Sixteen multiparous Barbary macaque females with newborns were studied over a 16 month period within the context of their naturally formed group. Analysis of their social behavior revealed 1) triadic interactions involving focal females, their newborns, and other group members occurred mainly with other females; and 2) mothers with female newborns interacted mainly with females of their own matriline, while mothers with male newborns interacted mainly with nonmatriline females. Observed in two successive birth seasons, this pattern indicates that partners of maternal interactions chose each other according to the sex of the newborn.
Measures of distance from the mother also reflected differences between infants of different sex. At about five months of age, female infants were observed close to their mothers significantly more often than males. This finding follows the pattern of a sex-specific infant socialization process which integrates female infants into the network of their matrilines and male infants into the broader group. This sex-specific integration pattern is interpreted as supporting female philopatry and male dispersal. © 1995 Wiley-Liss, Inc.