I spent three nights spotlighting around Kiso Valley in Honshu. It was raining, and mammal activity was very low (I didn’t see any carnivores or deer, which is unusual for Japan), but I found some good sites:
1. Akasawa Natural Recreation Forest: the forest seemed strangely devoid of mammals, except for one hare near the visitor center, but the river is a textbook example of Japanese water shrew habitat. Blue trail (1.5 km) provides access to a few bridges that make perfect observation posts; I spent six hours there and saw one water shrew from the bridge at 35.729168N 137.625744E. You need a thermal imager because the shrews seem totally intolerant of light. The river also looks good for giant salamanders, but I didn’t see any.
2. Mount Ontake: there are two roads from the SE side to the summit area; one goes up to 1800 m where you can take a cable car to 2200 m; I didn’t try it because the cable car was closed due to weather. The other road ends at 2200 m. The last few km zigzag up a grassy ski slope where hares were abundant despite heavy rain and strong wind; in better weather there should also be voles there. Near the summit parking lot there’s a network of boardwalks through dwarf conifers and small bogs; I saw more hares there and found an Azumi shrew hiding under a boardwalk at 35.873620N 137.502475E. There were red-backed vole burrows in that area. In good weather you can reportedly hike to alpine meadows where mountain mole, lesser Japanese shrew-mole, and serow are said to be common (ptarmigans as well). When I was driving back down in the morning, the rain stopped for half an hour and I saw a family of wild boars and a herd of macaques; in better weather it’s probably a good idea to spend a night just driving up and down that road as there are many interesting habitats and no nighttime traffic. The road is also excellent for herps.
3. Kakizore Gorge. The trail to and beyond the waterfall passes through rare low-elevation habitat of Shinto shrew. Serows can sometimes be seen on winter weekdays. I was there during the day and didn’t see any mammals.
4. Torii Pass (1210 m) is a popular hike, but you can also get to the top by car (the road is marginally passable for a sedan). 200 m south of the pass the main trail crosses a patch of oldgrowth horse chestnut forest (35.950872N 137.795254E), extremely rare in Japan. This area and two stream crossings along the access road from the south were the only places with lots of mammals: in one night of walking around I saw a bear, a wild boar, a dozen greater and a few lesser Japanese mice, a few Anderson’s red-backed voles, two Japanese white-toothed shrews (one of them caught and killed a vole as I watched it all through the imager), and two Oriental black rats (I wonder if such forests were their preferred habitat before they colonized ricefields and other human-modified habitats; note that contrary to most Western literature, this species is native to Japan as there are Pleistocene fossils from Honshu). Endo’s pipistrelles and dormice live in chestnut hollows, but the latter are pretty much impossible to see well. Watch for tiger keelbacks.