Daytime birth and parturition assistant behavior in wild black-and-white snub-nosed monkeys (Rhinopithecus bieti)...

Few quantitative descriptions of parturition behavior have been reported in wild nonhuman primates because the majority of births occur at night. We have recorded a daytime birth event of a primiparous black-and-white snub-nosed monkey (Rhinopithecus bieti). The partum stage lasted 4 min 30 s, and the female skillfully severed the umbilical cord, ingested the placenta, and held and licked the newborn infant. During this period, the laboring female received delivery assistance from a multiparous female in same one-male unit (OMU) and female juveniles from same OMU showed great interesting during the partum. Our case study suggested that there might be considerable individual variation in birth-related behaviors.