Fecal pellets of Japanese serow (Capricornis crispus) within the Touki-hodou Tunnel adjacent to Kurobe Gorge Railway in eastern Toyama Prefecture, central Japan

This report describes the occurrence of Japanese serow fecal pellets in Touki-hodou Tunnel (an artificial pedestrian tunnel adjacent to the Kurobe Gorge Railway; 1 m wide and 1.8–2.1 m high) in eastern Toyama prefecture, central Japan. The occurrences of fecal pellets at five locations within the tunnel were described. DNA examination was conducted for five fecal pellets to confirm the identification of species. Serow feces were dotted along both sides in the tunnel at each location at approximately 1 km intervals. Serow fecal matter extended 10–30 cm and comprised >100–200 fusiform-shaped pellets, which adhered to each other. During the late spring to late fall period of 2019, Japanese serow reached 50–370 m deep into the tunnel from the gateways and traveled at least 100–740 m within the tunnel. The Touki-hodou Tunnel could be classified as an artificial cave. As there are no completely dark areas within the tunnel, Japanese serows were able to travel long distances of several hundred meters. At present, it remains unclear what induced Japanese serow to enter the tunnel.