Nobody feels cuddly about crows. They're too big, too loud, too mean. They scavenge with the greed of buzzards, prey without the grace of eagles and even chase down children who come too close to their nests. They are the dark symbols of human mythology--portents of plague, of sorcery, of evil. There's a reason the proper term for a flock of them is a murder of crows, and it's not because we like having them around.
But there's something deeper going on in the soul of a crow. An animal that inflicts death so readily seems deeply moved when one of its own kind dies. A dead crow lying in the open will quickly attract two or three other crows. They dive and swoop and scold--emitting a very particular call that summons up to a hundred other members of the flock. With near ceremonial coordination, they land and surround the body, often in complete silence. Some may bring sticks or bits of grass and lay them next to--or even on top of--the remains. Then, tribute paid, they turn and fly off.
"They seem," says University of Washington wildlife scientist John Marzluff, "to be mourning a loss."
That, it hardly needs saying, is not what we expect. Human beings have fixed ideas about the hearts and minds of beasts, most of them not very flattering. Animals are simpletons on the whole, sometimes capable of impressive flashes of cleverness and a kind of wagging, nuzzling, tongue-lolling love. But abstraction? No. Empathy? No. Even a rudimentary sense of the arc of life and their mortality and the great wrenching loss that is death? Please.
And yet the fieldwork says otherwise. There are accounts of chimp mothers that refuse to surrender a baby that has died, holding the body for days or weeks after it has gone cold and begun to decompose. There are elephants that stay by the body of a fallen herdmate long after a death--examining, touching, attending--or stop to caress and examine elephant bones they find. There are dogs and cats that languish and refuse food when a playmate dies, the cats expressing their grief with a terrible keening cry. Bonobos rage, rage against the dying of the light, sometimes throwing rocks at a dead troopmate and pounding its chest in frustration before pounding their own. Apparent sorrow following a death has been observed on the farm--among goats, pigs, ducks--and in the oceans as dolphin mothers, like primate mothers, push the bodies of their dead young in front of them.
It's impossible to look at this behavior and not see something that's an awful lot like mourning, and yet science, in its own way, rages against all of it. For every seeming grief ritual, it's possible to posit a cold, adaptive purpose: sorrow may simply be fear of the predator that killed a friend; rage may be an attempt to repel the same killer. And without the aid of self-reporting, which is a pillar of human psychological research, it's anthropomorphic in the extreme to presume to know what's going on in the heads of animals. Science's complaints are legitimate--and they miss something too.
Animals are social creatures just like we are. They form relationships that for them are every bit as important as ours are to us, which means that at some point they must experience the end of them. "They're bonded like us," says Barbara King, professor of anthropology at the College of William and Mary and author of the new book How Animals Grieve. "We're all socially attuned, and in many ways our brains are even wired similarly. Why wouldn't animals mourn?"
If they indeed do so, the mechanisms at work may be the evolutionary precursors of our own grief process. "It's easy to see why these rituals would have evolved," says Marc Bekoff, professor of evolutionary biology at the University of Colorado. "It's a wake. They're reinforcing the feeling that things will be O.K., just like grieving human families tell themselves the same thing."
Bekoff and King are among the leaders of a growing group of researchers exploring the question of whether animals mourn. It's not one that can be answered empirically yet--no conclusive lab tests or brain scans exist, though some preliminary ones do. It's dependent instead on the growing body of observations pouring in from researchers in the field, from wildlife managers at zoos and even from pet owners, all struck by the pained and poignant behavior of the animals around them. The beasts, it seems, are suffering--and in ways we recognize well.
The Methods of Mourning
Grief, like animals, comes in multiple species, and as with so many things, it's the human variety that's the most complex. For us, the loss of a loved one inflicts a pain like no other. "Gut me," King quotes journalist Roger Rosenblatt writing in a book about the death of his adult daughter. "Slice me down the earth's meridian from north to south. Lay my bones outside my skin." It's a terrifying description as much because of its visual awfulness as because of the fact that it captures the experience. The rituals we build around that torment--the gathering in rooms, the bowing of heads, the paradoxical laughter at the wake, often with the deceased as the foil--medicate the pain and ease the passage.
No one pretends that grief in animals is anywhere near as complex. For starters, they don't have the brainpower for the long reflection and obsessive remembering that makes grieving such a slow process for us. More important, they couldn't afford to indulge it even if they did. "Most animals are preoccupied with surviving," says Marzluff, who is also the co-author of Gifts of the Crow. "Mother Nature is harsh, and if there's value in dealing with a death, there's also value in moving beyond it quickly, otherwise you're going to get weeded out."
Instead, what researchers point to in identifying animal grief is a suite of observable behaviors familiar to anyone experiencing loss or depression--listlessness, lack of appetite, weight loss. "I'm looking for something prolonged, something visible," says King. "I don't think it's productive to ask if animals really understand death, since there's no way we can know that. I'm just interested in what we can see."
