DOI: 10.5061/dryad.np5hqbzsk
title: Compiled comparative data and the R code from: "Why do some primate mothers carry their infant's corpse? A cross-species comparative study"

description: Non-human primates respond to the death of a conspecific in diverse ways,
 some of which may present phylogenetic continuity with human
 thanatological responses. Of these responses, infant corpse carrying by
 mothers (ICC) is the most frequently reported. Despite its prevalence,
 quantitative analyses of this behaviour are scarce and inconclusive. We
 compiled a database of 409 published cases across 50 different primate
 species of mothers’ responses to their infants’ deaths and used Bayesian
 phylogenetic regressions with an information-theoretic approach to test
 hypotheses proposed to explain between- and within-species variation in
 ICC. We found that ICC was more likely when the infant’s death was
 non-traumatic (e.g. illness) versus traumatic (e.g. infanticide), and when
 the mother was younger. These results support the death detection
 hypothesis, which proposes that ICC occurs when there are fewer contextual
 or sensory cues indicating death. Such an interpretation suggests that
 primates are able to attain an awareness of death. In addition, when
 carried, infant age affected ICC duration, with longer ICC observed for
 younger infants. This result suggests that ICC is a by-product of strong
 selection on maternal behaviour. The findings are discussed in the context
 of the evolution of emotion, and implications for evolutionary thanatology
 are proposed.
description: We searched the scientific
 literature for cases of primate mothers responding to the corpse of their
 dead infant. Cases were cross-referenced using three published reviews
 [5,7,28]. We included only events in which there was enough opportunity
 for the mother to carry the corpse [5]. Specifically, we recorded a case
 of ‘corpse not carried’ if the mother was in the vicinity of the infant
 when the death occurred and the corpse was not consumed or monopolized by
 other individuals or removed by observers after the death, but the mother
 did not carry it. Additionally, we classified attempted but unsuccessful
 lifting (e.g. [30,31]) as ‘corpse not carried’ to avoid interpretation of
 underlying motivation. Our definition thus does not differentiate between
 mothers who are unable or unwilling to carry their young. For each case,
 we recorded 10 variables where possible: (1) the species; (2) the site
 where the case was reported; (3) whether the corpse was carried or not; if
 carried, (4) the carry duration (in days); the mother’s (5) parity, (6)
 age and (7) rank; (8) the infant’s age; (9) the cause of the death; and
 (10) the living condition (wild, provisioned, laboratory or captive). In
 cases where the exact duration was not known, we used the minimum (where
 &gt; N) or maximum (when &lt;N) confirmed carrying days or the
 mid-point of a stated range. We also included the minimum carry duration
 in cases where the corpse was removed after the mother had carried. We
 classified maternal age in two categories (young versus old) to make them
 consistent across studies. In the few cases in which infant age was not
 reported precisely, we took the mid-point of a range, or N + 1 or N−1 if
 it was reported as &gt;N or &lt;N days, respectively. Infant ages
 were divided by the species weaning age to make them comparable across
 species. We also compiled data on additional variables to test further
 hypotheses. These additional variables included information about the
 species or the site. Specifically, we recorded the: (1) daily travel
 distance for the species at the site; species’ (2) degree of
 terrestriality, (3) body mass and (4) level of maternal investment; and
 the site’s (5) maximum temperature and (6) climate type. See Electronic
 Supplementary Material, §2.1, of this paper (https://doi.org/10.1098/rspb.2021.0590) for details of how these variables were measured and of resources from which they were obtained.
description: The readme file contains a description for each of the variables
 in the thanatobase, their units, and the allowable values. NA =  value not
 available. The readme file also includes a description of other files that
 can be found here and that were used in the analyses. Finally, there is an
 specific readme file for the additional varibles (variables used to
 calculate some variables of the thanatobase).