DOI: 10.71758/refodat.73
title: Raw Audio Recordings and BirdNET-Based Bird Species Detections from 22 Temperate Forest Sites in Jena, Thuringia (2024)

description: This data set contains audio files in wave format, recorded between October 2023 and January 2025, from 22 forest sites around Jena, Thuringia, Germany, using AudioMoths, and one .txt file per site containing the BirdNET output after analysing all audio files for that site. These sites form part of the “WZE@Jena” monitoring project (Waldzustandserhebung Jena), which is a long-term survey of forest conditions. This is a joint project between Friedrich Schiller University Jena and Stadtforst Jena. The sites were randomly selected and comprise 20 sites of six different forest types (see below), plus two open-land reference sites. Per site, one AudioMoth version 1.2.0 was installed approximately 2 m above ground on a tree in the centre of the site. They were programmed to record every 15 minutes for 25 seconds at 192 kHz with medium gain. The AudioMoths were installed in October 2023 but were first equipped with rechargeable batteries, of which nearly all failed quickly, resulting in large data gaps in most devices between October and December 2023. In December 2023, the rechargeable batteries were switched to Varta Longlife Power batteries, which performed better in cold weather and, to our knowledge, did not cause additional recording failures. What caused failures, however, were the microSD cards; we used Intenso and Verbatim 64 GB cards, but during the monitoring period (October 2023-January 2025), they failed in large parts, leading to data gaps. For our study we did with this data, we therefore picked four 30-day periods with as much data coverage as possible (winter period: January 1-30, spring period: March 25-April 23, summer period: July 1-30, autumn period: November 1-30, all of 2024) and discarded the rest. Here, we nevertheless provide all recorded audio files. Then BirdNET Analyzer version 2.4 was run on these files using the following specifications: confidence value ≥ 0.1, sensitivity = 1, overlap = 0, and latitude and longitude = 50.92, 11.58 (Jena coordinates). This results in one .txt file per input audio file. Per site, these .txt files were combined into a single .txt file. Note that when in one audio file, no bird species was detected, which results in one row with species name “nocall”. For more detailed descriptions of the methodology see https://git.uni-jena.de/passive.acoustic.monitoring/forest.birds/audiomoths-birdnet. Forest types and sites belonging to them: 256, 418, 544, 709: Woodruff Beech forests: LRT 9130, Galio-odorati Fagetum 225, 253, 284: Oak-Hornbeam forests: LRT 9170, Galio-Carpinetum 696, 697, 758: Calcareous Beech forests: LRT 9150, Carici-Fagetum 415, 446, 581: Hardwood Beech forests: BT 7103-60x, Beech/deciduous mixed forest 200, 641, 650: Pine-Mixed forests: BT 7203-20x, Mixed pine forest 251, 590, 648: Mixed Conifer-Deciduous forests: BT 7403-40x, Mixed deciduous-evergreen forests 196, 286: Open-land reference sites See the “env_variables.csv” as part of the data set “BirdNET-Based Bird Species Detections and Environmental Data from 20 Temperate Forest Sites in Jena, Thuringia (2024)” (also published in Refodat) for environmental variables describing the forest sites. This table does not include data for the two reference sites, as they were not included in the related study. Furthermore, data is not available for most parameters for these two reference sites. Here, however, we provide the coordinates of the two reference sites, along with their altitudes, inclinations, and aspects. Microclimatic data (light, relative humidity, temperature) for these reference sites is available on request: Site 196: Coordinates: 50.919920000, 11.530790000; altitude: 359 m above sea level; inclination and aspect: 0 Site 286: Coordinates: 50.917400400, 11.548880900; altitude: 356 m above sea level; inclination and aspect: 0 This dataset is available upon request only. Please contact the authors. If you are only interested in the results of the BirdNET analyses, see the other data set linked below.