by Ziya Tong
But even if we can’t see it, we can still feel it. Years later, Gulf residents are still complaining of strange symptoms: skin rashes, migraines, nausea, seizures, rashes, bloody diarrhea, pneumonia, muscle cramps, severe mental fuzziness, and even blackouts. To the naked eye, however, the Florida beaches look picture perfect.
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IN THE ANIMAL WORLD, sight comes in other forms as well. Beyond the ability to see heat, see in ultraviolet, and see Earth’s magnetic fields, there’s also the ability to see by means of using sound, or echolocation. Bats and toothed whales evolved this ability independently. Either in the air or underwater, by emitting a series of rapid-fire buzzing or clicking sounds and listening for the echoes, animals are able to determine the shape, location, and movement of objects around them.*8 Bats have an acoustic visual field of about two to ten metres away and can “see” as close as four to thirteen millimetres, which is important for hunting small insects. Common bottlenose dolphins have a biosonar range of about 110 metres, while sperm whales, who hunt squid in the depths of the ocean, have the largest field of view, able to spot prey at 500 metres.
So how do we know that biosonar allows animals to “see”? The first study to look into bats’ ability to fly in total darkness was done in the eighteenth century by Lazzaro Spallanzani. Spallanzani was determined to figure out which sense the bats *9 were using, so he isolated each one—vision, touch, smell, taste, and hearing—and eliminated them one by one.
It is, of course, a myth that bats are blind, but to ensure it wasn’t their sight that allowed them to avoid obstacles in the dark, Spallanzani blinded them, first by covering their eyes with a hood and then, more gruesomely, by removing their eyes. In his notes, he wrote, “Thus with a pair of scissors I removed completely the eye-balls in a bat….Thrown into the air the animal flew quickly, following the different subterranean pathways from one end to the other with the speed and sureness of an uninjured bat. More than once the animal landed on the walls and at the roof…and finally it landed in a hole in the ceiling two inches wide, hiding itself there immediately. My astonishment at this bat which absolutely could see although deprived of its eyes is inexpressible.”
Studies with dolphins—thankfully with their eyes intact—have also led to profound insights about their abilities. Controlled studies on captive dolphins have found that they can recognize distinct shapes by using biosonar alone. Researchers at Kewalo Basin Marine Mammal Laboratory in Hawaii put a dolphin named Elele to the test by placing objects of various shapes inside a box. The box was made of a thin black Plexiglas that was opaque to the eye but could be penetrated by sound. Elele was shown three objects being held in the air by the trainer and asked to identify which one matched the object in the box by pointing with her rostrum to the matching object. She performed exceptionally. Able to switch senses with ease, Elele could “see” what object was inside the box whether she used vision to match the echolocated object or echolocation to match the visible object.
Anecdotally, people have long observed that dolphins are particularly curious about pregnant women and other pregnant dolphins, swimming up and making a buzzing sound near the belly of the expectant mother. While not confirmed, it wouldn’t be surprising if dolphins can “see” right through flesh and into our bodies, as the ultrasound that dolphins use for echolocation is similar to the ultrasound that medical practitioners use to image fetuses.
And what does a “click image” look like? It’s impossible to know. But if anyone could give us a clue, it would be Daniel Kish, the real-life Batman. Blind since he was a baby, he began clicking with his tongue and listening for the echoes as a way of creating a mental picture of the world. It wasn’t until he was eleven years old, when a friend asked him if he was using echolocation, that Kish realized he was doing what bats did in order to “see.”
While humans don’t have a bat’s fine-tuned abilities to detect small, quick movements, Kish has developed some remarkable sensitivities. He can hear buildings, and in a click “see” whether they are ornamented or plain and featureless. In an auditorium, he can hear the exits, and he usually knows where they are before a sighted person spots them. He rides his bicycle around the city using only his ability to echolocate. Researchers studying Kish’s brain activity using MRI have found that the area of the brain being activated when he echolocates is the region typically devoted to vision. What that tells us is that his brain registers sound as sight. He not only hears sound, he “sees” it.
Few of us will ever know what it’s like to see like Daniel Kish. But knowing what we don’t know tells us something. Kish inhabits a sensory world as unknowable to us as a bat’s or a whale’s. It is the same world as ours, and at the same time it is completely alien to us. Yet Kish is unquestionably human. Which tells us that while the way our fellow animals see the world may seem exotic or alien, there is no sense in which we could reasonably believe it’s inferior.
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THE SENSE OF SIGHT is not only singular however, it is communal in that it allows us to mimic and learn from others. Children watch adults intently to copy what they do, and the same is often true of animals. This is why, using sight, a bee with a brain the size of a sesame seed can be taught to do something it would never naturally do in the wild: it can learn to play soccer.
