DOI: 10.5061/dryad.kh18932gx
title: Data from: Shedding light with harmonic radar: Unveiling the hidden impacts of streetlights on moth flight behavior

description: One of the most dramatic changes occurring on our planet is the
 ever-increasing extensive use of artificial light at night, which
 drastically altered the environment to which nocturnal animals are
 adapted. Such light pollution has been identified as a driver in the
 dramatic insect decline of the past years. One nocturnal species group
 experiencing marked declines is moths, which play a key role in food webs
 and ecosystem services such as plant pollination. Moths can be easily
 monitored within the illuminated area of a streetlight, where they
 typically exhibit disoriented behavior. Yet, little is known about their
 behavior beyond the illuminated area. Harmonic radar tracking enabled us
 to close this knowledge gap. We found a significant change in flight
 behavior beyond the illuminated area of a streetlight. A detailed analysis
 of the recorded trajectories revealed a barrier effect of streetlights on
 lappet moths whenever the moon was not available as a natural celestial
 cue. Furthermore, streetlights increased the tortuosity of flights for
 both hawk moths and lappet moths. Surprisingly, we had to reject our
 fundamental hypothesis that most individuals would fly towards a
 streetlight. Instead, this was true for only 4% of the tested individuals,
 indicating that the impact of light pollution might be more severe than
 assumed to date. Our results provide the first experimental evidence for
 the fragmentation of landscapes by streetlights and demonstrate that light
 pollution affects the movement patterns of moths beyond what was
 previously assumed, potentially affecting their reproductive success and
 hampering a vital ecosystem service.
description: Description of methods used for collection/generation of
 data: Moth males of different species were released
 individually in the center of six circularly arranged high-pressure sodium
 streetlights (radius: 85 m). A similar number of
 individuals was tested each day with the streetlights either turned on or
 off to compensate for daily fluctuations in weather and ambient light
 conditions. A harmonic radar (Raytheon Marine GmbH,
 Kiel, NSC 2525/7 XU) was used to track the flight paths of individual
 moths. All-sky photometry was used to measure spatially
 resolved sky brightness utilizing a commercial digital single-lens reflex
 camera (Canon EOS 6D) with a full-frame CMOS sensor (20.2 Megapixel)
 operating with a 180° circular fisheye lens (Sigma 8 mm f/3.5 EX
 DG). Methods for processing the data:
 The CR2 images retrieved by all-sky photometry were processed
 with the software “Sky Quality Camera” to get luminance values for each
 pixel. Standards and calibration information: We used a
 calibrated digital all-sky camera.
 Environmental/experimental conditions:
 Experiments were only performed during warm summer nights without
 rain or strong wind.
description: # Data from: Shedding light with harmonic radar: Unveiling the hidden
 impacts of streetlights on moth flight behavior This file was generated on
 2024-09-03 by Jacqueline Degen ## GENERAL INFORMATION Date of data
 collection: from 2018-06-10 until 2018-07-29 Geographic location of data
 collection: 50°48'50.3"N, 8°52'32.7"E ## DATA &
 FILE OVERVIEW Data_Manuscript_Shedding_light_with_harmonic_radar.xlsx:
 Dataset for analysis and figures ### DATA-SPECIFIC INFORMATION FOR:
 Data\_Manuscript\_Shedding\_light\_with\_harmonic\_radar #### Worksheet 1
 - Positions: * XY coordinates of the release site and the six
 streetlights. #### Worksheet 2 - Data: Number of variables: 10 Number of
 cases/rows: 2636 Variable List: * Waypoint: Number of the recorded radar
 signals within each flight. * Flight: Number of the recorded flight. *
 Animal_ID: Identification number of the moth. * Species: Species of the
 moth. * X: X coordinate of the recorded radar signal. * Y: Y coordinate of
 the recorded radar signal. * Lights_ON: Information on whether the six
 streetlights were turned on or off. 1 = on, 0 = off * Flight_NR:
 Information on the number of flights performed by one animal, only one
 moth was tested twice. * Date: Date and time of the recorded radar signal.
 * SQS1-SQS12: Mean luminance (mcd/m²) for sectors 1 - 12. The all-sky
 image taken at the start of each flight was divided into 12 sectors
 spanning 30° each (0° to 30° - 330° to 360°). Luminance values (mcd/m²)
 were calculated using the “Sky Quality Camera” software. Missing data
 codes: NA