The weird and secret ways animals perceive the world


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One evening nearly sixty years ago, a Tufts University researcher named Roger Payne was working in his lab when he heard a radio report of a whale that had washed up on a nearby beach. Although it was a cold and wet March night, he decided to drive to the shore. When he arrives, he discovers that the animal has been mutilated. Two passers-by had carved their initials into its sides. Someone had cut his punches, and another person, or possibly the same one, had stuck a cigar butt in his vent. Payne stood in the rain for a long time staring at the corpse. He had studied moths; now he has decided to turn his attention to cetaceans.

Aside from the dead, Payne had never seen a whale, nor did he know where whales could be seen. At the suggestion of an acquaintance, he traveled to Bermuda. There he met an engineer who had worked for the United States Navy, monitoring Soviet submarines through microphones installed off the coast. While listening to enemy submarines, the engineer had come across other underwater 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. The sounds – emitted, the engineer had determined, by humpback whales – ranged from mournful moans that sounded like the call of a shofar to high-pitched squeals that sounded like the squeals of piglets. Payne found the tape fascinating and listened to it hundreds of times. Eventually he realized that what he was listening to had structure.

Using a machine called a sound spectrograph, Payne converted the voices on the tape into a series of scribble-like notations. The exercise lasted for years, but he finally confirmed what he had suspected. Humpback whales always made their moans, cries and grunts in a particular order – A, B, C, D, E and never A, B, D, C, E, in Payne’s formulation. The article in which he announced his discovery appeared in Science in the summer of 1971. “Humpback whales (Megaptera) produce a series of beautiful and varied sounds over a period of 7 to 30 minutes, then repeat the same series with considerable precision,” Payne wrote. Each series, he argued, was referred to as a “song”.

While the diary was in the works, Payne arranged to have the Hunchbacks’ songs released as LPs. The album spent several weeks on the Billboard 200 and sold over one hundred thousand copies. It was a particularly impressive feat, as one commentator noted, for a “work without musicians, without lyrics, without danceable beats and indeed without singers either.” (Humpback whales don’t have vocal cords; they make sound by expelling air from their nasal cavities.)” Humpback whales have inspired many land-based artists; Judy Collins incorporated some of their calls into her album “Whales and Nightingales”; Pete Seeger wrote “The Song of the Last Whale in the World”; and the New York Philharmonic performed “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 humpback whales accompanied them. The agency fitted each ship with a “golden disc” that could be played using a stylus (also included) by any alien that intercepted it. The recording featured greetings in fifty-five languages ​​— “Hello children from planet Earth,” the English speaker said — as well as footage of one of Payne’s whales.

When the Voyagers left, no one knew what, if anything, the humpback whales were trying to convey. Today, the probes are more than ten billion kilometers from the Earth, and no one knows it yet. But people continue to hope.

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 out. Instead of pulling out your phone to call an exterminator, you take a moment to think about the situation. The bat, you realize, has no trouble navigating because it relies on echolocation. The owl has such good hearing that it can find the mouse in the dark. The same goes for the rattlesnake, which detects the heat given off by the rodent. The spider is also unfazed by the power outage, as it senses the world through vibration. The mosquito follows the carbon dioxide you emit and lands on your shin. You try to brush it off, but because you’re so reliant on vision, you miss it and end up stepping on the rattler.

Ed Yong, science writer for 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, but not the life-threatening snake encounter.) Yong is interested in what the animals could communicate to us if they could, that is, – 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. Trying to trade a worldview – or, to use the term Yong favors, environment-for another can be frustrating, but, he argues, that’s what makes the effort worthwhile. He reminds us that, “for all our vaunted intelligence,” our environment is just one of millions.

Consider the scallop. (What’s sold at the supermarket’s fish counter is just the muscle scallops use to open and close their shells; the whole animal looks like a fried egg.) Some species of scallops have dozens of eyes. ; others have hundreds. Inside are mirrors, made up of tiny crystals, which focus light onto the retina – the retinas, in fact, since each eye has two. A scallop’s eyes are arranged around the edge of its body, like spikes on a dog collar.

Our brain combines the information collected by our two eyes into a single image. With dozens (or hundreds) of eyes, scallops face a tougher challenge. But they don’t have much intelligence to devote to the task. (In fact, they don’t have brains.) In an effort to figure out what scallops were doing with all their eyeballs, Daniel Speiser, a biologist at the University of South Carolina, developed an experiment that he called Scallop TV. He strapped the animals to small pedestals, planted them in front of a computer screen and forced them to watch images of drifting particles. Scallops are filter feeders, meaning they eat plankton which they filter out of the water. Speiser found that if the computer-generated particles were big enough and moved slowly enough, the scallops would open their shells. “It’s crazy and scary to see them all open and close at the same time,” he told Yong. He thinks their eyes work independently, like motion sensors. When an eye detects something potentially tasty, it sends out a signal to investigate. If Speiser is correct, Yong notes, then even though scallop eyes are both numerous and complex, the animals lack what we might consider vision. They see, he writes, “without scenes.”

“An Immense World” is filled with weird creatures like scallops and weird experiences like Scallop TV. Harbor seals have a fringe of vibration-sensitive whiskers protruding from their muzzle and eyebrows. To assess whisker sensitivity, a team of marine biologists from the University of Rostock, 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 butterflies evade bats, scientists at Boise State University cut off the tails of some butterflies and fitted others with fake wing extensions. To determine if hermit crabs feel pain, two researchers from Queen’s University Belfast poked them with electric shocks, and to figure out the same for squid, a San Francisco state biologist sliced ​​them. with scalpels. When I got to the story of Kathy, a bottlenose dolphin who refused to wear a noise mask that researchers wanted her to wear, I silently applauded her.

The Black Phantom Knife is, as its name suggests, a nocturnal hunter. By pulling a specialized organ in its tail, a knife creates an electric field that surrounds it like an aura. Receivers embedded in its skin then allow it to detect anything nearby that conducts electricity, including other organisms. A 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, but not making contact. No one can really tell, however, since humans lack both electrical organs and electroreceptors. “Who knows what it is for fish? Malcolm MacIver, 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 close enough to humans, Nagel noted, that we believe them capable of what we would call the experiment. But how can we get inside their hairy little heads? The problem isn’t just that they can’t tell us. It’s that their environment is quite foreign.

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

“I want to know what it is for a bat be a bat,” Nagel insisted. “Yet if I try to imagine that, I am limited to the resources of my own mind, and those resources are insufficient. The question “How does it feel to be a bat?” he concluded, is a question people will never answer; it is “beyond our ability to conceive”.

Yong’s response to Nagel, which makes several appearances on its pages, goes along the lines of “Yes, but. . .” Yes, we can never know what it is for one bat to be a bat (or for a knife fish be a knife). But we can learn a lot about echolocation and electrolocation and the many other methods animals use to sense their surroundings. And this experience is, for us, breathtaking. Yong talks to Christopher Clark, a Cornell researcher who in the 1970s worked with Roger Payne, listening to whales. Whale songs are the opposite of bat cries; they are of very low frequency and can travel great distances. If whales use their songs to communicate with each other, they do so not only in space but also in time. A call from a humpback whale near Bermuda would take twenty minutes to reach a humpback whale swimming off Nova Scotia. If the Canadian whale responded immediately, it would take forty minutes before the Bermuda whale responded. To imagine what it’s like to be a whale, “you have to extend your thinking to completely different dimensional levels,” Clark says.

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