Using a plastic bee attached to the end of a stick, researchers at Queen Mary University of London first showed the trainee bees what to do. The bumblebees watched as the fake bee pushed a small ball into a circle. This was the “goal.” When the ball was manoeuvred inside the lines, the insects were given a sugar-water treat. After three observation trials, the trainee bees were then placed in the miniature stadium. Just by watching the fake bees, they were able to mimic the unnatural task, scoring a goal themselves 99 percent of the time.*10
Sight is also key to visual memory. And the animal with the most jaw-dropping visual memory known to science, is Ayumu, a chimpanzee who lives at the Primate Research Institute at Kyoto University. What makes Ayumu special is that he has an eidetic, or photographic, memory. In less than the blink of an eye, his mind can absorb a full scene, and going head to head with a human on a visual memory task, he will win every single time.
On the surface the task is straightforward. It looks something like this: picture the numbers 1 to 9 placed in a jumbled order in random places on a screen. All nine numbers flash up at the same time and are held there for just over half a second. After the numbers flash off, blank white blocks light up where the numbers were and remain in their place. The task is to tap, as fast as possible, in correct sequence, the white blocks where the numbers from 1 to 9 previously appeared.
To watch Ayumu do it is stupefying. Even after looking at the screen for several seconds, a human finds it hard to process the placement of just a few numbers, let alone all nine. In a test against British memory champion Ben Pridmore, who can memorize the order of a shuffled pack of card in less than thirty seconds, Ayumu was the clear winner. Pridmore had an accuracy of only 33 percent, while Ayumu was correct 90 percent of the time. But for Ayumu, even half a second is a considerable amount of time: he’s been able to succeed in this memory task after seeing the images for just 210 milliseconds.
So how is he able to do this? We know that, in general, chimpanzees are better than we are at something called subitizing, which is the ability to see and instantly know the number of objects in view, similar to how you can see the number 4 on dice without having to count the dots. While humans can subitize up to four or five random numbers, chimpanzees can subitize upwards of six. Ayumu is particularly good at this, even for a chimpanzee. He outperforms both humans and chimpanzees, suggesting that his visual memory is outstanding.
Animals do not just process what they see like automatons, of course. They are active agents. And like humans, they communicate what they see in the world around them. And while almost all communication occurs within species, some scientists have ventured a
cross boundaries and are learning to see through animal eyes by teaching them to communicate with us.
The most famous communicator from the avian world was an African grey parrot named Alex. Selected at random from a pet store, he was reared by researcher Irene Pepperberg and became so well known for his abilities that he revolutionized our ideas about animal intelligence.
Although Alex had a brain the size of a walnut, he had the cognitive abilities of a five- to six-year-old child. Pepperberg trained Alex to answer questions about what he saw. He was shown objects and taught the words that described them. While parrots don’t have a larynx with vocal chords, they do have a syrinx, allowing them to mimic the sounds of human speech. Alex could identify different shapes and colours and count to eight; he knew the difference between “same” and “different,” and “bigger” and “smaller”; and he could communicate with more than a hundred words.
Alex would also come up with labels for novel things he encountered. In the process of being taught fruit names, for example, he surprised the researchers. He already knew the words “banana,” “grape,” and “cherry,” because he learned the names of the fruits that he was fed. But when he saw an apple for the first time, the bird had his own word in mind. He insisted on calling it a “banerry.” Why? Well, it’s possible that Alex saw it was red on the outside and yellow in the middle, or he tasted it and decided to use a combination of the two fruits he already knew: a banana and cherry. Either way, “banerry” it was, because from then on he refused to call it an apple.
Alex is also the only animal known to have asked a question about himself. In December 1980, he caught sight of his reflection in a bathroom mirror. Turning towards it, the parrot asked his handler, Kathy Davidson, “What’s that?” Kathy replied that was him, Alex, and that he was a parrot. After studying himself for a while longer, he asked, “What colour?” Kathy said, “Grey. You’re a grey parrot, Alex.” After a back and forth that went on a few more times, Alex, it seems, finally understood. According to Pepperberg, that was how Alex learned the colour grey.
This ability to describe the visual world is not unique to parrots. Other animals have learned to communicate with us as well. Perhaps most famous was a gorilla named Koko. Using a modified version of American Sign Language (ASL), Koko had an extensive vocabulary: she was able to sign over one thousand words and understood over two thousand words in English. Like Alex, Koko was known to come up with words for new things that entered her environment. The first time she saw a zebra, for example, she described it as a “white tiger”; a Pinocchio doll was signed as “elephant baby”; and the first time she saw a ring she called it a “finger bracelet.”
It should be noted that scientists still rigorously debate whether animals like Koko and Alex truly had the ability to communicate. That’s because science demands strict objectivity in verifying results, but language is subjective and, as we all know, often ambiguous. When it comes to studying animal intelligence, scientists often rely on a principle called Morgan’s Canon. Essentially, it states that one should not ascribe higher psychological processes to an animal if the same behaviour can be attributed to something simpler, like an error.
Eugene Linden, the author of Apes, Men, and Language, describes the same situation with Washoe, a chimpanzee, and the first ape to learn ASL: “About 50 years ago, on a pond in Oklahoma, Washoe saw a swan and made the signs for ‘water’ and ‘bird.’ Was she simply noting a bird and water, or was she combining two of the signs she knew to describe an animal for which she had no specific word? The debate continued for decades and was unresolved when she died.”
