A Historical Review of Studies and Conservation Practices for Terrestrial Mammals in the Central and Southern Ryukyu Archipelago in Japan

We reviewed the history of studies and conservation efforts related to terrestrial mammals in the central and southern Ryukyu Archipelago in Japan, covering six orders, 11 families, 20 species, and six subspecies, with 77% endemic and 62% of species classified as threatened. The most significant feature is that phylogenetically ancient species have survived alongside humans, who have inhabited the islands for approximately 30 000 years. This coexistence is unique to this region and not found in other parts of Japan, making it a globally rare phenomenon. In 2021, four islands in the region were designated as Natural World Heritage Sites, marking a conservation milestone, although challenges remain. Island biodiversity is crucial to global biodiversity because of its high endemism. Island biology provides an essential biogeographical perspective to understand evolution and shape conservation strategies. The region has become a focal point of interest due to its unique biota and distinctive island ecosystems. We concluded that a comprehensive re-evaluation of the islands is essential, focusing on biogeography, ecology, and species interactions. Conservation measures should be tailored to each island by incorporating insights from ethnography, sociology, and economics. It is our responsibility to protect the region's endangered species and the biodiversity for future generations.