Recordings were made of contact-location vocalizations and behaviors of six troop-living juvenile stumptail macaques. Quantitative analysis of 354 spectrograms distinguished thirteen of the fifteen pairs of animals and led to construction of a "profile" of distinctive acoustic features for the vocalizations of each animal. Individual variation was also found in vocalization occurrence rates in five contextual categories. Acoustic distinctions found between two behavioral contexts were the same found to differentiate similar social settings in Japanese macaques (GREEN, 1975). Individual differences in acoustic features and rates of vocalization are correlated with stages of social development, serve as contextual cues, and are an important source of variability in primate communication. Recordings were made of contact-location vocalizations and behaviors of six troop-living juvenile stumptail macaques. Quantitative analysis of 354 spectrograms distinguished thirteen of the fifteen pairs of animals and led to construction of a "profile" of distinctive acoustic features for the vocalizations of each animal. Individual variation was also found in vocalization occurrence rates in five contextual categories. Acoustic distinctions found between two behavioral contexts were the same found to differentiate similar social settings in Japanese macaques (GREEN, 1975). Individual differences in acoustic features and rates of vocalization are correlated with stages of social development, serve as contextual cues, and are an important source of variability in primate communication.