20 kHz range bat calls recorded on Miyake-jima Island, the Izu Islands, Japan

Abstract

We conducted an acoustic survey of bats from late May to early September 2023 on Miyake-jima Island, the Izu islands. Miyake-jima Island is located approximately 75 km from the Izu Peninsula in mainland Japan. Here, bat calls in 20 kHz range of the FM/QCF shape were recorded in June 2023. These bat calls were made by bat species not previously recorded on the Izu Islands. Based on the shape and peak frequency of the pulse, the calls seem to be those of Nyctalus aviator or Vespertilio sinensis. Further surveys are needed to determine whether the appearance of these bats on Miyake-jima Island was accidental or seasonal.