According to new research, in the Democratic Republic of Congo and Rwanda, there are wild gorillas who exhibit a variety of behaviors around dead members of their species. Behaviors include grooming, sniffing, and poking the dead. One surprising case showed a young gorilla attempting to nurse from his mother which suggests that these primates, like humans, can grieve for the dead. “Humans were once considered unique in having a concept of death but a growing number of observations of animal responses to dying and dead members of their species suggests otherwise,” according to the new study.

Questions Lead To New Research

There have been questions about how an animal’s previous relationship with the deceased connects to how they behave once that individual has passed away. Previous relationships could include anything between differences in sex to the social rank of the deceased. Ants, for example, remove and bury their dead while elephants and primates quietly engage in caretaking behaviors of the recently deceased. Amy Porter and Damien Caillaud, from Atlanta’s Dian Fossey Gorilla Fund International, led a study to document and identify the unique behaviors of mountain gorillas when in the presence of a recently deceased gorilla. They were assisted in the research by researchers from the University of California Davis, Uppsala University, and the Congolese Institute for the Conservation of Nature.  The researchers were primarily interested in how the gorillas would respond according to their different social standings especially since gorillas are known to observe a hierarchy.

Three Gorilla Cases

The new study focused on the responses of mountain gorillas in three different cases and situations. The first involved the death of a 35-year-old dominant male silverback mountain gorilla (Gorilla beringei beringei), named Titus, in Volcanoes National Park in Rwanda. The second case also involved the same species and same location but this one was the death of a 38-year-old dominant female, named Tuck. Both cases involved gorillas who were attended by the members of their social group. The final case was a little different because it involved the corpse of a silverback Grauer’s gorilla (Gorilla b. graueri) who was discovered by a different social group even though they were from the same species. The third gorilla had died in Kahuzi-Biega National Park in the Democratic Republic of Congo (DRC). The researchers documented the gorillas’ behaviors through field observations, photos, and videos. For all three cases, the gorillas had died within hours of the observations. Researchers believed that the two gorillas from Volcanoes National Park had died due to old age.

The study into the reactions to death based on social standing showed some interesting results that the researchers were not expecting. In the first two cases, the researchers expected the gorillas to pay the corpses more attention, but they weren’t sure how the gorillas would react to the unfamiliar, outsider male gorilla. The gorillas typically sat next to the corpse in all three cases, resting near or in contact with the body, and showing odd behaviors toward the body such as licking, sniffing, poking, and grooming. Researchers also observed some more aggressive behavior from the younger gorillas including breast-beating, smashing plants, or even hitting the corpse. The gorillas who had a close relationship with the deceased spent more time around the corpse often spending days sleeping next to them.

One young male even tried to feed on the breast of his mother, Tuck, even though he had been weaned off, showing some signs of distress. Seeing the different ways, the animals reacted to the deaths of their loved ones was heartbreaking but one thing the researchers noticed was that there was a noticeable difference between the two gorillas in the Volcanoes National Park and the out-group gorilla. There was an absence of adult females around the corpse of the out-group Grauer silverback which was fascinating. Porter explained that “the most surprising behavior was definitely how similar the behavioral responses were toward corpses of integral group members and the presumably unknown group member. In gorilla society, interactions between groups or between a group and a lone silverback—a potential competitor—generally results in aggression or avoidance with or without physical contact. In all three cases, almost every member of the group sat quietly around the corpse and many individuals sniffed, licked, and groomed the deceased.”

More Study Is Needed

Porter and her team admitted that it is difficult to determine the emotional lives of gorillas, and it’s tempting to argue that, in the two mountain gorilla cases, the ones who reacted the most were those who had a close relationship with the deceased. Porter stated that “many researchers are quick to discount grief as an explanation for observed behaviors claiming it is speculative. From my perspective, I think we have a lot to learn about the ways animals engage with the world, especially animals like gorillas who are incredibly intelligent, as I am certain they experience emotions that are more complex than we have accounted for.”

New research is needed according to Porter and her team, but Porter believes that future studies “should pay special attention to the frequency with which corpses are encountered and to the circumstances that lead to group members being abandoned before death and those that receive prolonged attendance.” However, these behaviors around the dead could also lead to the spread of dangerous diseases like how human corpses give off strange fumes and chemicals when decomposing. The time spent with the corpses, sometimes with great intimacy, could lead to the spread of transmissible diseases that could cause a decrease in the gorilla population. This possibility needs to be further researched to see what could happen if they continue to grieve the way that they do.