After life
Do animals grieve? Are their feelings similar to those experienced by humans? Scientists are dead set on finding out
“A“After the death of the female, which took place early in the morning, the remaining one made many attempts to rouse her, and when he found this to be impossible his rage and grief were painful to witness.”
In 1879, naturalist Arthur Brown recorded this observation after the death of one of a pair of closely bonded chimpanzees at the Philadelphia Zoological Garden. In the actions of the surviving male – hair tearing, plaintive cries and repeated efforts to revive his companion – Brown recognised an intensity of sorrow akin to that exhibited by humans after the loss of a loved one.
This is just one anecdote that appears to demonstrate capacity for grief in nonhumans. But could such displays be the same as humans experience, or is there a lessemotional explanation?
Awareness of death and the emotions of grief were once thought to be defining human traits, but like so many other ‘uniquely human’ attributes, such as tool use, culture and language, this too might be overturned.
For centuries, animals have been observed expressing apparent sorrow at the passing of a group-mate. Many have been our closest cousins, the monkeys and apes, but grief-like behaviours have also been reported in whales, elephants and even magpies. Such reports have often been dismissed as anecdotal anthropomorphism, but the growing field of comparative thanatology – the study of the cognitive, psychological and physiological aspects of death – has of late paid them closer attention. Accumulating reports of intense reactions to death are giving scientists pause for thought: might animals grieve, too?
Beneath the surface
What is grief and what does it look like? This may seem an obvious question, but the more you consider it, the knottier it becomes. Grief consists of outward behaviours, some subtle, others overt, but it is also made up of complex emotions, knowledge and concepts. Without being able to peer into the minds of animals, could we ever truly know whether their outward behaviours correspond to human-like feelings?
For example, one might argue that the ability to grieve as humans do must be predicated by awareness of one’s mortality and that of others. In other words, to know that an individual is indeed dead.
For Professor Barbara King, author of
How Animals Grieve, who believes animals are capable of profound sadness, grief and love, there is little to be gained from this line of questioning. “My research is predicated on observing visible behaviours and understanding the surrounding context, because we can’t read animals’ minds or understand their inner thoughts. What would we have to observe to be able to know about awareness of mortality?”
It might be impossible to know whether an animal can muse on their own mortality, but we can ask, how do animals detect death?
One animal that treats the dead differently to the living is the humble ant. Stories of ants’ treatment of the dead go back thousands of years. Pliny the Elder (AD 23–79) described them as “the only creatures besides man to bury their dead”.
Naturalist E O Wilson further described this behaviour in 1971, explaining how Pogonomyrmex barbatus ants leave worker corpses to decompose in the open air for a few days before they are carefully investigated, then unceremoniously carried away and discarded onto a refuse pile.
Thus, it seems ants can detect death. This is enabled not by fellow-feeling however, but strong scent cues. A pheromone called oleic acid is emitted by dead ants, and it is this that their kin are attending to. Indeed, ants that are alive and well are escorted to the dump if daubed in this scent.
“In this case, the ant’s behaviour is triggered by one cue alone – odour. It will mechanically perform this undertaking behaviour even if there is a live ant presenting this odour, ignoring all other life cues,” explains comparative thanatologist André Gonçalves. “It’s fair to say the ant has no abstract concept of death.”
While nobody is suggesting that ants feel sorrow for their lost brethren, or that this behaviour is motivated by anything other than sanitary concerns, it does suggest how, on a basic level, animals can discern the living from the dead.
Common senses
The entire family of a deceased elephant surrounded her corpse, touching her with their trunks, as if trying to lift her.
At the other end of the scale, humans have evolved to use all five senses when gathering information. “There is a constellation of cues that, taken together, inform us if an individual is dead, from lack of movement, heartbeat and breathing, to grievous injuries, low temperature and odour,” explains André. “Having learned these through experience, humans acquire an internal representation of death separate from the one-dimensional sensory information used by animals such as ants.”
A similar constellation of cues is likely to be how many other animals start to distinguish the living from the dead. They know that a companion normally moves, breathes and is warm, as well as their smell. When an animal detects this change from animacy to inanimacy, how do they react?
From crows, to elephants, to monkeys, animals have been observed to exhibit a range of curious behaviours in response to death. Birds of the Corvidae family, which includes crows and magpies, have been recorded gathering around the corpses of deceased
flock-mates in a way that has been likened to human funerals. One magpie was observed gently prodding at a fallen companion, before gathering some grass and laying it beside its body, as a human might lay a wreath.
