Mammal fauna detected by camera-trap method around ponds near the alpine forest line in the Northern Japanese Alps

Lakes and ponds in alpine regions are ecologically important elements for not only aquatic organisms but also terrestrial organisms. Nevertheless, there is limited information on how terrestrial animals use ponds and the surrounding vegetation in alpine regions. In this study, we recorded visiting animals using camera traps at three ponds located in the alpine and upper subalpine zones of the southern Northern Japanese Alps for approximately 1 year. Seven mammal species were recorded, including the sika deer (Cervus nippon), Japanese macaque (Macaca fuscata), and Asiatic black bear (Ursus thibetanus). The duration of the snow-free period and the vegetation around the ponds differed between the pond at the bottom of a cirque valley and ponds at the bottom of the linear depressions on main ridges, and differences were also observed in the mammals trapped using the camera around the ponds. The pond on the cirque valley floor, free from snow cover only in the fall season, was used by mammals during this time of year when water resources are most scarce in the alpine region..