The Thing with Feathers (14 page)

Interestingly, flight distance can also be shortened at the opposite end of the spectrum. Urban animals that are continuously exposed to humans, like house sparrows and European starlings in city parks, have become conditioned to us. That’s why urban pigeons will walk right under your feet: They’ve learned that humans aren’t a threat and might even give them some food. It’s also why scarecrows, plastic owls, hawk silhouettes on windows, flapping flags, noisemakers, and other bird scare tactics generally don’t work very well. Over time, birds can become conditioned to almost anything as long as they remain safe.

So it’s the animals in the middle—the ones with some experience of humans, but not too much—that are most afraid of us.

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WHEN THE SEA ICE
at Cape Crozier broke in midsummer, the penguins must have been happy. For months, they had been
commuting miles on foot across the frozen ocean between their nests on land and any crack where they could slip under the ice to hunt fish in the shadowy world below. An overnight windstorm fractured the ice and blew it offshore, leaving large expanses of open water near the penguin colony. The penguins no longer had to walk very far to go hunting.

For the first time, I could watch them dive into the sea, and if I stood with my toes at the edge of the ice and peered straight down, I could even see the penguins swimming underneath my feet through the crystalline water. Below the surface, they compensated for their clumsiness on land. Penguin wings are called flippers for good reason—they help the birds slice through the depths like two-toned torpedoes. I marveled at the long trails of bubbles as each penguin cut and swerved after fish.

The birds were eager to take advantage of their sudden access to the ocean and lined up at the edge of the ice like kids on a diving board. Instead of jumping straight in, though, they would dawdle interminably on the brink. At first, I thought they were being polite, each waiting their turn; they usually formed an orderly bunch with the earliest arrivals at the front.

Then I realized that they were afraid of the water.

Several penguins would line up at the edge and stare downward as if they were searching for something. More would waddle up from behind in straggling groups until dozens of them were standing in a tight, nervous bunch. No penguin wanted to be the first to get its feet wet. The birds in front would scoot sideways and work their way to the back of the group as more piled in from the rear. Eventually, so many of them would be jostling for position, with the ones in the back pressing forward, that some poor penguin at the front would get shoved off the edge. A second after it flopped into the water, an invisible stoplight would suddenly flip green: The entire
group, sometimes a hundred penguins or more, would dive in all at once.

Cherry-Garrard noticed the same behavior in 1911. “They will refuse to dive off an ice-foot until they have persuaded one of their companions to take the first jump,” he wrote, before suggesting that the off-key singing of one of his shipmates, who liked to serenade the penguins with a song called “God Save,” would “always send them headlong into the water.”

This dance was funny to watch, but the penguins had good reason for it. Ten-foot-long, 800-pound leopard seals—the top predator in Antarctica, besides killer whales—sometimes prowl the beach along Cape Crozier in hopes of ambushing an unsuspecting penguin. The birds were wise to be cautious.

If penguins have nightmares, leopard seals probably play a starring role. The seals, recognizable by their large, gunmetal-gray body with a faintly spotted pattern, elongated snout, and devilish grin, have knifelike incisors designed for tearing apart fish, penguins, and other seals. Leopard seals usually can’t catch a penguin on land or in the open ocean, but they have learned that the birds are vulnerable in the shallows as they enter and exit the water. So the seals wait, submerged, like killer submarines just offshore, for an unlucky penguin to jump into their jaws.

Even people are occasionally victims of leopard seals. In 2003, a twenty-eight-year-old scientist working for the British Antarctic Survey was snorkeling near the Rothera research station, on the Antarctic Peninsula, when a leopard seal suddenly appeared, grabbed her, and dragged her sixty feet underwater in front of a group of horrified colleagues. By the time a rescue boat could retrieve her, she was dead.

A member of Ernest Shackleton’s Imperial Trans-Antarctic Expedition in the early 1900s was chased by a leopard seal
until his companions shot it. And more recently, researchers using inflatable boats have had to add reinforcements to prevent punctures because seals have been known to chomp on the pontoons. On a continent where the total human population usually does not exceed 5,000, these incidents seem to occur with somewhat alarming frequency.

