Behavior and physiology in young bonnet monkeys

Abstract
We studied behavioral development in 12 mother‐reared social‐group‐living bonnet macaque (M. radiata) monkey infants during the first four months of life. Physiological data was subsequently recorded from a subset of six using implantable biotelemetry. We compared these data to similar data previously collected in the same manner from similar age social group living pigtail macaque (M. nemestrina) infants. Bonnet infants were more active and apart from mother more throughout development. While in physical contact with mother, however, they were more likely to be enclosed if they were bonnets, but only in proximity or passively supported if they were pigtails. Bonnets also had more social contact with other adults. Mean day and night heart rate and body temperature, heart rate and body temperature circadian rhythms, and most nocturnal sleep variables were virtually identical in bonnets and pigtail infants. These findings suggest that developmental differences in social behavior in two closely related species of macaque monkey need not be accompanied by differences in physiological patternig.