The Inhabitation Status of Wild Boars on the Island 10 years after Migration

Abstract

：In this study, we clarified the situation of the wild boar population and damage on Futagami Island, Matsuyama City, Ehime Prefecture, 10 years after the wild boars migrated to the island. First, the REST model was used to estimate the population density, which was estimated to be 69.3 wild boars/km 2 (median value) as of December 2020. The area of possible habitat was estimated to be 1.97 km 2 (86％ of the entire island) , and the number of animals inhabiting the island during the same period was estimated to be 117.8 animals, which is equivalent to 1.4 times the human population. Under such habitat conditions, wild boars easily invaded peopleʼs houses and farmland, damaging warehouses and causing wild boars to give birth near farmland and agricultural facilities. Capturing wild boars is essential for the safety and security of peopleʼs lives, but we also found that the average annual number of wild boars captured on Futagami Island is only 12-34％ of the estimated population. While it is necessary to increase the number of animals captured, it is extremely difficult to recruit new trappers on Futagami Island, which is currently suffering from depopulation and an aging population. Therefore, it is necessary to increase the number of animals captured by expanding public support from outside the island.