Current status on roadkill of rare amphibians in Amami-Oshima Island ―Amami-Oshima Roadkill Research Group―

Abstract

Considering ecological features of target species is needed to carry out effective countermeasures. Assorted threatened amphibians occur in World Natural Heritage Site ʻAmami-Oshima Islandʼ, however current status of amphibian roadkill has been unknown. Therefore, we documented drive census from October 2020 to September 2021 on each route in three areas. Roadkill of ten amphibian species (183 individuals) was recorded. The number of sword-tail newt roadkill was the largest among amphibians, and the roadkill frequently occurred between November and January. The roadkill of Ryukyu kajika frog concentrated during May. The roadkill of Amami tip-nosed frog occurred through a year and did not change drastically by season. Species and the number of roadkill differed among survey routes. Such factors as distribution patterns and population size of each species and traffic volume might affect the differences. Detailed environmental analysis would be needed for the roadkill data of sword-tail newt, although roadkill occurrences might relate to land use and the distance to water bodies.