抄録
Ecological pressures are principally responsible for species difference in social behavior. Aspects of social organization such as average group size can be adaptive responses to problems of obtaining food or avoiding predation. However, the relationship between ecology and social organization is not very clear. Intergroup competition and species' evolutionary history both affect primate social structure. Individuals' social behavior is a determining factor of variation of intraspecies social structure. Studies of provisioned groups is affected by environmental factors.
