How Animals Grieve (8 page)

A third bunny came into foster care also, but this one preferred people and wanted nothing to do with other rabbits. Majic had been a classroom bunny for five years. That might sound like a fairly good life for a rabbit, but as we discovered ourselves when we adopted Caramel from the Montessori school, even well-meaning schools can offer inadequate resources. Majic’s cage was small, too tiny even for him to properly clean his ears. It had a wire floor, which is hard on rabbits’ feet, which lack the thick pads that cats’ and dogs’ feet have. And having excitable children surrounding one’s cage can’t be the most restful experience. Eventually, Majic began to lash out at children who put their fingers into his cage.

When he arrived at foster care, Majic suffered from a bad ear infection, molars in such poor shape that he couldn’t eat properly, and nerve damage in his feet from a declawing procedure. Curing Majic’s ear and dental problems wasn’t all that hard. The nerve damage, though, meant he couldn’t jump well. He began to relax around people and even to enjoy cuddling, but he acted defensively when put with other rabbits. He was kept isolated, in a house with thick, comfortable sleeping material, in
the
same room as Trixie and Joey. A perimeter was set up around his bed to make sure the other rabbits kept out, but no latched gate was deemed necessary because Majic made no effort to get out on his own.

For two years, Joey and Trixie enjoyed their friendship. Then, Joey began to lose weight and his health worsened. He suffered a seizure. Joy and her husband consulted with a veterinarian, and they all agreed it was time to let Joey go. He was euthanized, and at the vet’s, Trixie was allowed to stay with his body for a while.

Back home with Joy, Trixie was sad. She didn’t eat and, Joy recalls, she “made a small and pathetic picture as she lay in her empty house.” The next morning, though, Joy viewed an unexpected scene: Majic had jumped down from his bed and the two rabbits lay close to each other, prevented from close contact only by the door of Trixie’s house.

After settling Majic back on his bed (for the sake of his damaged feet), Joy opened up a channel between their houses. For two days, Trixie shuttled back and forth between the two “home turfs,” and then she moved in with Majic. By the third day, the new friends were cuddling and grooming, and Trixie once again was eating well.

Trixie was one of the lucky ones, just as Vincent had been. Some rabbits don’t come out of it so easily. Rabbits, like many other animals, may fall into serious depression when they mourn. In extreme instances, they may even starve themselves to death.

Just as I was exploring the nature of severe depressive responses to grief, Karen Wager-Smith sent me a paper on the neurobiology of depression that she wrote with Athina Markou. Focusing on a wide variety of animals, including humans, Wager-Smith and Markou ask whether an understanding of the dynamic brain might cue us in to adaptive aspects of acute depression, the type that’s both symptomatically intense and relatively short in duration. The two scientists posit a chain of events that culminate in a person’s experience of acute depression. The trigger is some kind of stressful life event. Perhaps a person loses her job or faces an unwanted divorce. Or he may be sent for repeated tours of combat or lose his partner to death. Studies show that about three-quarters of initial depressive episodes are preceded by major stress of this kind.

What happens next occurs at the neurophysiological level. The dynamic nature of the brain means it’s time to jettison old assumptions
about
an organ that remains fixed and static in adulthood, after a period of growth and adaptation during one’s younger years. In fact, our brains always grow and adapt at the physiological level. Each of us sees, thinks, and feels our way in response to events that occur (or that we create), and as we do, our brains rewire. In tandem with our experiences, neurons are strengthened or fall away. Some of the neural pruning that goes on, we might initially think of as negative: a loss of brain tissue, after all, doesn’t sound welcome. That’s where the second step in Wager-Smith and Markou’s sequence comes in.

Wager-Smith and Markou describe types of “microdamage” that stress may inflict upon the brain and that reduce key neuronal connections in certain regions. Data from animal models suggest that in two brain areas, the hippocampus and the prefrontal cortex, synaptic material may be reduced in the aftermath of stress. Because the hippocampus deals with memory and emotion, and the prefrontal cortex is a center of planning and personality, it’s clear that such damage, even if limited, could affect an animal’s perception of the world. And it’s not only that animal models predict changes in people’s brains because of stress. Recent studies in brain-imaging suggest a causal relationship between long-term depression and shrinkage of certain brain regions in people, most clearly the hippocampus.

