Carrying of dead infants by Japanese macaque (Macaca fuscata) mothers

Abstract

The quantitative and demographic features of infant-corpse-carrying behavior in Japanese macaques (Macaca fuscata) at Takasakiyama, southern Japan, have been studied over 24 years. More than 91% of the dead infants that were carried by their mothers were abandoned within a week. Mothers of all age classes exhibited this behavior and neither the carrying rate (number of carriers/number of deaths) nor the duration were significantly different between young and older mothers. The sex of the infant was not a decisive factor. Nearly 80% of all cases observed involved infants that had died within 30 days of birth. The oldest infant whose corpse was observed being carried had died at 253 days. The overall carrying rate was 15% when death had occurred within 253 days and 28.7% for infants that died within 30 days of birth. Most mothers whose infants had lived for more than a month abandoned the corpse soon after death. Some females persist in exhibiting behaviors performed towards live infants but the exact reasons for this are unclear at present.

Maternal responses to dead infants in Yunnan snub-nosed monkey (Rhinopithecus bieti) in the Baimaxueshan Nature Reserve, Yunnan, China

“…The aborted infant was never carried, the stillborn infant was only carried for only 1 day, and the infant who died at 1 month of age was carried for 4 days. A similar pattern has been reported in squirrel monkeys (Saimiri sciureus) (Kaplan 1973) and Japanese monkeys (Sugiyama et al 2009) and may be related to endocrine changes during pregnancy and postpartum that provide a basis for the formation of a strong mother-infant attachment bond (Maestripieri and Zehr 1998;Bardi et al 2001). Physiological-endocrinological changes during the first few days of postpartum may act in coordination with the cognitive-experiential system in helping primate mothers to attach with their infant (Bardi et al 2004).…”

“…Recently, several papers have been published detailing maternal and individual responses in primates to the death of group members. In primate species such as Japanese macaques (Macaca fuscata), gelada baboons (Theropithecus gelada), and chimpanzees (Pan troglodytes), mothers have been observed to carry the bodies of their dead offspring for several days (Sugiyama et al 2009;Cronin et al 2011;Fashing et al 2011). In other species such as mountain gorillas (Gorilla beringei), group members are reported to exhibit allomaternal behavior toward another's dead infant (Warren and Williamson 2004).…”

Owners’ Perceptions of Their Animal’s Behavioural Response to the Loss of an Animal Companion

“…Dolphins also show great interest in deceased individuals [31]. Japanese macaques have been documented to carry their deceased infants for up to a week before abandoning them [86]. Chimpanzees have been reported to carry their deceased infants for up to two months [87] before abandonment, and Cronin et al [88] have described a behavioural response, including carrying and touching, of a chimpanzee mother towards her dead infant.…”

Twinning frequency of Japanese Macaques (Macaca fuscata) at Takasakiyama

“…Although the sample size is small, twin infant survivorship to 1 month was 72.2%, which is significantly lower than that of the whole infant population of Takasakiyama (data from 9 years, 1987-1993and 2003-2004, Sugiyama et al 2009) (Fisher's exact test, two-tailed, p \ 0.001). On the other hand, twin survivorship to 12 months was 66.7%, which is lower but not significantly different from the whole infant population (p = 0.247).…”

“…Not all but many macaques could be individually identified by facial features and other characteristics and sometimes by artificial markings, such as tattoos or hair dye (Sugiyama et al 2009). The Takasakiyama Natural Zoo has been working everyday from 8:30 to 18:00 throughout a year, and all births were recorded by five or six staff of the Feeding Ground Section.…”