Dead infant carrying by chimpanzee mothers in the Budongo Forest

It has been suggested that non-human primates (hereafter primates) can respond to deceased conspecifics in ways that suggest they experience psychological states not unlike humans, which would indicate they exhibit some notion of death. Here, we report long-term demographic data from two East African chimpanzee groups. During a combined 40-year observation period we recorded 191 births of which around a third died in infancy, mostly within the first year. We documented the post-mortem behaviour of the mothers and found that Budongo chimpanzee mothers routinely carried deceased infants after their death, usually until the body started to decompose after a few days. However, we also observed three cases of extended carrying lasting for more than 2-weeks, one of which was followed by the unusual extended carrying of a substitute object and another which lasted three months. In each case, the corpses mummified. We discuss these data in view of functional hypotheses of dead infant carrying in primates and regarding the potential proximate mechanisms involved in this behaviour. We suggest that chimpanzees may exhibit psychological processes related to death of conspecifics similar to human grieving.

Postverta, Agrippa, Caesarea

The frequency of breech presentation at term is 3% among singletons. Greek physicians dreaded those births, as they frequently led to the death of mother, infant, or both. In Rome, surviving infants were named Agrippa (born with difficulty), and the goddess Postverta was revered for presiding over breech deliveries. To the antique procedures of embryotomy and hook for the dead infant, the Middle Ages added manoeuvres to turn and extract a living, albeit often traumatized infant. These manoeuvres were associated with asphyxia from cord prolapse or compression, fracture of legs, arms, or clavicles, cerebral haemorrhage, trauma to the cerebellum, tentorium, or pituitary stalk, and with torticollis and arm plexus palsy. The prototype of difficult birth, infants born feet-first were considered dangerous, and were neglected or killed in many cultures. Even after Caesarean section had lost most of its risk, conservative obstetricians still propagated vaginal delivery from breech presentation. Finally, at the beginning of the 21st century, large randomized trials and population-based studies proved that Caesarean delivery was safe for the mother and highly beneficial for the child, making vaginal delivery from breech presentation obsolete.

The behaviours of a female blonde capuchin (Sapajus flavius) towards her dead infant

Here we describe the behaviour of a female blonde capuchin (Sapajus flavius) towards her dead infant and discuss possible explanations linked to the anecdotal event. We conducted our study in a fragment of Atlantic forest in Northeastern Brazil where we have been monitoring a blonde capuchin population, with over 163 individuals, since 2010. Our observations show that the behaviours of female blonde capuchins towards dead infant include corpse carrying, which may be related to maternal-bond strength and grief management. Two adult males cooperated with the vulnerable female by protecting her during group travelling even though offspring survival was no longer a possibility. The present study complements the current knowledge of thanatology in Neotropical primates.

Reactions to infant death by wild vervet monkeys (Chlorocebus pygerythrus) in KwaZulu-Natal, South Africa: prolonged carrying, non-mother carrying, and partial maternal cannibalism

Observations of dead infant carrying have been reported for many primate species, and researchers have proposed several hypotheses to explain this behaviour. However, despite being a relatively well-studied species, reports of dead infant carrying in wild vervet monkeys (Chlorocebus pygerythrus) remain scarce. Here we report 14 observations of dead infant carrying by female vervet monkeys in a population at Mawana Game Reserve, KwaZulu-Natal, South Africa. Most of the females carried the dead infant for a day or less, but one female carried her infant for at least 14 days. In one case the maternal sister of a dead infant carried it after the death of their mother. We also report a case of mother-infant cannibalism: a female consumed part of her deceased infant’s tail. Other post-mortem care-taking behaviours such as grooming, smelling and licking were also recorded. Of 97 recorded infant deaths in this study population since 2010, 14.4% are known to have elicited dead infant carrying, a proportion similar to that reported for other monkey species. We discuss our observations in relation to various hypotheses about this behaviour, including the post-parturition hormones hypothesis, learning to mother hypothesis, and unawareness of death hypothesis.

Behaviour of nonhuman primate mothers toward their dead infants: uncovering mechanisms

In comparative thanatology, most reports for nonhuman mammals concern mothers' behavioural responses to their dead offspring: most prominently, dead-infant carrying (sometimes of extended duration); but also inspection, proximity, maternal care such as grooming, protective behaviours and filial cannibalism. Documented across many primate species, these behaviours remain poorly understood in all. The literature is dominated by relatively brief qualitative descriptions of isolated anecdotal cases in apes and monkeys. We argue for quantitative coding in case reports, alongside analyses of longitudinal records of such events to allow objective evaluation of competing theories, and systematic comparisons within and across species and populations. Obtaining necessary datasets depends on raised awareness in researchers of the importance of recording occurrences and knowledge of pertinent data to collect. We review proposed explanatory hypotheses and outline data needed to test each empirically. To determine factors influencing infant-corpse carriage, we suggest analyses of deaths resulting in ‘carry’ versus ‘no carry’. For individual cases, we highlight behavioural variables to code and the need for hormonal samples. We discuss mothers' stress and welfare in relation to infant death, continued transportation and premature removal of the corpse. Elucidating underlying proximate and ultimate causes is important for understanding phylogeny of maternal responses to infant death. This article is part of the theme issue ‘Evolutionary thanatology: impacts of the dead on the living in humans and other animals’.

“A Fine Mixture of Pity and Justice:” The Criminal Justice Response to Infanticide in Ireland, 1922–1949

MH, a domestic cook who was 26 years of age, was charged with murdering her newborn infant in September 1931. MH had been “seeing a boy” who, she stated, “took advantage” of her on one occasion, procuring her consent to sexual intercourse by a promise of marriage. She claimed that she only realized she was pregnant during the later months of her pregnancy, but did not inform the father of her child. Her employer, suspecting that MH was pregnant, enquired on several occasions whether she could do anything to help, but MH did not admit her “condition.” Although her employer was aware that MH had no family or home to go to, she gave MH notice to quit her job. A couple of weeks later, MH gave birth in her bedroom at her employer's home; she did not call out for assistance or disturb the girl with whom she shared the bedroom. MH admitted in her statement that the baby cried after birth and that she “tied a white dress belt … around its neck to kill it,” adding: “I tied it [the belt] tight. I killed the child and I know I killed it.” Afterwards, MH put the body in a suitcase, cleaned up the bloodstains, and returned to work. The suspicions of her employer eventually lead to the discovery of the dead infant. The postmortem examination showed that the infant had been born alive, but had received no attention at birth; death was the result of strangulation. MH was acquitted of murder at the Central Criminal Court.