But just as our body rushes to respond when we experience trauma to a limb or infection in an organ, the brain acts to protect itself from the insults of stress. The next step in the chain is brain repair, kicked off when the micro-damage triggers an inflammatory response. And just as there may be short-term negative consequences during recovery from trauma or sickness, in the period after the brain-shock of stress, a person may feel fatigued, sleep more, and eat less. When the brain is involved, there’s the likelihood of something extra, too—a tendency to feel acute emotional pain. Wager-Smith and Markou think that the inflammatory response may cause a kind of hypersensitivity to psychological pain.

In many cases, this hypersensitivity is of limited duration; as the repair mechanisms do their job, the mental anguish begins to fade. Unfortunately, though, the pain doesn’t always diminish. For some
people,
acute depression, a response to a stressful event, settles in, in a soul-crushing way. Systems as complex as the human brain are prone to highly variable outcomes depending on a web of factors—from genetic predispositions to family patterns, from personality traits to access to resources that might bolster one’s ability to cope. If for some reason the hypersensitivity to mental pain becomes entrenched, a person may fall into the “unrelenting pain” of extended depression that William Styron describes in his memoir
Darkness Visible
.

The synopsis I’ve just provided only summarizes a detailed hypothesis. In their article, Wager-Smith and Markou present neurobiological evidence to support each step in this proposed chain. Because its explanatory power is rooted in both biology and culture, this model of human adaptation is of a type that anthropologists like me admire. It takes into account lived experience as much as aspects of physiology and genetics. Again, it’s not just that the brain shapes our responses to what happens around us, but that what happens around us sculpts our brain, and continues to do so throughout our lives.

Within limits, then, a depressive response to severe stress may be beneficial. When a person or other animal is shocked by a life event, it may benefit that individual for the brain to stage a mini shut-down. The sufferer thus gains time to recover emotionally. The new neuronal connections may, in Wager-Smith’s phrase, “mediate new behavioral strategies” for the individual as she tries to move past the stressful event.

This model is a significant addition to previous theories, concisely reviewed by John Archer in his book
The Nature of Grief.
Archer notes that in evolutionary terms, grief may be maladaptive, compromising an animal’s capacity for survival and reproduction. A grief response may be a sort of exacerbated separation response. The separation response, which occurs when two animals who matter to each other find themselves apart for some reason, involves distress, protest, and behaviors directed toward reuniting with the lost partner. As such, it may increase the chances of reunion and thus be adaptive. In some cases, a grief reaction may ensure that a partner in a separated pair doesn’t too quickly turn to a new mate, when the missing animal may yet return. In other cases, there is no apparent benefit; grief then may be just a natural, highly
elaborated
by-product of the separation response or, more broadly, of the animals’ close bonds.

Archer does discuss depression as it relates to grief, but Wager-Smith and Markou’s model goes further, explaining more precisely why it may not be pathological for some animals to exhibit
severe
grief at the death of a friend or partner. If stress has rewired an animal’s brain, a period of altered sleeping and eating may conserve energy in a way that aids psychological as well as physical healing. The sadness—indeed, mental agony in some cases—is the “extra” that comes with this brain stress. As Wager-Smith told me, “Grief is an evolved behavioral program, akin to sickness behavior, that promotes convalescence during a significant neural rewriting job.”

Perhaps, when a survivor pairs up with a new partner, the brain-repair process accelerates, allowing for quicker recovery. We have seen, with the rabbits Vincent and Trixie and with other animals, that a new social stimulus may snap an animal out of lethargy. In proposing a causal link between acquiring a new partner and a “kick” to brain recovery, I’m only speculating. Wager-Smith and Markou’s model itself may prove right or wrong in its details, or even in its major points. It’s the way of science, and an elegant one at that, to propose some explanation, multistepped and intricate, that must then be tested, by its authors and others, as they gather more data.

