A glimpse into the foraging and movement behavior of Nyctalus aviator: a complementary study by acoustic recording and GPS tracking

Species of open-space bats that are relatively large, such as bats from the genus Nyctalus, are considered as high-risk species for collisions with wind turbines. However, important information on their behavior and movement ecology, such as the locations and altitudes at which they forage, is still fragmentary, while crucial for their conservation in light of the increasing threat posed by progressing wind turbine construction. We adopted two different methods of microphone array recordings and GPS-tracking capturing data from different spatio-temporal scales in order to gain a complementary understanding of the echolocation and movement ecology of Nyctalus aviator, the largest open-space bat in Japan. Based on microphone-array recordings, we found that echolocation calls during natural foraging are adapted for fast-flight in open space optimal for aerial-hawing. In addition, we attached a GPS tag that can simultaneously monitor feeding buzz occurrence and confirmed that foraging occur..., Microphone-array recordings
Microphone array recordings were conducted on a total of 10 days in August 2020 and 2021: August 4 and 5, 2020, June 26, 27, 30, July 2, 28, 30, August 1 and 2, 2021 (total 1210 min), at Tokiwa Park in Asahikawa city, Hokkaido, Japan (N43°46'28.6\" E142°21'27.1\"), in the proximity of N. aviator roosts within hollows of Ulmus davidiana. The measurement was started around 21:00 in 2020 and around sunset (approximately 19:00) in 2021, and the recordings were made for about 2–3 hours for each day until the batteries ran out.
A Y-shaped microphone array, consisting of four omnidirectional microphones (FG-23329-C05; Knowles Electronics, Itasca, IL), was placed at a height of approximately 1 m above the ground with the microphone tips pointing upwards. Based on the difference in arrival times between a central and three outer microphones, the 3D locations of flying bats were reconstructed using a custom made program in Matlab (Math Works, Natick, MA, USA). The detail..., The [.csv] file is GPS coordinate data generated from the Acoustic-GPS logger, and the [.kml] file shows flight path from this [.csv] and can be opened using Google Earth. One [.xlsx] is the data of sonar emission timing (JST) measured by the acoustic-GPS data logger. The other [.xlsx] file shows all data of sound characteristics of sonar emission of the bats in this study.  The [.csv] and [.xlsx] files can be opened using Microsoft Excel.