MOTHER-INFANT RELATIONSHIPS IN 3 SPECIES OF MACAQUES (MACACA-MULATTA, MACACA-NEMESTRINA, M-ARCTOIDES) .2. THE SOCIAL-ENVIRONMENT

This study compared social interactions between mothers, infants, and other group members in rhesus, pigtail, and stumptail macaques living in large captive social groups. Mother-infant pairs were focally observed in 4 weekly 30-min sessions for the first 12 weeks of infant life. Rhesus and pigtail mothers were remarkably similar in several contact, proximity, and grooming measures, but their scores were lower than those of stumptail mothers. The three species did not differ quantitatively in interest shown in infants by other group members, as measured by infant handling and grooming. Infant handling in stumptail macaques was always gentle and infants were carefully avoided by other group members when off their mothers. Infant handling in rhesus and pigtail macaques also involved harassment and kidnapping. The frequency of infant harassment did not differ in rhesus and pigtail macaques but harassment was more severe in the former than in the latter species. Rhesus mothers reacted aggressively to a higher proportion of infant handling attempts than pigtail and stumptail mothers. These results confirm the hypotheses that female interest in infants does not differ among macaque species and that the quality of infant handling is a good predictor of interspecies differences in maternal protectiveness. Mothering style, however, is probably multidimensionally determined, and to fully understand interspecies differences in mother-infant relationships and their functional significance, we need to understand the mechanisms by which reproductive and ecological variables influence maternal behavior and infant development in primates.