Dataset of Raw Post-Construction Bats and Nocturnal Migratory Birds Mortality Monitoring Data from Wind Energy Facilities in France: Before-After-Control-Impact (BACI) Design

Systematic carcass searches around wind turbines within a defined area (a square or a circle with a diameter equal to twice the blade length, with a minimum of 100 m). 2. A minimum of 20 field visits regularly spaced between mid-May and the end of October. 3. Two mandatory experimental bias-correction trials: (a) *Searcher efficiency trials* using randomly placed lures to estimate observer detection rates, and (b) *Carcass persistence trials* to monitor carcass removal rates by scavengers over time.

A limited number of monitoring years prior to 2018 were included to extend temporal coverage. Although these surveys preceded the 2018 revised protocol, they were verified to contain all necessary raw field parameters (complete carcass searches, persistence, and efficiency trial data) required to apply identical bias-correction and estimation methods, ensuring full consistency across the entire dataset. ## Data Processing: - Cleaning: Non-nocturnal migratory bird mortality data were removed of baci_mortality to focus the dataset exclusively on bat and nocturnal migratory bird mortality. - Pseudonymization: To protect industrial confidentiality, wind farm names and exact geographic locations were pseudonymized and replaced with unique numeric identifiers (`park_id`). - Formatting: Data were cleaned, filtered, and aggregated by year, period (Before vs. After period), and curtailment measures (Control vs. Treatment to fit the required BACI statistical design. ####################################### ### DATA AND FILES OVERVIEW ###### ####################################### ## List of variables/column headers: Please refer to the separate metadata file accompanying each individual CSV dataset. ## Missing value code: Missing values are explicitly represented by the standard R code: `NA` (Not Available).