Awareness of death in non-human animals (Part 2)

Awareness of death in non-human animals (Part 2)

In this second part we expand the range of animal species that have been shown to exhibit unique behaviors after the death of a relative or companion. In these new cases we will see how both domestic and wild animals react surprisingly to death. More examples which suggest that the human being is not the only living being conscious of death and the only one who can feel pain towards it.

In the previous post we established the four components necessary to understand death that are applied to adult humans: inevitability, irreversibility, non-functionality and causality. Meanwhile, an animal’s response to death involves any behaviour made by an individual after the death of a companion, and scientists distinguish it from grief, where various conditions have to be given. Firstly, two or more animals choose to spend time together. Secondly, after the death of a relative, friend, or companion, the behavior exhibited by the survivor(s) is different from the normal behavior exhibited before the death. The key criteria for this type of behaviour are the significant alterations in social behaviour, diet, sleep and/or expressions of emotional affection and such alterations must persist for hours, days or weeks.

In the first part of this post we described a series of documented cases in various species of non-human primates (chimpanzees, gorillas, macaques…), dolphins and elephants, in which individuals reacted surprisingly to the death of their congeners. Here we expose new cases of behaviour towards death to complete the examples we gave in the previous post. Although it is true that in the first post we only exemplify cases of wild mammals, in this case we will talk about domestic animals and other groups of vertebrates in which certain aspects of these behaviors can be glimpsed.


There are many cases in which our beloved pets have manifested sadness when they have lost a human companion or one of their same species. One example is Greyfriars Bobby. This is how the most famous dog in Edinburgh (Scotland) is known, who remained 14 years at the grave of his owner, John Gray. John was a gardener who emigrated to Edinburgh around 1850 with his family, hoping to improve their life quality. Due to soil damage caused by the long duration of low temperatures, John abandoned his gardening profession and joined the local police force as a night watchman. When the family adopted Bobby years later, it accompanied John through the streets of the city every night while he was working. Unfortunately, John died years later, in 1858, of tuberculosis, but Bobby did not separate from his friend’s grave. The man in charge of the Greyfriars cemetery where John was buried, decided to build a shelter for Bobby, as it did not move away from the tomb despite inclement weather. Even citizens guided and fed it. Bobby frequented the restaurant Greyfriars Place every day (it had gone to this restaurant with its friend John for years) and, after receiving the food, quickly returned to the cemetery. But the citizens’ demonstration of affection for the dog does not end here. In 1867 the mayor of the city, Sir William Chambers, registered the dog and paid his license as it had no recognized owner, declaring Bobby a pet of the City Council, since it was approved a law that forced to register all the dogs of the city due to the great increase of street dogs. Bobby died in 1872, with 16 years, next to the tomb of its friend John. This is the reason why the animal has been known as Greyfriars Bobby. A year after its death a fountain with a statue of the famous dog was built, which has become an important tourist spot. This amazing story is another example of the great loyalty of dogs to their fellow humans. Even films like Greyfriars Bobby (1961) and The Adventures of Greyfriars Bobby (2006) have been made about this story.

Statue of Bobby located in Edinburgh. Scotland Welcomes You

However, Bobby’s fame is overshadowed by the story of another dog that is practically part of the universal culture. Hachiko was the name of an Akita dog who became famous worldwide due to the film Hachi: A Dog’s Tale (2009), starring Richard Gere. Hachiko was born in 1923 and it was the companion dog of Hidesaburo Ueno, a professor of agronomic engineering at the University of Tokyo. Every morning the dog accompanied its owner to the train station, then returned home alone and at sunset it came back to meet his owner. Nevertheless, one day Hidesaburo did not return. On May 21, 1925, the professor died while he was in class. However, Hachiko continued to wait for him at the station every day for 9 years, until it died in 1935, apparently from brain cancer and filariasis (a parasitic disease), as revealed by the necropsies made on its dissected body years later. As with the previous case, this moving relationship touched the citizens, who took care of the dog and fed it every day. Hachiko became known as “the faithful dog” and in his memory, in 1934, they built a statue of the dog at the station where he waited every day. There is also another statue at another train station, near the place where Hachiko was born, and a monolith with the dog’s name was built next to the professor’s grave.