Surely there is no single, overarching explanation for all episodes of depression in people or other animals. Yet the beauty of Wager-Smith and Markou’s model lies in a reminder it offers: Because death and mourning surely count as one of life’s most stressful events, there may be a common biological underpinning to the grief that animals—horses, goats, rabbits, cats, dogs, elephants, chimpanzees, and people—feel. To make this suggestion is not to say that we are hard-wired creatures whose brains all respond in identical ways. It is, rather, to take seriously the notion that we mammals share some tendencies in our biology and in the ways our life experiences may affect our biology. Though based on that common platform, outcomes will—because of species-specific behaviors, different developmental histories, and individual personalities in complex combination—be variable, both across and within species.

Meanwhile,
I like to think of rabbits as “iceberg” animals in the world of animal grief. Bunnies—like the chickens and the goats I discussed in the prologue—are not the animals people first think of when considering nonhuman grief. They are the tip of the iceberg because they point us toward a future time, maybe not too long from now, when the fact of animal mourning across diverse species will be taken as common knowledge.

5

ELEPHANT BONES

When elephants grieve, the emotion may stream from those huge, wrinkled-gray bodies in palpable waves. If you are close enough, you can feel it in the air.

Animal-behavior expert Marc Bekoff went to northern Kenya with Iain Douglas-Hamilton, one of the world’s top elephant scientists, and was startled when he first spied the massive creatures. “Their heads were down,” Bekoff reported, “ears dropping, tails hanging listlessly, and they were just walking here and there, moping around, apparently broken-hearted.” He first felt the elephants’ emotion, then learned from Douglas-Hamilton that the herd’s matriarch had recently died.

As the two scientists continued their drive, they came upon a second group of elephants only a few kilometers away. Here the scene was much different. These elephants looked content. With heads up, ears up, tails up too, they exuded a sense of well-being.

That the first, sad group was in mourning—and not just a bit disorganized after the loss of their leader, or momentarily upset about some other matter—we can pretty much assert as a fact. Example after example of mourning by elephants who have lost one of their tightly bonded group has been reported by scientists. It’s the closest thing we have, in the nascent world of animal-grief study, to scientific certainty. In this way, elephants are a touchstone species for understanding how wild animals grieve.

Douglas-Hamilton’s own years of elephant study prove the point. Since 1997 his research team has monitored the population at Samburu
National
Reserve in Kenya, where nine hundred elephants are known as distinct individuals. (This feat is impressive. At Amboseli, in southern Kenya, it took real effort for me to learn reliably the identities of just over a hundred baboons.) A year later, GPS technology was added to the scientists’ arsenal, so that radio-tracking data now supplements direct observation of the elephants.

At Samburu, as in other elephant populations, the females and their young offspring form tight units; female kin and favored associates tend to stay together, or break up into smaller units that reunite into a herd at regular intervals. Most of the year, the mature bulls roam independently, approaching the herd only to mate with fertile females.

Judging from a fantastic discovery in 2011, prehistoric elephants organized themselves in just this way too. Distributed over a large area of desert in the United Arab Emirates, and studied in part from the air because of its sheer size, is an ancient “trackway” of elephant footprints. These footprints, which at first glance appear to be mere depressions in the earth, tell us that at least thirteen elephants of varying sizes and ages walked together seven million years ago. Separately, there walked a much bigger elephant. If, as scientists suspect, this separate animal was a solitary bull, the footprints amount to a prehistoric blueprint for the social organization of elephants today.

The geometry of the dual fossilized paths is telling. The narrow trajectory of the footprints of the thirteen animals suggests that these elephants moved in concert. The lone elephant’s footprints transect those of the herd, meaning that he was moving in an almost perpendicular direction. Paleontologist Faysal Bibi described the footprints to the BBC as a “beautiful snapshot” of the social behavior of a now-extinct ancestor of today’s elephants.