The actual condition of train collisions with large mammals in North Tohoku region

Recently, the number of collisions between large mammals and trains has increased in Japan. It is therefore important to identify factors that might influence the likelihood of collisions and to develop possible remedial measures. Here, we have analyzed data on collisions involving trains and three species of large mammal, namely, Sika deer, Japanese serow and Asian black bear, in the North Tohoku region. These data were collected by the administrators of the East Japan Railway Morioka between 1999 and 2003. Approximately 90% of the accidents involved serow (about 40～70%) and deer (about 30～50%); collisions with bears accounted for less than 10% of the accidents. Collisions with deer peaked in June and October, those with serow showed a single peak in July, and those with bears increased from early summer to September and then decreased. The number of collisions appeared to correlate with population distributions and densities of the various species. Many of the collisions occurred just before sunrise and after sunset. From the results of our analyses, it is clear that effective measures to prevent accidents are required at daybreak and in the evening from May to November.