A) Grave of the Professor Ueno and monolith of Hachiko. Wikipedia B) Statue of Hachiko and its owner. La Verdad C)Statue of Hachiko at the station where it was waiting for the professor. La Verdad

Capitán is another pretty famous dog. In this case we travel to Argentina. This dog lived with Miguel Guzmán, its owner, in 2005 in Córdoba. Unfortunately, the following year Miguel died and was buried in the Carlos Paz cemetery, about 35 km from his home in Córdoba. The dog did not witness any of these events so, in theory, it did not know where Miguel’s body was. After that, Capitán left his house and came back several times until one day it never returned. The family thought that it might have been adopted by other people or might even have died, until one day, while visiting Miguel’s grave in Carlos Paz, they found the dog on it. Obviously, they were surprised by how the dog have could found the grave. And this is not trivial, because how the dog could travel 35 km and reach the exact place where its owner was buried remains a real mystery. The citizens who saw it wandering around the cemetery affirmed that at dusk it always slept at its friend’s grave. This happened for 11 years. The family tried to get the dog back with them, but they did not succeed. During the last years of its life, the dog was taken of by Fundación Protectora de Animales (FUPA). Capitán suffered from kidney problems and in February of 2018 died along with the remains of its owner.

Capitán by its owner’s grave, Miguel Guzmán. El Mundo

Another example is Canelo, more famous in Spain and known as “the dog of the people from Cádiz”. In 1990, Canelo’s owner went to the Puerta del Mar Hospital to subjected to dialysis. Unfortunately, the man did not leave the hospital. That day, the dog and its owner said goodbye in the morning as usual. The dog had already accompanied him on other occasions and waited for him at the door of the hospital until the end of the treatment. Surprisingly, after the death of its friend, Canelo waited for him every day for 12 years. An environmental association, Asociación Agaden, adopted Canelo, obtaining the necessary licenses and vaccines so that the animal could continue waiting for its owner without any legal problems. Unfortunately, Canelo was run over in December 2002 while crossing the pedestrian crossing that it had crossed so many times. A pretty gesture took place in May 2004 when the village honoured Canelo and the love it felt for its owner with a plaque with its name and its body in relief in the street where the dog waited for him.

Street dedicated to Canelo. Andalucía información

The next example was told by Isabel Martín and her husband. They had a Shih Tzu dog called Candi. Isabel and her husband worked outside the home, so Candi spent most of its time alone. To avoid this, the marriage adopted a dog male they called Gizmo. Both dogs quickly became inseparable. Sometime later the couple divorced. Isabel kept the dogs, that lived together for 14 years until Gizmo died in June 2012. Since then, Candi did not want to eat or move. The veterinarian diagnosed it with a deep depression due to the loss of its friend. The owner tried hard to make it eat, even forcing it, but the poor Candi resisted a few more months. It died in December of the same year.

Other similar reactions have been described among dogs. This is the case of Joey and Willi, two little dogs who were taken in by the journalist Steven Kotler and his wife in the canine sanctuary they run in northern New Mexico. The two dogs lived with them until their health improved and they were adopted by a friend and neighbor of the family. Tragically, a few days later Joey was run over by a drunk driver. The owner took Joey’s body to the sanctuary because he wanted to bury it there. During the preparations for the burial, Joey’s body was on the bed and Steven’s wife did not separate from it. Willi, the other puppy, climbed up to its side and sniffed its friend’s body. However, the surprise came later, as it grabbed the edge of the quilt between its jaws and covered the face of its dead companion, an act that would not be surprising if a person had done it. At first they thought it was just random, so the woman uncovered Joey’s face. However, Willi became nervous and covered Joey’s head again. But this is not the end of the story. It got late, so they waited until the next morning to bury Joey. Then, when the corpse, which was wrapped in a blanket, was moved to a chair, its head was accidentally discovered. Again, Willi got angry, got on the chair and pulled the blanket to cover its friend’s face. According to Steven, it had never seen such elaborate mourning behavior in a dog in all his years of working with these animals.