Elephants also gather around the bodies of their dead. In one report, the entire family of a deceased matriarch surrounded her corpse, gently touching her with their trunks, as if trying to lift her, while making sounds of apparent distress. The herd eventually fell silent and proceeded to cover her in leaves and branches, before standing vigil by her body for two days.
Not letting go
Studies of whales and dolphins are a particularly rich source of responses to death, and often involve interactions between mothers and their dead calves. In 2018, an orca known as Tahlequah lost her calf shortly after birth. She carried it on her rostrum for 17 days, for more than 1,600km. Tahlequah’s apparent show of grief attracted international attention and was compared to a mourning human mother.
Her vigil, though long, was far from unique in the animal kingdom. In fact, carrying dead infants is one of the most prevalent of all death related animal behaviours. Most prolific at this are nonhuman primates. Monkeys and apes of several species continue to carry infants after death for extended periods, from hours to months. Chimpanzees have been known to take this to extraordinary lengths. In 1992,
a two-year-old wild chimpanzee died of a respiratory illness in Guinea. His mother carried his body slung across her back for at least 27 days, demonstrating extraordinary care even as it rapidly decomposed – grooming it and holding it close to her. By the end of this period, he had become completely mummified and almost unrecognisable.
From these examples, you might conclude animals grieve as we do. Why else would a chimpanzee shoulder the burden of an inanimate infant if not because of a deep emotional bond that it couldn’t bear to break?
We should, however, be wary of ascribing human thoughts and feelings to animal behaviours. Just because a behaviour looks similar to that of a human, it doesn’t mean
Sociality may explain why grief-like behaviours are seen in some species and not in others.
its function or motivation is the same. Some scientists think there may be less-emotional explanations for these reactions to death. One of these goes back to how animals discern the living from the dead, known as the animacy detection malfunction hypothesis.
“According to this hypothesis, such behaviours are brought about by a perceptual mismatch that causes a violation of expectation,” explains André. “The corpse has both animate and inanimate attributes, and this causes a conflict between two separate systems of knowledge in the brain, one for dealing with agents [living beings]; another for objects.”
Put simply, because a dead companion still looks like an animate agent but no longer acts like one, animals become confused. They have not accurately detected death and are still treating the individual as if it were alive. This could explain why primates groom and even sexually mount corpses, and why a mother might carry her dead baby for so long.
In evolutionary terms, it could be advantageous for a mother to not abandon her infant until 100 per cent sure it is dead. Animals don’t have the sophisticated medical means we do to confirm death with accuracy, and it wouldn’t do to abandon an infant who could be in a deep sleep. This rule of thumb could have evolved to ensure infant survival, and a seemingly maladaptive behaviour becomes a generally sensible one.
This hypothesis explains some curious reactions to death. It does not, however, explain all. What about the vigils of magpies and elephants? By assembling around and investigating corpses, group members could be gathering information about how the animal died and assessing a potentially dangerous situation. Animals often learn by experience, forming associations between two events or stimuli. Corvids often avoid the place in which a corpse was found, suggesting that they have come to associate it with danger. This behaviour would have obvious evolutionary advantages.
Animals may also be taking stock of the social changes in the group. All the species mentioned here live in social groups, where the relationships between individuals often hold great importance. Elephants live in matriarchal societies, for instance, while chimpanzees and some corvids live in groups with strict dominance hierarchies, meaning certain individuals claim access to a greater share of food, mates, and other desirable resources. A death, especially of a higherranking individual, can throw these pecking orders into disarray. It may be of paramount importance for group-living animals to keep track of their social structure, to avoid aggravating the wrong individual. Knowing who has died becomes very important.
Sociality may also explain why grief-like behaviours are seen in some species and not others. Numerous animals exhibit responses to bodies in some form, from disposal (ants) to active avoidance (rodents), but the most compelling have been seen in animals with complex social lives. These animals also show striking similarity in their responses.
Interpreting behaviour
However, the existence of these shared behavioural patterns can be explained by both unemotional and emotional reasoning. You could say that social species exhibit complex responses to death because they need to keep track of their social group and avoid dangerous situations, or alternatively, because they form strong emotional bonds that are severed by death and mourned. It may be impossible to know which explanation is more accurate.
And so, we return to the original question – do humans own grief? Ultimately, this depends on how you define it. If we are asking do animals exhibit typical behavioural changes in response to a death, then based on the evidence, we can say yes. But if we are asking if animals feel sorrow akin to ours, we may never know.