There may be one way to settle the debate, however, and that’s by controlling for the environment that animals are being questioned about. In Norway, scientists came up with a clever way to do this by training horses to communicate with symbols. The task was simple: the horses were trained to use their muzzles to point at a board, indicating whether they wanted to wear a blanket. A vertical bar meant “take the blanket off,” a horizontal bar meant “put the blanket on,” and a blank symbol indicated “no change” as their preference.
After just two weeks of training the animals for fifteen minutes a day, they were able to use the signs to communicate. The horses were not simply discriminating between the visual cues; they were making their decisions based on the outside weather. On warm days, when the temperature was 20°C to 23°C, all ten of the horses given blankets requested that the blankets be taken off. The horses that did not have blankets on, signalled that they wanted their state unchanged. On rainy, cold days, when the weather was 5°C to 9°C, all ten of the horses with a blanket on signalled that they wanted their state unchanged, whereas ten of the twelve horses not wearing blankets requested to have one put on.
That twenty of the twenty-two horses wanted a blanket on cold days suggested to the researchers that the horses did indeed understand the visual symbols and were making requests. As for the two holdouts, on colder testing days, where the temperature ranged from –12°C to 1°C, the outliers gave in and joined the rest.
While these “talking horses” are impressive, the world’s best animal communicator, at least when it comes to using visual symbols, is Kanzi, a male bonobo, who lives at the Great Ape Trust in Des Moines, Iowa. Kanzi has a five-hundred-word vocabulary in the form of touch screen symbols called lexigrams, he understands over three thousand English words, and is said to comprehend complete sentences and instructions.
Wearing a welder’s mask so that her facial cues or eye movements didn’t give anything away, Kanzi’s trainer Sue Savage-Rumbaugh conducted tests by coming up with novel sentences and bizarre requests to see exactly what Kanzi understood. Asked to put salt on a ball, Kanzi promptly took the salt shaker and did as requested. When Savage-Rumbaugh asked Kanzi to put pine needles in the refrigerator, Kanzi again had no problem performing the task. Asked to carry the TV outdoors, Kanzi got up, looked around, spotted the television set, and immediately carried it outside.
To understand just how astonishing this is, pause to consider what Kanzi might have been thinking. Many humans have difficulty picking up a foreign language. These animals are dealing not only with a foreign language but the requests of a foreign species. If Kanzi is smart enough to learn what many of us cannot, it’s not implausible to imagine that he may have wondered why Savage-Rumbaugh would want to refrigerate pine needles in the first place. What might he be making of the human in front of him before getting up and, once again, complying?
At this point, it’s fair to ask: if bonobos and chimpanzees can do it, can we? Seals and dolphins understand our hand signals, dogs and elephants understand our vocal commands, orangutans can even use iPads to communicate with us. But what do we understand about other animals’ languages? What are they seeing and describing in their own tongues? As science journalist Rachel Nuwer has observed, in trying to “force apes to learn our language, we may have blinded ourselves to theirs.” To find out, one man has spent much of his academic career taking the time to flip the script, and in doing so he has opened up a whole new way to examine how animals communicate on their own terms. His name is Con Slobodchikoff, and he has been called a modern day Doctor Dolittle.
Slobodchikoff, an emeritus professor of biology at Northern Arizona University, works with Gunnison’s prairie dogs, highly vocal little animals that look like North America’s version of meerkats.*11 Peeping their heads up from their burrows, the prairie dogs are often on high alert for predators. Noting that they give off alarm calls, Slobodchikoff began recording the sounds they made when they saw different predators approach. To our human ears, the calls for the most part are the same: short barks in quick succession that sound almost like they are coming from a squeaky toy. But a computer analysis revealed something else: each call was unique. And by visualizing the sound waves of the calls in a sonogram, Slobodchikoff could see that the barks for the different predators were clear and distinct.
Barks for “human,” “hawk,” “coyo
te,” and “dog” all have signature acoustic sonograms with differing wavelengths and amplitudes. And despite some of the predators looking similar, the prairie dogs never bark “dog” when they see a coyote, or vice versa. For Slobodchikoff and his research team, the sonograms were a way to decode the rodents’ communication, like a prairie dog Rosetta stone.
So how can we be sure that the calls mean what we think they do? Slobodchikoff and his research team not only recorded the prairie dog alarm calls but also video recorded their escape responses. Upon seeing a hawk, the animals would look up, make a quick one-syllable bark, and scurry down to their burrows. An audio playback of the prairie dogs’ “hawk” bark would elicit the same response: they would look up and search in the sky, then run towards their burrows. When the sound of a dog was played, however, the prairie dogs would stand on alert but not run away.
Robert Seyfarth has done similar work with vervet monkeys. The primates have different alarm calls, or “words,” for hawks, snakes, and leopards. The monkeys respond to the “leopard” call by running up a tree, but on hearing the alarm call for “hawk,” they looked up in the air and quickly sought safer ground by hiding in a bush. They avoid climbing trees during “hawk” calls, presumably because in a tree the raptors catch them. The calls are clearly meaningful among the troupe. When a vervet monkey makes an alarm call for “snake,” the primates all stand on their hind legs and begin scouring for signs of the predator lurking in the grass.