Abstract Tree cavities are key microhabitats that provide essential resources for cavity-nesting species. Although some studies on cavity-nesting rats have been conducted in temperate and tropical regions, there are no studies in the subtropical zone, especially on islands. The Ryukyu Long-furred Rat (Diplothrix legata, Muridae) is a cavity-nesting rat endemic to the subtropical Central Ryukyus, Japan. This study aimed to describe the interannual and seasonal changes in tree cavity usage and tree cavity selectivity of D. legata. A camera trap survey was conducted to record D. legata from July 2019 to February 2025. Diplothrix legata did not re-nest in the tree cavities used as nesting sites in the following year, and their tree cavity usage was high during December and January, while it was low from June to August. Tree-cavity use increased during the mating and breeding season as juveniles dispersed, whereas it decreased in summer. Furthermore, this species nested in tree cavities located at higher positions in thick trees, because this rat species might select structurally stable and safe tree cavities to avoid predators. On Okinawajima Island, the island’s unique predator fauna may have influenced tree cavity usage patterns and cavity selection of this species.
Higashi et al. (Wed,) studied this question.