Interesting is also the testimony of Jennifer Coates, a veterinarian specialized in care of dying pets. On one occasion, while a co-worker was just about to sacrifice Zoey, one of the dogs of a family, the other two dogs of the family entered the room, stood before the body and began to howl very loudly.

This is just a small sample, but there are many more documented cases and so many others of which there is no public testimony. Let these examples serve as a manifestation of the incredible emotional capacities of our hairy companions.


Although most cats tend to be more independent and sometimes more unfriendly than dogs, this does not mean that they do not have an emotional attachment to their caretakers, owners and fellow cats. Many cases in which cats react sadly to a human loss have been documented, often manifesting anxiety and even depression. Sometimes, for example, they may stop using their sandboxes to do their business or they may stop eating, start being apathetic, meowing loudly and persistently (especially in the dark), etc.

A beautiful and sad story is that of the sisters Willa and Carson. For 14 years, these Siamese cats lived together in the home of Karen and Ron Flowe, in Virginia (USA). The sisters were very close: they played, they groomed each other, they slept intertwined… Carson required several veterinary consultations because it suffered from a chronic illness. When its owners took it to the vet, its sister Willa became very agitated until it returned. However, one day Carson’s chronic disease became worse and it died at the vet. At first Willa acted as usual when its sister was away for a few hours. But after a couple of days, it began to emit strange sounds, like a sort of cry, and went to the places it frequented most with its sister. Months later, the strange behavior disappeared, but Willa remained apathetic.

We can highlight the testimony of veterinarian Jennifer Coates. On one occasion she had to sedate the female dog of a family. To do this, she placed an intravenous catheter to administer the final injection. Until then, the family cat, which was present, remained distant, but when she just began to inject the solution to the dog, the cat lay next to the dog and placed its paw gently on top of its friend’s paw.

We have previously described cases between dogs and humans, cats and humans and between cats and dogs. However, an even more extraordinary case is that between a cat, Muschi, and a female black Asian bear, Mäuschen. Both lived in the Berlin zoo and became inseparable friends. When the bear died, the cat did not want to leave its companion’s enclosure, so it stayed there mewing sadly.

Mäuschen and Muschi. Zoo Berlin


Grief responses in horses have also been documented. When they are going through this situation, these animals may stop eating, feel anxious and spend a lot of time looking for a partner who has passed away.

In an interview with Gemma Pearson, a behavioral veterinarian and member of the Royal College of Veterinary Surgeons (RCVS), she was asked if it was possible for a horse to know if a companion had died. The veterinarian replied as follows:

 “It’s one of those things that we still don’t have enough evidence to say, but in my opinion, they innately understand that something is wrong or something has changed. I think the challenge right now is that it’s not an area that anyone understands enormously. I think you have to give the horses the benefit of the doubt and accept that there will be a sense of loss for them, and try to deal with it as best you can. Be understanding with them and make sure the horse is happy and comfortable in other aspects of his life”.


Marc Bekoff, professor emeritus of ecology and evolutionary biology at the University of Colorado, and co-founder with Jane Goodall of “Ethologues for the Ethical Treatment of Animals,” shared the testimony of a colleague who worked with a group of llamas:

