Evaluation of winter diet composition of Japanese macaques in Kurobe Gorge by fecal analysis: a preliminary report

Abstract

We analyzed fecal contents of wild Japanese macaques (Macaca fuscata) inhabiting Kurobe Gorge, mountain region of central Japan, by the point-frame method. We then compared the macaques’ winter diets with other study sites. Between 2011 and 2020, we collected macaque feces at three areas, a cave, a tunnel, and along mountain trails on steep slopes. The diet of the macaques in fall contained fruits, while in winter it was dominated by bark and winter buds. Compared to other study sites, the percentage of barks and winter buds in feces collected in winter in Kurobe was much higher. Our study supports previous assertions that bark and winter buds are fallback foods in snowy regions, where food availability on the ground is lower due to deep snow.