Maternal response to mother–offspring separation in the chimpanzee (Pan troglodytes)
For management and/or research purposes, chimpanzee mothers and their offspring are often physically separated from one another at an earlier age than they would be in the wild. Studies of the behavioural and physiological effects of mother–infant separation on infant behaviour
have been conducted in both human and nonhuman primates. However, few studies have been conducted to examine the response of the mother to separation from her infant, particularly in great apes. The current study opportunistically examined the response of twelve chimpanzee mothers to separation
from 15 of their offspring ranging from 1.8 to 5.4 years of age. Behavioural data (proximity of the mother to other group members, and fifteen behaviours representing six categories [agonistic, prosocial, vocalisations, abnormal, locomotor, inactive]) were collected for three weeks prior to
and three to five weeks following the permanent removal of the offspring from their mothers. A repeated measures MANOVA conducted on all subjects revealed no significant change in behaviour following separation. There was a significant increase in inactivity following separation of the offspring
(F2,21 = 5.47, P < 0.05) in a subgroup of mothers (n = 8) that was studied more intensively on the first day of separation. Maternal age, infant age, presence of other offspring, and past experience with mother–offspring separation had no effect on response to separation.
These results contradict those of mother–infant separation studies in monkeys and indicate that most behavioural indicators of well-being are stable in chimpanzee mothers that remain in their familiar environment and social group following offspring separation.