2016 Volume 56 Issue 2 Pages 159-165
Raccoon dogs (Nyctereutes procyonoides) may use the same setts originally dug by Japanese badgers (Meles anakuma). When ecological niches of two sympatric species overlap, competitive exclusion is possible. Thus, we expected that these species have altered their appearance timing (period in a year and/or time zone in a day). In this study, three infrared sensor cameras were set up near setts in Ohanna-yama, Ohno, Uenohara, Yamanashi Prefecture that had previously been inhabited by both badgers and raccoon dogs, and their activities were monitored from late June to mid December 2014. Japanese badgers and raccoon dogs showed altered periods and time of appearance near the setts. This finding suggests that the two species used the same setts but at different times. Compared to Japanese badgers, raccoon dogs were spotted more frequently near the setts and the duration and ratio of their exploratory behavior were longer, suggesting that Japanese badgers possibly spent more time inside the setts than did raccoon dogs. These results suggest that raccoon dogs shared the same setts as Japanese badgers, but avoided accidental encounters with them using their exploratory behavior, based on their sense of smell.
