Whenever animals are seen grieving the dead, we sit up and take notice. In August 2018, an orca calf died off the coast of Vancouver Island, and its mother, Tahelqua, kept its corpse with her for 17 days straight. The images made news around the world. Two years ago, at the Chimfunshi Wildlife Orphange Trust in Zambia, a female chimp named Noel attempted to clean the teeth of her dead adopted son Thomas, dubbed a “mortuary ritual” by many. Elephants are famed for visiting the remains of dead family members, stroking their bones or at times rocking back and forth in what resembles a “vigil”.
每当看到动物在哀悼死去同伴的时候，我们就会聚精会神地认真观察。2018年8月，一只虎鲸幼崽在温哥华岛（Vancouver Island）外海死亡，而它的母亲塔勒托著它的尸体同游了整整17天——这些照片成了全世界的新闻。两年前，赞比亚（Zambia）铜带省野生动物之家（Chimfunshi Wildlife Orphange Trust），一只名叫诺埃尔的雌性黑猩猩试图为她死去的养子托马斯清洁牙齿，被很多人称作“殡葬仪式”。大象们会探望死去的家庭成员的遗体，抚摸或者前后推一推它们的骨头，进行类似于“守夜”的动作。
Can you die from a broken heart?
Most dramatic, in 1972 Jane Goodall witnessed a young male chimp named Flint die just a month after the death of his mother Flo – the male was so despondent following her death that he stopped eating or socializing to the point that he simply didn’t survive.
Whether or not it is possible to “die of a broken” heart, one thing is without question:
“We humans don’t own love or grief – these emotions are widespread in other animals,” says Dr Barbara J King, Emerita Professor of Anthropology at the College of William and Mary, and author of How Animals Grieve.
“并不是只有我们人类才拥有爱或者悲伤——这些情绪也在普遍存在于其他动物之中，”威廉与玛丽学院（College of William and Mary）的荣休教授，《动物如何悲伤》（How Animals Grieve）的作者芭芭拉·金博士（Barbara J King）指出。
Darwin himself thought other animals capable of emotions such as happiness and misery, and stories of elephants mourning the dead were recorded by Pliny the Elder (23-79 AD). Yet for much of the past two centuries scientists and philosophers were extremely hesitant to describe the behaviour of any animal towards one of their dead as “grieving”, for fear of anthropomorphizing – to attribute human traits, emotions, or intentions to animals.
达尔文认为其他动物也具有幸福和痛苦的情感能力，而大象悼念死者的故事被老普林尼（Pliny the Elder，古罗马作家，公元23-79年）记录了下来。然而，在过去两个世纪的大部分时间里，科学家和哲学家都极其犹豫，不愿将任何动物对死去同伴的行为描述为“悲伤”，因为他们害怕将人类的特征、情感或意图赋予动物。
Over the course of her research, Dr King began to feel “that we were straight-jacketed intellectually by our fears of anthropomorphism”, so she created a set of criteria:
“If a surviving animal who had a close relationship to the newly deceased becomes socially withdrawn, failing to eat and sleep and travel in routine ways, and shows species-specific evidence of emotion – then we can see widespread evidence of an emotional response to death in animals.”
The increase in scientific evidence for grief and mourning in other species has grown so much over the past decade, the journal Philosophical Transactions of the Royal B devoted an entire issue to responses to death in both animals and humans, with the proposal to define an entire new field of study: “evolutionary thanatology”.
在过去的10年里，其他物种的悲伤和哀悼的科学证据越来越多，《英国皇家学会哲学会刊》（Philosophical Transactions of the Royal Society B: Biological Sciences）专门发表了一整期关于动物和人类对死亡的反应的文章，提议界定一个全新的研究领域：“进化死亡学”。
The ultimate goal: not simply cataloguing the range of behaviours across the animal kingdom and human cultures, but “developing a more explicit evolutionary consideration of all aspect of studies of death and dying”.
After all, if it is said “nothing in biology makes sense except in the light of evolution” then the question begs to be asked: Why should grief exist at all?
