Throughout history, man has conceived of himself as the only animal with an awareness of mortality. The philosopher Martin Heidegger came to consider it the most defining notion of the human being, whom he called being-for-death. We tend to think that only we know that death will inevitably come to us, and that the rest of the species live in a kind of eternal present, without any knowledge of the destiny that awaits them. Despite how attractive this idea may be, it is advisable to distrust whenever we hear that this or that characteristic is unique to the human being. We love to tell ourselves stories about how special and different we are from other species, but science in recent decades has been disproving them one by one.
We used to think that ours was the only species that used tools, something that was disproved when, in the 1960s, Jane Goodall observed Gombe chimpanzees using sticks to fish in termite nests. Since then, we have discovered that the use of tools is widespread in nature. Some species of ants, for example, use various wastes (such as pieces of leaves or grains of sand) to transport liquid food to the colony.
We also told each other that human beings were the only animal capable of behaving morally. We now know that empathy and altruistic behaviors are present in many, many other species. Some monkeys, for example, they prefer to go hungry rather than obtain food at the cost of the suffering of a fellow man. Rats will release another trapped rat, even if doing so requires considerable effort or even having to give up some of its food.
In my book Schrödinger’s zarigüeyaAs a result of my post-doctoral research at the Messerli Institute in Vienna, I collect the evidence accumulated in recent years that shows that neither in our relationship with death are we a separate species. Many animals, for example, grieve after the death of a loved one. A couple of years ago, the case of a killer whale named Tahlequah that lost its calf shortly after it was born and was observed around the world carrying the body over 17 days and over 1,000 miles, during which time she barely fed, too preoccupied with not leaving her baby’s body behind. This behavior is very common among primate mothers, who often transport, groom, and protect the carcasses of their young for hours, days, weeks, and even months.
Grief behaviors are also directed toward adult individuals. Recently the case of an adolescent chimpanzee became famous, who when he died caused a great commotion in the group. His companions huddled around the body, inspected and groomed it. Some even attacked him, frustrated at his lack of response. But the most interesting thing was the behavior of an adult female who had had an especially close relationship with the deceased, and which they saw spend several minutes cleaning the teeth of the corpse with a stick.
Another striking case was that of the little gorilla Segasira, who lost his mother at the age of eight, and who they observed sitting next to his corpse, sleeping next to him, sitting on him, hugging him and grooming him. He was also seen trying to suckle on the inert body, despite the fact that it had been weaned for several years, a behavior that was interpreted as an attempt to calm his own distress.
Although our cumulative culture allows us to have elaborate funeral rituals that are absent in other species, we see many behaviors in animals, beyond mourning, that they remind us of several of our cultural tendencies around death. Elephants have been observed depositing vegetation and soil on the corpses of their congeners, an enigmatic behavior that they never direct to living individuals and that resembles a rudimentary burial.
Crows are often seen congregating in groups and circling their deceased, behavior reminiscent of our funerals and that it fulfills the important function of allowing them to learn about the circumstances surrounding the death of the deceased, and thus avoid future dangers. Among great apes it is also common to offer mutual social support in the event of a death. When the chimpanzee Moni lost her baby, the individuals in her group went out of their way to offer her care and affection. One of the apes that increased her affiliation with Moni the most was Tushi, a chimpanzee who did not have a particularly close relationship with her but who in the past he had also lost a baby. Therefore, among animals there are manifestations of empathy in the face of the loss of a loved one, similar to those that occur between us.
They also enjoy killing
Among the animal behaviors in the face of death, we also find some behaviors that remind us of the most embarrassing side of the human being. Our fondness for killing individuals of other species for pleasure or sport is similar to the behavior of killer whales, who they apparently enjoy hunting so much that they often seem to do it simply for fun, attacking other cetaceans to death, and then mutilating them and playing with their remains and then leaving them behind without having eaten.
Also remarkable in this regard is the behavior of dolphins towards porpoises. They have been seen many times harassing these cetaceans and attacking them among various, something that often ends in death. This behavior, however, is not due to predatory motives, since the dolphins never feed on their victims, and they do not appear to be territorial or defense disputes, since the porpoises do not pose a threat to them. Instead, it appears to be a way for dolphins to bond with each other and test their fighting techniques, a behavior that, unfortunately, is not completely alien to our species.
The human being, however, not only kills individuals of other species for pleasure, but is also characterized by annihilating the neighbor when he considers that he does not belong to your group. We are not unique in this either, but it is something very common among, for example, our closest cousins: chimpanzees. These apes are often seen in coalitions of four or five individuals venturing into neighboring territories, in search of solitary chimpanzees from other groups. When they find them, they attack each other until they die.
The discovery of these raids was the definitive demonstration that humans are not the only animals that they deliberately seek out others of their own species to exterminate them. Chimpanzees were also recently observed killing a baby born with albinism within their own group. Although infanticides are common in this species, in this case the behavior seemed to be motivated by the very strange appearance of the calf, something that is reminiscent of some of the most regrettable episodes in human history.
But to what extent do other animals have an awareness of mortality? In my book Schrödinger’s zarigüeya argument that the concept of death is much less complex than we usually think and that it is widespread in nature. The best example to demonstrate this is the one that gives the title to the work. The opossum is a marsupial that, feeling threatened, transforms into a cadaverous version of itself. He is completely still, his vital functions are reduced to a minimum, his tongue turns blue, and he even gives off a putrid-smelling liquid from his anal glands. Contrary to what its compelling disguise might suggest, the possum is aware of its surroundings, ready to return to action as soon as danger passes. Like the cat in Schrödinger’s paradox, the opossum is alive and dead at the same time.
Awareness of death
Despite the elaboration of this defense mechanism, it is an automatic behavior and the opossum probably has as little notion that it is playing dead as a stick insect has that it resembles a stick. However, the very existence of the opossum show shows us that, at the very least, the predators that feed on this species have a concept of death.
This is because, if we do not postulate a concept of death in these predators, it is impossible to explain how the behavior of the possum would have evolved. Like the existence of stick insects shows us that their predators tend to mistake them for sticks (and therefore they have a concept of stick as something that they are not interested in eating), the cadaverous disguise of the possum shows us that predators tend to take it for dead when it is in that state, and therefore that they have a concept of what it means to be dead.
Since the behavior and mind of animals began to be studied systematically in the last century, many of the characteristics that we considered to define us have been falling as we have been finding, at the very least, rudimentary forms of them in other species. The human being is not the only animal that uses tools nor the only one capable of behaving morally. We now know that he is not the only one to kill on purpose and for pleasure, nor the only one to mourn the passing of a loved one, nor the only one to have an understanding of mortality. Although our relationship with death is special in many ways, we also find a lot of continuity in this area. We are not a separate species, like it or not. We are just one more animal.
* Susana Monsó is a Doctor of Philosophy and a professor at UNED. ‘Schrödinger’s possum’ (Ed. Plaza y Valdés), on sale from this Wednesday. Madrid Book Fair (booth 156).
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