Kyoto Univerisity’s Ashiu Research Forest is located in the northeastern part of Kyoto Prefecture. It is one of the most important remaining areas of primary forest in Western Japan. It contains a mosaic of forest types including patches of broadleaf and conifer dominated areas, some containing areas that have not been managed by humans for over a century.

Japan’s bat species are globally important due to 40% of species being endemic, making studying Japanese species vital for protecting its biodiversity. Within Japan, some bat species are understudied, many lacking basic ecological information. Within Ashiu, its ancient forest may be the key to valuable habitat for threatened and rare species due to large amounts of trees suitable for roosting habitats and insect diversity.

Bioacoustics is the study of animal sounds, how sounds are created, transmitted and received. More than 80% of bat species use laryngeal echolocation to navigate and communicate. Bats emit sound from their mouth or nose at high volumes and frequency that are inaudible to humans. The sound bounces off objects and prey items to help the bat locate them. From sonograms of these sounds, we are able to determine behaviours such as commuting, foraging and social activities, as well as determine species by examining call shapes and frequencies.

Acoustic studies are a valuable tool for monitoring bat diversity in a noninvasive way, as well as being able to catalogue species that are difficult to capture during trapping studies. This is the first acoustic study that has been carried out within Ashiu forest focusing on bats. The aim of this study was to elucidate the basic ecology of bats in Ashiu forest, focusing on their usage of different vegetation types. We investigated species diversity and bat activity in different vegetation types throughout the season using acoustic devices. Sites were selected in broadleaf and conifer dominated sites, and the species composition, temporal changes in the habitat use, and the influence of weather on bats' activity were compared between sites. A Wildlife Acoustics SM4BAT recorder was placed at each site which recorded from 30 minutes before sunset until sunrise from May to November 2023. Ten species have been confirmed, five of which were not known to be present in Ashiu from past trapping surveys conducted in 2010. During this presentation, the impacts of forest type and weather on bat diversity and activity will be discussed.