Imagine, then, what must pass through a penguin’s mind as it contemplates diving into the water. No wonder it doesn’t want to make the first move. Penguins might not be afraid of us, but when confronted by a cold, dark ocean with invisible lurking danger, they conceivably feel as much fear as we would in the same situation. They have to deal with this threat every time they get in the water, every time they search for food.

This kind of penguin fear has lately caught the attention of scientists. The danger of leopard seals, some suggest, hasn’t just affected the way penguins line up on an ice floe; it might also clarify much larger, more complex aspects of penguin behavior. For instance: Why are penguins afraid of the dark?

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WHEN AN ANIMAL IDENTIFIES
serious danger, its system gets ready to cope—the classic fight-or-flight response. The heart beats faster, the lungs process more air, energy floods into the muscles, bowels give way, and digestion slows. All of these physical reactions help a creature stand to battle, like a buffalo facing off against a wolf, or sprint to safety, like a gazelle running from a lion.

Some of the physical effects of fear aren’t so easy to explain. Shaking, loss of hearing, paralysis, and even fainting can follow a sudden fright, and the wisdom of passing out in front of a hungry predator is debatable. The fight-or-flight mechanism has been criticized for being too simplistic: Many animals have
other reactions when faced with danger, such as employing camouflage (though this could be seen as flight). Fear is not an on-and-off emotion; it encompasses a spectrum of reactions, many of which don’t ignite an emergency physical response.

Researchers have even suggested that males of some species, including humans, evolved different strategies for dealing with fear than females. The fight-or-flight scenario may be male-oriented. Female animals of many species often confront danger by sheltering their offspring and seeking a group of companions, in what is now called the tend-and-befriend response. This difference in the reaction to fear could have evolved in humans when men and women were largely segregated in their work, and has even been theorized to account for the greater life expectancy of women, as the effects of fight-or-flight mentality may be more damaging to overall health. The different responses could also have resulted from more recent cultural conditioning; nobody really knows, but it’s interesting that men and women may confront their fears in different ways.

Still, the fight-or-flight response is common among many animals, and the mechanism is straightforward. It is triggered by the release of stress hormones, including cortisol and epinephrine—also called adrenaline—which cause the physical manifestations of fear.

How the brain decides to release those hormones is complicated. Fear may be one of the most basic and widespread emotions. In the 1980s, the psychologist Robert Plutchik hypothesized an emotional wheel, like the color wheel, which has become influential. Plutchik’s wheel contains eight primary emotions arranged in paired opposites: joy and sadness, trust and distrust, surprise and anticipation, and anger and fear. Like colors, emotions can exist in varying intensity—fear, for instance, ranges from minor (unease) to extreme (horror). By
combining those basic building blocks, Plutchik argued, any secondary emotion could theoretically be formed: for example, submission is fear combined with trust and awe is fear combined with surprise.

Plutchik also believed, along with many others in his field, that emotions evolved because they increase survival—and that animals experience emotions in the same way we do, which is particularly important. The first of ten emotional postulates in his book
Emotion
states, “The concept of emotion is applicable to all evolutionary levels and applies to all animals as well as humans.” This means that penguins may be emotionally similar to us. If that’s true, those of us trying to get inside the mind of a penguin must first understand our own.

Although emotion itself is innate, fear of particular things is regulated by experience. Humans and other animals can learn to fear just about anything under the right conditions, and most conscious fears seem to be learned. The association of specific events with anticipated consequences is called fear conditioning, and experiments have shown that negative reinforcement is a powerful force. In order for a stimulus to result in a response in any animal, all that matters is that the two occurrences coincide repeatedly so that the brain learns to associate them. The most classic example may be Pavlov’s dog; the Russian physiologist rang a bell every time he put food in his dog’s tray and proved that the dog soon salivated at the mere sound of the bell.

