Publications (FIS)

Detection and validation of common noctule bats (Nyctalus noctula) with a pulse radar and acoustic monitoring in the proximity of an onshore wind turbine

authored by
Polina Krapivnitckaia, Jannes Kreutzfeldt, Helge Schritt, Holger Reimers, Carolin Floeter, Michael Reich, Veit Dominik Kunz
Abstract

This paper presents the results of bats detected with marine radar and their validation with acoustic detectors in the vicinity of a wind turbine with a hub height of 120 m. Bat detectors are widely used by researchers, even though the common acoustic detectors can cover only a relatively small volume. In contrast, radar technology can overcome this shortcoming by offering a large detection volume, fully covering the rotor-swept areas of modern wind turbines. Our study focused on the common noctule bats (Nyctalus noctula). The measurement setup consisted of a portable X-band pulse radar with a modified radar antenna, a clutter shielding fence, and an acoustic bat detector installed in the wind turbine's nacelle. The radar's detection range was evaluated using an analytical simulation model. We developed a methodology based on a strict set of criteria for selecting suitable radar data, acoustic data and identified bat tracks. By applying this methodology, the study data was limited to time intervals with an average duration of 48 s, which is equal to approximately 20 radar images. For these time intervals, 323 bat tracks were identified. The most common bat speed was extracted to be between 9 and 10 m/s, matching the values found in the literature. Of the 323 identified bat tracks passed within 80 m of the acoustic detector, 32% had the potential to be associated with bat calls due to their timing, directionality, and distance to the acoustic bat detector. The remaining 68% passed within the studied radar detection volume but out of the detection volume of the acoustic bat detector. A comparison of recorded radar echoes with the expected simulated values indicated that the in-flight radar cross-section of recorded common noctule bats was mostly between 1.0 and 5.0 cm2, which is consistent with the values found in the literature for similar sized wildlife.

Organisation(s)
Institute of Environmental Planning
External Organisation(s)
Hamburg University of Applied Sciences
Büro für Umweltkartierung, Informationsverarbeitung, Naturbewertung (UIN)
Type
Article
Journal
PLOS ONE
Volume
19
No. of pages
26
ISSN
1932-6203
Publication date
12.06.2024
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
General
Sustainable Development Goals
SDG 14 - Life Below Water
Electronic version(s)
https://doi.org/10.1371/journal.pone.0299153 (Access: Open)