it’s like for a bat to be a bat (or for a knifefish to be a knifefish). But we can learn a lot about echolocation and electrolocation and the many other methods that animals use to sense their surroundings. And this experience is, for us, mind-expanding. Yong speaks to Christopher Clark, a Cornell researcher who in the nineteen-seventies worked with Roger Payne, listening for whales. Whale songs lie at the opposite end of the spectrum from bat calls; they are very low frequency and can travel vast distances. If whales are using their songs to communicate with one another, they are doing so not just across space but also across time. A call made by a humpback near Bermuda would take twenty minutes to reach a humpback swimming off the coast of Nova Scotia. If the Canadian whale answered immediately, it would be forty minutes before the Bermuda whale heard back. To imagine what it’s like to be a whale, “you have to stretch your thinking to completely different levels of dimension,” Clark says.

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