The area around Mt. Fuji, which is one of Japan's world cultural heritage, has abundant nature and is a region with high biodiversity. In recent years, as the number of foreign tourists has increased, the number of tourists who enjoy sightseeing by rent-a-car has also increased. In this way, Mt. Fuji and its surrounding areas are the most popular tourist spots in Japan, but the WVC is also an issue for biodiversity conservation and traffic safety. Therefore, in order to conserve wild mammals and ensure traffic safety, the purpose was to clarify the occurrence status of WVCs and their factors.
Around Mt. Fuji, WVCs of mammals, birds, and amphibian reptiles were collected from 2014 to 2018 in collaboration with the Mt. Fuji Outdoor Museum and citizens. In this study, we focused on mammalian WVCs, and analyzed 7 species (sika deer Cervus nippon, raccoon dog Nyctereutes procyonoides, badger Meles meles, hare Lepus brachyurus, squirrel Sciurus lis, Palm civet Paguma larvata, and marten Martes melampus).
The analysis was analyzed by the kernel density estimation method using GIS to clarify the hazard map of the WVCs distribution of wild mammals. In addition, regarding the factors related to the occurrence of WVCs, the road structure along the route (slope face condition, lighting, speed sign, caution sign, number of lanes, median strip, fences, guardrails) was tabulated.
In addition, in order to investigate the traffic volume, which is one of the causes of WVCs, we conducted a traffic volume survey during the daytime (before nightfall) and at night (after nightfall). In the traffic volume survey, we classified motorized motorcycles, passenger cars, medium-duty trucks, heavy-duty trucks, buses (including sightseeing buses), taxis, and rent-s-cars, and counted the number of vehicles per 30 minutes.
The concentration points of WVCs differ depending on each mammal, but many were confirmed on National Routes around the lake. On the other hand, WVCs of most species except masked palm civet were confirmed, although they are few on the Fuji Subaru Line and Fuji Skyline.
Although the number of WVCs is small at Fuji Subaru Line and Fuji Skyline, it is thought that the cause of WVCs is the influence of seasonal changes in the behavioral ecology of wild mammals. The starting point of the Fuji Subaru Line is 857m and the ending point is 2305m, which is an altitude difference of 1448m.
In the analysis of the relationship between the number of vehicles and the number of WVCs, the number of vehicles per 30 minutes reached a plateau at 500, and the number of WVCs decreased thereafter. This means that traffic volume and speed show a positive correlation to a certain extent, but at some point, they reach a plateau and the traffic speed decreases. Therefore, it was shown that the occurrence of roadkill is high in relatively medium traffic volume.
For the factors that cause roadkill, model selection is performed using a statistical model and the relevance is analyzed.