When mourning, both animals and humans behave in a variety of ways that are simply not useful to survival: withdrawing into solitude, retreating from socialising, sleeping less, eating less, foraging less, mating less, and if spending time tending to a corpse, exposing oneself to pathogens and making oneself vulnerable to predators. Taken to the next level in human cultures, with the amount of land we devote to cemeteries, the time and money we devote to funerals, and the profound pain we experience with loss, grief is even more draining – and puzzling.
What can be gained from grieving?
Certain experiences in life may be painful, but that doesn’t necessarily make them maladaptive. When we experience physical pain from a cut or a burn, that pain is an evolved response signaling to us to remove ourselves from the source of pain. Pain is useful. People born with a congenital insensitivity to pain tend to die young, accruing incessant injuries and infections. Pain is useful. But what can be gained from grieving – from retreating from the world, neglecting sleeping and eating?
In this light, understanding when, why, and how animals respond to the dead doesn’t just teach us about animal sentience, or our own evolution – it helps us understand the phenomenon of grief itself.
Because mourning is not limited to big-brained cetaceans (whales and dolphins) or primates – scientists have documented some form of “death response” in seals, manatees, dingoes, horses, dogs, housecats, and more. Striking examples include 27 adult giraffes holding a vigil for one dead baby giraffe, elephants from five different families visiting the bones of one of the dead, a group of 15 dolphins slowing their speed to escort a mother dolphin carrying her dead calf, and a strange case of two ducks rescued from a foie gras farm who formed a friendship at their sanctuary home. When one duck died, the other lay with its head on the others neck for hours.
Though charismatic mammals make headlines, responses to death can also be seen in non-mammals – such as birds, like the foie gras ducks, and wild scrub jays observed in the field.
“We wanted to move beyond anecdotes, and do an experimental study to try and drive at the adaptive value of showing an interest in dead conspecifics,” says Dr Kaeli Swift, who tested how crows would respond to dead crows, pigeons and squirrels left in their environment, publishing her results in that same issue of Philosophical Transactions of the Royal Society B. Crows were more likely to alarm call and recruit other birds in response to dead crows than pigeons or squirrels or stuffed crows mounted in a life-like pose – consistent with the idea that crows exhibit a “danger response” to dead crows.
斯威夫特博士（Dr Kaeli Swift）说：“我们希望超越轶事，做一项实验研究，了解对死亡同类表现出兴趣的对生命的适应性价值。”她测试了乌鸦对留在它们周围环境中的死乌鸦、鸽子和松鼠的反应，并在同一期《英国皇家学会哲学会刊》上发表了她的研究结果。相比于鸽子、松鼠，乌鸦面对死乌鸦更有可能发出警报，并吸引其他鸟类。这与乌鸦对死乌鸦表现出“危险反应”的观点是一致的。
Do humans and animals grieve in the same way?
“There is value in paying attention to your dead to teach you about ways you might die yourself – so you avoid these things,” explains Dr Swift. “There is value in understanding how this behaviour originated in order to understand our own evolution, how this behaviour went from its original state to the enormous suite it manifests in our own species.”
From this viewpoint, understanding the reasons for mourning in animals will help us understand mourning in ourselves. Our responses to death share much in common with animals. For one, like humans, animals will vary in the degree they respond to death – both individually and as species. In general, the more social the species, the more likely they will behave in a manner that could be described as grieving. And the closer two individuals, the more likely one will grieve.
Dolphins and whales for example are both highly intelligent and highly social, so it should come as no surprise that they will attend to a dead member of the pod – most frequently, a mother to a dead calf. This can involve not just dragging or carrying a dead corpse, as in the case of Tahelqua the orca, but also more spontaneous and active behaviours, such as lifting and sinking a corpse up to the surface (as if to help it breathe), and hauling, spinning, and diving with it.
Dr Joan Gonzalvo of the Ionian Project, funded by the Tethys Research Institute, has seen bottlenose dolphins attending to a dead calf on three occasions – twice, with a mother carrying her calf for several days, and once an entire pod struggling to keep a dying baby afloat, then remaining in the area for a time after it died and sank.