There's no shortage of behaviors that fit that description. By most measures, the animals that seem to experience death in the most humanlike way are not the ones that are genetically closest to us--the great apes--but elephants. The literature has long been rife with reports of the funeral rites and almost reverential treatment of remains that occur among elephant herds. British zoologist Iain Douglas-Hamilton was particularly struck by the 2003 death of an African elephant known as Eleanor at a national park in Kenya.
Eleanor was the matriarch of her herd and had given birth less than six months earlier. Suffering from an illness, she collapsed in the presence of another female. That elephant, known as Grace, trumpeted, nudged Eleanor and tried to push her up with her tusks. As Eleanor died the next morning, another female, Maui, approached and stood over her, rocking and examining her. For a full week, Eleanor's baby and the females of the herd visited the remains. They kept coming after park workers had removed Eleanor's tusks to discourage poachers; they came too after scavengers had begun to eat the remains. The baby nuzzled her mother's body and tried to nurse from the other young calves. But the milk never came, and her mother never moved--and the baby soon died too.
"I see so clearly the emotional ripple effects of Eleanor's death," says King. "I wouldn't want to say every single elephant who approaches Eleanor is grieving: some may be simply curious. But the extreme distress Douglas-Hamilton describes telegraphs to us across species lines."
The great apes approach things differently. One reason may be that their superior brainpower allows them to grasp the permanence and inevitability of death in a way other animals don't. Primatologist Frans de Waal, director of Emory University's Living Links Center, points to a scene he observed when a troop of bonobos encountered a poisonous snake known as a Gaboon viper. The bonobos approached the viper only closely enough to poke it with a stick until a female seized it and flung it onto the ground, killing it. In a blink, the feared animal became a benign object, with young bonobos even examining its fangs and wearing it like a reptilian lei.
"None of them expected it to come back to life," de Waal says. "Dead is dead."
That awareness, which hits grieving humans in terrible waves of existential permanence over the course of months, makes things harder for apes too. At the Burgers' Zoo in Arnhem, the Netherlands, an adolescent female chimpanzee named Oortje contracted an infection that was not responding to medication. One afternoon when the animals were in their indoor enclosure, Oortje seemed particularly sickly, and another female approached her and stared into her eyes, then broke out into screams and began pounding herself on the chest. Oortje tried to vocalize back but toppled over and died. A scream erupted from another chimp, and then all the animals in the large enclosure grew completely still.
It defies science to say with certainty that the chimp closest to Oortje knew that death was coming, but it defies intuitive observation to say otherwise. "The death of Oortje and of the snake suggest that death of others is on the minds of primates and affects them deeply," says de Waal. "Evidence suggests that they know that once an individual has become immobile for a length of time, hope for revival is dim indeed."
Just Say No
Dim hope is not the same as no hope, and humans exhibit a desperate denial of death all the time. Family members in emergency rooms implore doctors to keep heart-shocking and chest-pounding accident victims long after life functions have quit. Psychics and Ouija-board makers owe their livings to our stubborn refusal to accept the dead-is-dead dictum. Religion, too, is a reflection of that. There's a lot more to the study of divinity and the deep faith of believers than just a desire for eternal life, but that's still part of religion's appeal.
Among animals, this behavior seems best expressed in the strange practice of corpse carrying. Chimps, bonobos and baboons carry their dead babies even after the telltale smell of decomposition--to which animals are usually well attuned--has begun and the babies have started to mummify in their hands. It's maladaptive in the extreme to trudge through a jungle where predators lurk carrying several pounds of what is literally dead weight, and yet mothers take the risk and expend the calories all the same. In one case in Guinea, a mother carried her baby for an astonishing 68 days.
"We see this a lot," says Vanessa Woods, research scientist and author of Bonobo Handshake, who worked at a 75-acre (30 hectare) bonobo sanctuary outside Kinshasa in the Democratic Republic of Congo. "Mothers not only carry dead babies; they're very careful with them. Human mothers who stop breast-feeding early have a higher risk of depression, so maybe something similar happens with bonobos when a baby dies."
King's book tells similarly poignant tales of grief and denial across the animal kingdom: There's Willa, the Siamese cat that spent her days wandering from room to room in her home, visiting and revisiting the places her recently deceased sister Carson used to be found. There's Hachiko, Japan's legendary Akita whose grieving appeared to extend across species lines. Hachiko accompanied his owner to a Tokyo train station each morning to see him off for work and then returned in the evening to greet him. When the owner died, the dog maintained his vigil, going to the station day after day for a decade--and always plodding home alone. There are horses that lapse into apparent depression after a companion dies and even a rabbit that, after its cagemate died, "spent about a week doing tragic sweeps of the house, searching for her," according to its owner.