“Llamas are gregarious by nature, extremely perceptive, and forge deep bonds with one another. In the pasture, our llamas often feed in the same area, sleep next to each other, and stay close together when they face off an unfamiliar animal or predator. On the trail, they become extremely agitated if they lose sight of each other when one stops to rest and falls behind. They vocalize quite a bit. My favorite is their delicate greeting call, which sounds like a miniature bagpipe exhaling. When my family moved from Colorado to Alaska, we brought our two Colorado llamas with us. As fate would have it, we inherited two Alaska llamas with our new house and grounds. Each twosome had spent their lives together. At first, the twosomes were a bit standoffish, but in time, they became fast friends and a foursome. Several years later, the oldest llama, Boone, died quite suddenly at twenty-seven years old. One day, he laid down on his side, too weak to get up. The next day, his life partner, Bridger, died in the same fashion, next to him. It was early spring and the ground was still frozen, so we hired a friend with a backhoe to prepare their grave just across the fence. We carefully hoisted Boone and Bridger over the fence and into the ground, then covered them. The other pair, Taffy and Pumpernickel, stood by and watched the entire process quietly. For the next two days, stoic Taffy stood across the fence from the grave and stared at the hole in the ground. She barely moved from the spot. Excitable Pumpernickel stayed in his little barn and wailed for two days. On the third day, they emerged from their grieving and resumed their normal activities. Did Bridger surrender himself to death following the loss of his lifelong buddy Boone? And Taffy and Pumpernickel, both very distinct personalities, grieved in their own personal ways. For me, the most moving memory of losing two llamas so close together was experiencing the caring and harmonious llama death and grieving process”.


Mourning reactions after death have also been described in birds, especially birds that spend their entire lives with a partner, such as geese or songbirds. If a goose loses its lifelong partner, it goes through a mourning process, losing weight and separating from the group. Some even die soon after. If they find a new partner, it is usually another goose who has also lost its partner.

In her book, anthropologist Barbara King also describes an interesting case involving two Mulard ducks (domestic duck crossing between the Peking duck and the Creole duck), Harper and Kohl. These ducks were rescued from a New York foie gras factory and taken to a farm sanctuary. They were in poor physical and emotional condition, they were afraid of people and suffered from liver lipidosis (accumulation of fat in the liver) as a result of forced feeding. In addition, Harper was blind in one eye and Kohl had its legs wounded due to previous badly healed fractures. During their stay in the sanctuary, the ducks became inseparable for years. Unfortunately, one day Kohl began to get worse, so when it could no longer walk, the sanctuary decided to sacrifice it. They did it in front of Harper, believing it would help him. When the event came to an end, Harper at first only pecked its immobile friend, but soon after it lay beside it, putting its head and neck over Kohl’s. It stayed that way for several hours. Harper was never the same after what happened: sometimes it was very nervous around people, never related to another duck… Two months later it died.

Interesting reactions have also been observed in crows (Corvus corax). When a crow dies, other crows summon members of their species, and together they gather around the corpse and squawk loudly. They also often stop eating for a while after a death. However, these kinds of reactions are slightly different from those described above, because they do not seem to feel pain. According to some researchers, crows pay attention to their dead ones and to the place where they die as a way of collecting information about possible threats for their own survival. In other words, the presence of a dead congener in a particular place could inform other birds that that place is dangerous and they have to be careful. The noisy squawking could be a way of alerting the rest of the group.

Magpies (Pica sp.) may not have a reputation as a compassionate animal because of their aggressive behaviour, but a kind of ritual has also been detected in these animals when one of them dies. The above-mentioned Professor Marc Bekoff had several experiences in this regard. He tells how he once saw one of these birds approaching to the corpse of a congener, pecking it softly and retreating from it. Then another magpie did the same thing. After that, one of them flew away, took some grass and placed it next to the corpse. Another magpie acted in the same way. Then the quartet stood still for a few seconds and then flew off one by one. After the professor published what he had experienced, he received several emails from people who had witnessed this kind of rituals in magpies and also in crows.

Another example is the California scrub jay (Aphelocoma californica). Teresa Iglesias, a biologist from University of California-Davis, studied how these birds gather in groups of 2 to 10 around corpses of their species and others. According to the biologist, the calls of these animals attract other California scrub jays and these join the calls or watch in silence from the trees. She has documented that such aggregations can last from a few seconds to 45 minutes. According to Teresa Iglesias, these aggregations may serve to avoid potential risks in the surrounding area.

A) Pica hudsonia, North American magpie. The Cornell Lab of Ornitology B) Aphelocoma californica. The Cornell Lab of Ornitology C) Crow, Corvus corax. The Cornell Lab of Ornitology

Studies do not yet show that these last species of birds (magpies, crows and Californian scrub jays) feel emotional pain towards a dead individual. Even so, the cases that have been documented are interesting and impressive, and suggest that, in one way or another, they may understand death.


