Abstract
Although the distribution of Japanese macaques (Macaca fuscata) decreased drastically in size between the late 19th and early 20th century due to an intensification of hunting activities, remnant populations have steadily recovered in recent years. We evaluated the factors influencing recent changes in macaque distribution in eastern Japan by adopting 2 approaches: identifying social and environmental factors that define macaque distribution in terms of expanding areas, non-expanding areas, and areas of extinction from 2002 to 2009 by building a decision tree model; and evaluating the influence of current hunting activities on the recent distribution changes. The present findings were as follows: (1) whereas expanding areas were confirmed in depopulated forest areas at lower elevations, non-expanding areas and areas of extinction were observed in colder mountainous regions and in heavy snowy areas with discontinuous forests, respectively; (2) the tree model indicated that while the classification accuracy for the non-expanding area was quite high at 84.4%, that for the other 2 areas was low at less than 40% because of insufficient classification rules; (3) conventional population control might not have a notable impact on the expanding distribution of recovering macaque populations.
