An overview of roadkill records on Japanese municipalities revealed by a questionnaire survey

Abstract

 Collecting and accumulating records of wildlife-vehicle collisions are useful for two purposes: to improve road safety, and to monitor the density of wildlife. Such records in Japan are obtained largely from roadkill collected by road managers or cleaners from local or national governments; however, little is known about the records within municipalities. The objective of this study was to provide an overview of roadkill records within municipalities in Japan. Particularly, this study aimed to reveal: the proportion of municipalities that have records of roadkill; the bureau that is mainly responsible for these records within municipalities; how the records are used by municipalities; and what information is usually available in these records. A questionnaire was sent to 650 municipalities across Japan, and was returned by 503 (77.4%) of the municipalities. Of the municipalities that answered the questionnaire, 68.6% recorded roadkill incidents in some way. The answers showed that in the majority of municipalities, cleaners within the municipality recorded roadkill, and road managers did not. About 90% of the records were discarded after 5 years had passed since they were recorded. The municipalities sometimes used the records for accounts of removing roadkill, or to reply to inquiries from citizens or prefectural offices, but rarely used them for preventing wildlife-vehicle collisions. Of the municipalities that answered the questionnaire, 50.1% collected roadkill not only from the municipal roads, but also from the prefectural or national roads, which municipalities have no responsibility to manage. The person removing the roadkill was usually the one to identify what species it belonged to. Each municipality recorded roadkill differently, as either a hand written note or as an electronic file in Microsoft Excel. The information available about roadkill in the majority of municipalities were month, location, and the species or taxa of animal removed. However, only 39.4% of the municipalities recorded all three characteristics. Based on these results, we suggest there should be a standardized system to collect roadkill records in Japanese municipalities, which could be used to improve road safety and monitor the density of local wildlife.