In extreme cases, fears can be linked to seemingly random events. A well-known example is Little Albert, a nine-month-old infant studied by American psychologist John Watson, along with his assistant Rosalie, in 1920. According to Watson, Albert was a normal, healthy child with an aversion to loud noises and no inherent fear of white lab rats. In Watson’s experiment, he introduced a white rat to Albert, who was
allowed to happily play with it for a while. Then Watson changed tactics: Whenever Albert reached to touch the rat, Rosalie clanged a hammer into a steel bar just behind the baby’s head. Each time this happened, the infant burst into tears at the sudden noise, and, after several repetitions, he would cry at the sight of the white rat alone. Watson reported that Albert then began to cry in reaction to other things resembling a white rat: a Santa Claus mask with white cotton balls, a furry dog, and a white coat. In a very short time, Albert had learned to be afraid of something benign.

The Little Albert experiment is considered unethical by today’s standards, and it didn’t turn out well for anyone involved. Watson had a scandalous affair with his assistant, Rosalie, divorced his wife, and was kicked out of his university. He never got the opportunity to recondition Albert, who presumably remained terrified of fluffy white objects. But the study inspired decades of research about fear, and John Watson turned the course of psychology toward behaviorist ideas that favored nurture over nature.

Conditioning is mostly a good thing—it allows our brains to know how to respond to our surroundings without analyzing every detail. Even fear conditioning is usually beneficial because it allows us to avoid danger. Some doctors have used the same concept to treat addicts with aversion therapy. The idea is that alcohol paired with, say, a vomit-inducing drug will teach an alcoholic to associate the two and then quit drinking. This technique can be dangerous because it adds more abuse than it eliminates and doesn’t treat the underlying condition, but it sometimes works.

Fear has recently been linked with an almond-shaped part of the mammalian brain called the amygdala, nestled deep inside the skull, which is known to process memory and emotion.
The amygdala probably plays a role in guiding our fight-or-flight response—that feeling you get, for instance, within half a second of a close lightning strike. The reaction is immediate, innate, and, in a sense, unconscious. Fear also gets routed through the cognitive parts of the brain, which take a few seconds to catch up—eventually directing you to run for cover. By the time rational thoughts take over, your body is primed and ready to make an escape. The two pathways—a subconscious, immediate response from the amygdala and a delayed, logical response after the rest of the brain realizes what’s going on—have been nicknamed the low road and the high road.

The separation of these two pathways was nicely illustrated by a brain-damaged woman who suffered amnesia in 1911. She was incapable of reasoning or forming new memories, so each time she visited her doctor, he would have to reintroduce himself and explain why she was in his office. One day, when she entered the room, the doctor shook her hand while concealing a sharp pin in his palm. He then left for fifteen minutes. When he returned, the woman predictably had no memory of who he was or how he had pricked her. But when the doctor reached to shake hands again, she wouldn’t do it. Asked why, she couldn’t explain; the woman merely said, “Isn’t it allowed to withdraw one’s hand?” Although her high-road logic had been damaged, her subconscious low-road response remained intact.

Birds don’t have an amygdala, but researchers have hypothesized that other, similar structures in the avian brain might have evolved to perform a similar function. They certainly react to immediate threats in the same way we do: Frightened birds become agitated, vocalize, freeze in place, or try to fly away. Most examples of fear in birds are of this type of low-road response; once a bird escapes past a certain, ingrained flight distance, it loses all noticeable interest in a predator.

The question of a high-road response to fear in birds is harder to answer, and there is less evidence for it. Think about all the penguins that were clobbered for food by Antarctic explorers in the early 1900s. It was ridiculously easy for Scott and Shackleton to kill all the penguins they could eat—they merely strolled up to the unsuspecting birds and bashed them over the head (though they eventually learned that seals tasted much better, and left the poor penguins alone). Like Darwin’s iguanas and other persecuted Galápagos wildlife, the rest of the penguins never seemed to catch on and remained as approachable as ever despite the repeated murder of their comrades. The birds evidently couldn’t infer that the abuse befalling their friends might also happen to them. Humans in the same situation would probably have learned to avoid the new danger by using an analytic response.