忒提斯研究所（Tethys Research Institute）资助的爱奥尼亚项目的琼·冈萨尔博士（Joan Gonzalvo）已经看到过宽吻海豚三次照顾一只死去的小海豚——两次是母亲抱着她的小海豚几天，一次是整个海豚群努力让一个垂死的小海豚保持漂浮状态，然后在它死亡沉没后在该海域逗留一段时间。
“Grieving is a question of coming to terms with the idea of loss,” he says. “So my hypothesis is that when the mothers carried their calves for several days, it was because the calves were newborn, so the death was unexpected and sudden. The mothers needed more time to grieve. But when the pod had to care for an animal that had been struggling for some time already, in some ways it was a relief when it died, so they could move away that day rather than carrying the body for a week.”
As strange as it might seem, carrying the dead body of an infant is extremely common among primates. Many primate species have been observed to carry dead infants for weeks or even months – in extreme instances, mothers have carried their babies until they were completely mummified by the heat, or even just a skeleton or spine remained.
But this is just one of the few ways primates might respond to death: they may exhibit physical interactions with a corpse such as grooming, teeth cleaning and gentle touching, or even rougher behaviours such as hair-pulling, attempted mounting and even cannibalism.
“I have witnessed immensely gentle and careful caretaking, but male chimps can be aggressive in other instances – they are still themselves,” says Dr King, who has observed chimps, bonobos, gorillas and other primates for many years. “Like with people, it’s a mix depending on the personality, and it tends to break down along friendship lines.”
It is the social dimensions in chimps that interest Dr Edwin van Leeuwen of the Max Planck Institute for Psycholinguistics. When he documented Noel cleaning the teeth of her adopted son Thomas – a highly unusual behaviour not seen before – he felt the motivations could be explains through social dynamics.
心理语言学家马克斯普朗克研究所（Max Planck Institute）的莱文博士（Dr Edwin van Leeuwen）对黑猩猩的社会纬度感兴趣。当他记录诺埃尔为养子托马斯刷牙时——这是一种前所未见的极不寻常的行为——他认为可以通过社会动态来解释这种行为的动机。
“I think she was expressing her social bond by doing something with his body,” he says. “Death is one of the most severe social events that can happen in a social species. When a more mature individual dies for example, there needs to be some reforming of social bonds. Or there may be a response by an entire group to a mother that has lost her infant, as a form of social cohesion. In mammalian species – like ourselves – where sociality is of high importance for survival, you see a strong emotional capacity for responding to death.”
For Dr Dora Biro of the University of Oxford, who has observed chimps responding to the dead twice, the implications run even deeper than that.
牛津大学的多拉·比罗（Dr Dora Biro）博士观察到黑猩猩对死者有两次反应，对他来说，这种影响甚至更深远。
“From a developmental point of view, children take quite a long time to acquire a fully complete concept of death. It’s not something that comes naturally to us – it is something we acquire through experiences,” she says.
There are essentially four components to death that psychologists have identified: Irreversibility, non-functionality (the dead do not respond to anything), causality (the biological basis of death), and universality: all living things will die, including yourself.
“When, and in what order did we acquire these components?” she asks. “To understand the extent to which non-humans possess any of these components can tell us a great deal about the evolutionary origins of our own cognition.”
If grief is something we see in highly social animals, and most often seen in individuals with close social bonds, this ultimately tells us a great deal about how mourning is an evolved response to “coming to terms with the idea of loss” as Dr Gonzalvo puts it. Intelligent animals and humans need time to process it. Or, in layman’s terms: grief is the price we pay for love. Little wonder archaeological sites show signs we painted the dead with ochre over 100,000 years ago, and cultures worldwide have developed an astounding array of complex rituals, from funerary rites to cemeteries, decorated coffins to pyramids and even the strange rite of the Torajans who will live with the mummified corpse of a family member for weeks.
There is one further reason we should study grief in other animals, says Dr King.
“This doesn’t just raise the issue of animal welfare – it also points to animal rights,” she says. “If we understand the profound depths of emotions animals can feel, this should make us question the existence of zoos and slaughterhouses around the world, and rethink those systems. Because at present there is a tremendous solace in understanding that the grief we ourselves feel is shared by all kinds of animals worldwide.”