To the extent that it's possible to suss out scientifically what's going on in animals' heads at moments like these, preliminary evidence suggests that it's a grief response. Stress--including the kind that follows a death--leads to the release of the hormone cortisol in animals and humans; cortisol, in turn, can trigger the release of oxytocin, often called "the cuddle chemical." It's oxytocin that spikes in parents after a baby is born and nudges all of us in subtler ways to seek social connections and affiliation.
Primate investigator Anne Engh followed baboons in Botswana to determine how they reacted to one of the most traumatic events an animal community may experience: the killing of one of their own by a predator. After an attack, she would collect fecal samples from members of the troop and look for signs of increased glucocorticoid (GC) stress markers. For up to a month, GC was elevated in all the individuals she tested that had witnessed the killing but was higher still in the 22 that had close family or social connections to the victim. If this led to oxytocin release, the animals would be pushed to engage in the same kind of curative gathering we practice after a death. It's stress plus grieving with a purpose--exactly how the system is supposed to work.
"Even though they may not be aware of the responses, the responses are adaptive," says University of Pennsylvania biologist Dorothy Cheney, co-author of Baboon Metaphysics and one of the researchers who oversaw Engh's work. "As with people, animals with strong social-support networks are buffered against the effects of stress."
Brain studies strengthen the case for animal grief. In humans, mourning is mediated by the frontal cortex, the nucleus accumbens and the amygdala, a deeply seated structure that processes emotions. We share that basic anatomy with many other animals, though in some species the structures are poorly developed. Birds' brains don't parallel ours closely, but they do have an amygdala, and crows in particular have a large forebrain and a well-developed hippocampus, which processes memory.
Marzluff has conducted studies in which crows are captured by a researcher wearing a mask and then fed and cared for by someone wearing a different mask. Later the birds are injected with a radioactive dye and shown either the capture mask, which has stressful associations; the feeding mask, which has pleasant ones; or a third mask they've never seen, which has no associations at all. The birds are then anesthetized and placed in a PET scanner, which reads the location of the dye in the brain.
Consistently, the crows looking at the scary mask have higher amygdala activation than the others. When the experiment is repeated but they are shown a taxidermied crow that appears to be dead, activation occurs in the hippocampus instead, suggesting that they're forming a location memory that says, effectively, This is a dangerous place; avoid it. What Marzluff would like to determine is whether crows would show emotion-laden amygdala activation as well as hippocampus activation if the dead animal they were looking at were an offspring or a mate.
"Crows form lifelong pair bonds and might be mated for 20 years," he says. "When one dies, we've seen the survivor just standing above it looking at it." Killing a mate to run such an experiment is outside the bounds of decency and ethics. But anesthetizing one to simulate death, conducting the test and then reviving and releasing them both is something Marzluff would consider. "As stressful as that would be, it might be worth it to determine if the animals are experiencing what we do," he says. (The crows, surely, might differ.)
Is It the Real Deal?
Compelling as the lab work and field observations are, even advocates of animal-grief theory are wary about concluding too much. King questions whether bonobos or any other monkeys really do grieve, despite what the GC traces suggest. Yes, female baboons may carry dead babies for extended periods, but they have also been seen mating at the same time--hardly consistent with paralyzing grief. "Could this be natural selection pressing her not to grieve openly because it would affect her status, or was she really feeling nothing?" King asks. "I can't say."
The behavior of baboon babies may be less clear than it seems too. They have been observed standing over their dead mothers, rocking and crying, which sure looks like grief but could also be mere hunger. When Mom dies, the milk source is cut off, and lack of food can make a baby not just hungry but also cold, which it addresses by rocking.
Crows may indeed be mobbing a corpse to pay respects, or they may simply be trying to learn what killed it so they won't wind up the same way. And as for covering the body with grass or twigs? In many species, the same death odor that baby-carrying primates ignore triggers disposal behaviors, which protect survivors from remains that could be diseased. Cats apparently searching from room to room for a dead companion may just be trying to get used to a new routine and stake out territory in a new way. Even the legendary Hachiko might have been exhibiting a love for nothing more than a routine, making a daily trip to the train station because, well, that's the way it's always been done.
Yet something rebels at so reductive a view. Animals are not insensate--less sensate than us, certainly, but able to bond and romp and care and suffer in their own particular ways. Our ability to feel, including our ability to grieve, extends far into the emotional ultraviolet--a spectrum that is surely invisible to animals. But suppose they feel only in the visible spectrum--suppose they feel only in black and white? A lesser, blunter, briefer grief is not the same as peace or joy. Grieving profoundly, King argues, is the price humans pay for caring profoundly. It's not too much to suggest that the same equation, albeit on a lesser scale, has to balance for animals too.