Post-mortem infant-directed behaviours in wild Guinea baboons

The growing field of comparative thanatology aims to shed light on how and why the understanding of death evolved. Observations across different nonhuman primate species have reported care-taking behaviour toward dead infants, but also cannibalism. Various hypotheses have been put forward to explain these behaviours, ranging from responses to infantile cues to an understanding of death. To aid comparative analyses and future tests of these hypotheses, we report behaviours toward dead infants in a wild population of Guinea baboons (Papio papio) living in the Niokolo-Koba National Park, Senegal. During 12 years of field observations (2014-2025), we recorded 64 infant deaths within the first year of life. In 22 of these cases, mothers, but occasionally also other group members, carried, protected, groomed, and dragged dead infants. In 6 cases, cannibalism occurred. None of the mothers expressed any signs of emotional distress in response to infant death. We suggest that no concept of death in Guinea baboons needs to be invoked to explain the observed behaviours. Instead, post-mortem caretaking behaviours can be viewed as the by-product of selection for infant care, which includes not abandoning an infant that might temporarily be unresponsive. The lack of infant responses to maternal behaviour, together with the disintegration of the corpse, may drive a shift from perceiving the infants as an object that elicits caretaking to one that is either abandoned or, in some cases, comes to resemble food, ultimately facilitating cannibalism.