Variation in intergroup encounters in two populations of Japanese macaques

摘要: The nature of intergroup encounters differed between two populations wild Japanese macaques (Macaca fuscata): the Yakushima and Kinkazan populations. In population, were more likely to result in displacement one group, agonistic interaction was common, dominance usually distinct. When occurred at Yakushima, larger groups tended dominate smaller ones. Conversely, rarely resulted displacement, rare, unclear. Thus, monkeys appear defend resources actively during encounters, while those did not resources. frequency significantly higher than Kinkazan. had very different group densities traveling speeds, both which directly influence chance encounters. Taking these differences into account, we compared observed with predicted by ideal gas model. frequencies about one-third number expected model, suggests that encounter caused density speed. We discuss this intraspecific variation light economic defendability connection habitat evolutionary significance resource defense behavior.