Reactions to infant death by wild vervet monkeys (Chlorocebus pygerythrus) in KwaZulu-Natal, South Africa:\xa0prolonged carrying, non-mother carrying, and partial maternal cannibalism

Jennifer Botting,Erica Van De Waal

doi:10.1007/s10329-020-00851-0

Abstract

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.

Highlights

In recent years, thanatology, the study of death and dying, has received considerable research interest from primatologists (Anderson et al 2010; Anderson 2017; Watson and Matsuzawa 2018; Gonçalves and Carvalho 2019)
To add to this sparse literature on dead infant carrying in vervet monkeys, we report 13 observations of mothers carrying recently deceased infants, and one observation of a sub-adult female carrying her deceased infant sister, recorded in Mawana Game Reserve between 2010 and 2019
Observations were made on seven groups of wild vervet monkeys at the Inkawu Vervet Project, Mawana Game Reserve, KwaZulu-Natal, South Africa (28°00.327S, 031°12.348E) between 2010 and 2019

Summary

Introduction

Thanatology, the study of death and dying, has received considerable research interest from primatologists (Anderson et al 2010; Anderson 2017; Watson and Matsuzawa 2018; Gonçalves and Carvalho 2019). Many authors report primate mothers continuing to direct caretaking behaviours towards their dead infants This usually involves carrying the infant, and sometimes other caretaking behaviours, such as grooming, vocalizing, swatting away flies, and trying to prevent other group members from taking the corpse (Biro et al 2010; Fashing et al 2011). In a recent review, Gonçalves and Carvalho (2019) collated reports of dead infant carrying in 34 primate species (or subspecies). Primates (2020) 61:751–756 includes a photograph of the dead infant being handled, but no further information To add to this sparse literature on dead infant carrying in vervet monkeys, we report 13 observations of mothers carrying recently deceased infants, and one observation of a sub-adult female carrying her deceased infant sister, recorded in Mawana Game Reserve between 2010 and 2019. We used non-invasive observational methods of data collection on animals in their natural habitats, and all individuals were habituated to human observers

Results

Findings

Discussion