French angelfish (Pomacanthus paru). Wikipedia

Infrequent behaviour has also been detected in fish during episodes of deaths of another fish. For example, they often remain immobile in these situations. According to researchers, this could be triggered by the release into the water of a chemical substance called Schreckstoff (known as the shock or alarm substance) by the dying animal. This chemical is released through the skin when there is physical damage, such as that caused by a predator. The compound is detected by the olfactory system of other individuals, so that when other animals detect it they perceive the risk of predation, triggering a behavior of fear and at the same time adopting the appropriate response to avoid predation.

There are not many studies that have investigated whether fish really mourn the loss of their dead. In fact, Franz de Waal, a primatologist and ethologist, said in an interview that he does not believe that mourning is likely in fish, unless they are fish that are closely linked, such as the French angelfish (Pomacanthus paru).

In conclusion…

In the case of humans, it is true that, moreover, we mourn the losses of people we have never met personally and who may live in distant countries or who were once alive in other times, for example, we feel moved when we visit monuments for the fallen or read news about wars or catastrophes. In short, our mourning practices are untethered from time and space.

However, there have been documented cases in which some primates transported the body of their young dead but their daily routines did not change. Would this mean that these mothers did not feel pain? No, these answers simply do not fall within the definition of mourning described at the beginning of the article. What happens is that the expression of mourning, especially in nature, could negatively affect an animal, making it more vulnerable to predation or other forms of death due to any alteration in its routine. So what adaptive sense would this have? Some authors think that perhaps the “social isolation” that accompanies mourning would allow time to rest (if not carried too far) and to recover emotionally, which would lead to greater success in establishing new social relationships. Therefore, more research is needed to refine the definition of grief.

And what about other animals? Some say that the reactions of animals after a death, whether of a human companion or another animal, could simply be attributed to a change in the routine of pets, and that we are who “want to believe” that they are aware and understand death. But we have to be very careful with these statements, because then we would have to analyze all kinds of changes in routines. If a family goes on vacation with their pet and it changes its whole routine, would the animal react the same way such as in death situations? Or something more “negative,” such as a family member who becomes independent after living many years with his/her pet, leaving it in the original home with the rest of the family, how would it behave then? Clearly, it’s not that easy.

Other criticism is that these cases in which people see emotions in animals are due to anthropomorphism (attribution of human qualities or traits to an animal or a thing), a factor that is important to keep in mind during scientific research, as it is a potential bias in determining whether other species understand death. Because, what if non-human animals have other emotional manifestations different from ours that, nevertheless, imply the same thing? What if they have a different concept of death from ours? These are indeed very interesting questions that should be taken into account. Even so, as Professor Marc Bekoff states, emotions evolved in humans and animals because they improve the chances of survival, and:

“it’s bad biology to argue against the existence of animal emotions”.

Allowing surviving animals to spend time in “silence” with the bodies of relatives or companions who have just died is increasingly common practices in sanctuaries, farms, veterinary clinics, zoos, and even private homes. In this way, they are the ones who choose if they wish to express themselves visibly about their loss.

It would be reasonable to think that the species with the highest life expectancy and the species that have the closest relationships with their relatives or group mates, that is, the most social species, are the ones that exhibit mourning behaviors. But the truth is that we still don’t know enough to say this. As Barbara King says, it would be necessary to study and compare the responses to animal deaths in a wide variety of social systems, from gregarious systems to those in which animals gather at specific times to feed or reproduce. Furthermore, it would be necessary to take into account the differences in each type of social context, the personalities of each individual and, of course, the cognitive differences of each species, which make this field even more difficult. What cannot be denied, therefore, is that mourning and love are related, since mourning would appear as a consequence of the loss of love. And what cannot be stated as a result of what has been said in these two articles is that humans are the only ones who are aware of death and the only ones who feel it.

Although the ways in which we mourn may be uniquely human, our capacity for grief has deep evolutionary roots” – Barbara King.



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