Replication Data for: From fecal analysis to satellite data: monitoring large herbivore diets in rewilding efforts

This dataset comprises information on diet quality of free-ranging horses and cattle from the Faia Brava Reserve, as well as vegetation indices for the same area. Diet quality data were collected monthly between July 2021 to May 2022 for both species. Subsequently, using multispecies NIRS models (fecal nitrogen: Villamuelas et al., 2017; fecal fibers: Rossa et al. 2025), we quantified fecal nitrogen, neutral-detergent fiber (NDF), acid-detergent fiber (ADF), and acid-detergent lignin (ADL) contents for each sample. Vegetation data were obtained from satellite imagery acquired by the LANDSAT 8 Operational Land Imager (OLI) sensor, covering a 10-year period from May 2013 to December 2023. This time span was selected to capture the annual vegetation cycle while minimizing the influence of atypical years. The images were sourced from the United States Geological Survey (USGS) via https://earthexplorer.usgs.gov/. We used the Collection 2 Level-2 product (EROS, 2020), which provides multiband imagery at 30-meter spatial resolution and includes surface reflectance data. The spectral bands were used to calculate vegetation indices: the Enhanced Vegetation Index (EVI) and the Normalized Difference Moisture Index (NDMI). Within the Faia Brava Reserve, we delineated 22 polygonal features in Shapefile format using QGIS software (QGIS Development Team, 2023). These polygons represent the dominant habitats of the reserve: grasslands (N = 10), shrublands (N = 7), and Quercus forests (N = 5). For each date with satellite data availability, the dataset reports the median values of EVI and NDMI calculated for each polygon.