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

How a nonhuman primate mother responds to her dead infant is an indication of maternal behavior and perspectives on death. Here we describe three cases of a mother's response toward her dead infant in Yunnan snub-nosed monkeys (Rhinopithecus bieti) at Baimaxueshan Nature Reserve in Yunnan, China. The mother, whose infant died at 1 month of age, showed strong maternal affection to the corpse and carried it for 4 days. A mother with a stillborn infant showed similar maternal behavior to her dead offspring, but only held it for 1 day. The mother of an aborted infant abandoned the carcass without carrying it or displaying other forms of maternal behavior. Our results suggest that the mother-infant bond in the Yunnan snub-nosed monkey is strongly influenced by the infants' age. Postdeath infant-carrying behavior could be affected by the combined action of reproductive hormones and the emotional response of the mother. This manuscript represents the first detailed report of a mother carrying her dead infant in this endangered monkey species.