We reported one case of parturition behavior and five other cases of maternal behaviors which were rarely observed in a free-ranging group of Japanese monkeys (Macaca fuscata). An eight-year-old female spent more than 3 hours alone before delivery and almost 2 hours afterwards, without being approached by any other group members. The frequency and duration of constractions gradually increased, and the female frequently touched her vulva and perineal region with the fingers of her hand, as the time for delivery grew near. She started to approach other group members about 2 hours after the delivery.
A nine-year-old female did not hold her first newborn to her ventrum after parturition, but walked bipedally, grasping the newborn with both hands. These inappropriate maternal behaviors disappeared the following day. An 11-year-old female carried her newborn ventrally and her yearling dorsally at the same time. This simultaneous carrying of two offspring was recorded for only the first five days after the birth of the newborn. Two other females allowed their one-year-old offspring to nurse after their newborn infant died within two weeks of the infant's life. Moreover, a 13-year-old multiparous female with a four-week-old newborn adopted a week-old newborn and took care of both in the same manner.