Positional behavior was quantitatively studied in identified free-ranging Japanese macaques (Macaca fuscata). Five male and 11 female adults were observed in a forested mountain habitat. Data were analyzed for proportion of bout distance, number and time of each locomotion and postural type. Japanese macaques are semiterrestrial, and mainly walk and run quadrupedally. This supports the notion that Macaca are generally quadrupeds. Sex differences in positional behavior were found in the preference of substrate and types of positional behavior. Males and females tend to be terrestrial and arboreal, respectively. Males leap more frequently and longer in distance than do females when they are feeding in trees. These sex differences are considered to be related to differences in morphology, food choice, social activity, and the nursing of infants. Frequencies of leaping and the distance covered by leaping in Japanese macaques are more than those of long-tailed macaques which are arboreal quadrupeds. However, Japanese macaques leap shorter distances at a time than do longtailed macaques, which indicates that body size may be related to leaping distance more than the frequency of leaping and the distance covered by leaping. Japanese macaques are not as specialized for terrestrial locomotion as pig-tailed macaques. They use both terrestrial and arboreal supports, and are considered to be semiterrestrial quadrupeds, somewhere between the arboreal long-tailed macaque and the terrestrial pig-tailed macaque.

Using standard methods, we describe the morphometric characteristics of Indian-and Chinese-derived rhesus macaques (Macaca mulatta) reared at the Primate Research Institute of Kyoto University. The most significant morphometric difference found between the two populations was in tail length, which was ca. 45% and 35% of crown-rump length in the Indian-and Chinese-derived rhesuses, respectively. There were no major differences between the two populations in terms of the other parameters of body size/proportion, although the Chinese-derived rhesuses tended to be larger than the Indian-derived rhesuses by 2-5% and there were some differences in the proportions of extremities. This morphometric similarity can be interpreted from either phylogenetic (recent divergence) or adaptive (similarities in habitat) perspectives.

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Skeletal maturation in the chimpanzee hand and wrist (the RUS system; radius, ulna, and short bones) was studied both longitudinally and cross-sectionally. Maturity states were evaluated in each of the 13 bones of the RUS system based on the TW2 method (Tanner and Whitehouse method), and the RUS score was calculated by the summation of scores for these bones. Individual variation was examined by means of residual curves and pseudo-velocity curves of RUS score and anterior trunk length (ATL). Norms of the age change pattern in RUS skeletal maturation and the growth of ATL were determined for each sex, and the relationships among ATL growth and skeletal and reproductive maturation were examined. We found a fairly good relationship between ATL growth and RUS skeletal maturation. Comparison of growth and development between humans and chimpanzees showed that growth characteristics are coupled with each other at puberty in male chimpanzees and in both sexes of humans. Although nutritional condition influenced ATL growth in infancy, it had no effect on the RUS maturational process. Social relationships appeared to influence both ATL growth and RUS maturation. Analyses on relationships between RUS skeletal maturation, ATL growth, and reproductive maturation, showed that RUS skeletal maturation is a good indicator of "physiological age".