Amazing stuff!
"In 2018, a female orca named Tahlequah made headlines when she carried the body of her deceased newborn for 17 days, refusing to let it sink beneath the waves. Seven years later, the bereaved mother was seen carrying another dead calf in what seemed to all the world like a display of maternal grief.
Many animals appear to mourn their dead, and some—like elephants and crows—are even known to congregate around the corpses of fallen companions. This morbid behavior comes with multiple risks and costs, making it somewhat baffling from an evolutionary perspective. Carrying a body for prolonged periods of time, for example, can lead to stress and exhaustion: Scientists who followed Tahlequah noted that her “labored breathing and falling behind her pod suggest that she was struggling to keep her calf with her .”
Staying in close proximity to corpses can also expose an animal to disease and heighten their risk of predation. Researchers have observed primate mothers carrying their dead offspring while being attacked by carnivorous wasps, and elephants have been seen approaching corpses in the presence of lions and hyenas.
Staying in close proximity to corpses can also expose an animal to disease and heighten their risk of predation. Researchers have observed primate mothers carrying their dead offspring while being attacked by carnivorous wasps, and elephants have been seen approaching corpses in the presence of lions and hyenas.
These tangible dangers, however, might be balanced by more subtle benefits. ... scientists argue that, by gathering around their dead, animals create hubs of information “where crucial knowledge about the environment and predators can spread among individuals and groups.” The authors dub this theoretical framework “the funeral hypothesis.”
The process begins when an individual dies, triggering a wide range of emotions and unusual behaviors—such as distinctive vocalizations, lack of eating, and staying close to the body—among other animals. These “conspicuous and costly” responses ... cause other individuals to gather around the body, either out of curiosity or a desire to comfort the bereaved.
The sights and smells of a corpse can reveal the cause of death, providing animals with valuable details about predators and other threats in the environment and potentially contributing to a shared “landscape of fear.”
The sights and smells of a corpse can reveal the cause of death, providing animals with valuable details about predators and other threats in the environment and potentially contributing to a shared “landscape of fear.”
These congregations, like human funerals, also serve as an opportunity to strengthen—and sometimes renegotiate—social bonds.
When a matriarch elephant dies, for example, her closest associates spend the most time with her corpse.
In gorillas, time spent around a corpse can be used to assert dominance in the hierarchy.
And although chacma baboons that experienced the loss of an individual they were especially close to showed increased stress levels for months, those that coped by forming bonds with other group members appeared to recover faster.
When a matriarch elephant dies, for example, her closest associates spend the most time with her corpse.
In gorillas, time spent around a corpse can be used to assert dominance in the hierarchy.
And although chacma baboons that experienced the loss of an individual they were especially close to showed increased stress levels for months, those that coped by forming bonds with other group members appeared to recover faster.
The researchers conclude that the funeral hypothesis “helps resolve the paradox of morbidity,” in which behaviors that appear costly ultimately prove beneficial for individuals, groups, “and over time species, thereby strengthening the connections between comparative thanatology and evolutionary biology.”"
From the abstract:
"Numerous species investigate and alter their behaviour around the corpses of conspecifics. However, morbid behaviour creates multiple risks including exposure to disease, predation, and elevated stress levels. Although some causes for morbid behaviour have been postulated, it is not clear if there are adaptive benefits for this reasonably common behaviour that occurs across species. Growing support for information centre theory suggests that conspecifics around a corpse may benefit from shared information.
We hypothesise that corpses are repositories for information and that congregations around them are information centres where crucial knowledge about the environment and predators can spread among individuals and groups. We call this the funeral hypothesis.
The death of an individual may trigger a myriad of emotions (e.g., fear, anger, and sadness) and behaviours (e.g., congregating, not eating, and aggression) in conspecifics. Because these responses are conspicuous and costly, we interpret them as honest signals prompting other individuals, groups, and sometimes heterospecifics, to gather around the signallers and obtain information about the cause of death via visible and olfactory cues such as wounds or grievous injuries, absence or presence of predators, age of the deceased, and decomposition.
This information is then transmitted across multiple levels of complex societies from the individual to different groups. The costs of interacting with corpses are balanced by consolation of bereaved or stressed individuals, enhancing social bonds, facilitating the renegotiation of social positions, and gaining knowledge of threats in the environment. We provide a review linking these concepts and suggest hypotheses generated by the framework."
Corpses as Repositories of Information and Funerals as Information Centres: Why Natural Selection Favours the Bereaved (open access)
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