抄録
Most studies about mental abilities in nonhuman primates have been held in laboratory conditions. Considering the highy developed social organization of the primate species, however, it is necessary to study about their mental abilities in free-ranging conditions. Numerous studies have been made on natural vocal communication of nonhuman primates. Results of the studies tell mental abilities of nonhuman primates as well as functional significance of vocalizations in their lfe. This paper reviews some studies about nonhuman primate vocal communication and shows examples of mental abilities emerged in these studies, which is recognition of other individuals, perception of quantity, understanding of causal reasoning, categorization, and ability of deception.
