Abstract
During surveys in 1989-93, 23-28 groups, or 750-890 monkeys, were confirmed living in the western district of Aichi Prefecture. Until the mid-1950s, no crop-raiding was reported in the area. It was found that the distribution of Japanese macaques gradually expanded along the river systems downward from the deep inside of the higher mountains. Japanese macaques began to appear more often and nearer to crop fields. As years passed by, the damage to crops became more severe. Social changes in agricultural villages, especially mass emigrations and rapid advancement in the age of farming workers within the past forty years, may be closely associated with changes in the distribution and behavior of Japanese macaques. The mechanisms by which recent changes occurred in local populations of Japanese macaques are discussed.
