Species Range Mapping from GBIF Using Ecoregion Constraints // Provides a workflow to retrieve, filter, and analyze 'GBIF' occurrence records and to generate ecologically informed species range maps using downloaded or custom ecoregions. The package includes tools for querying the 'GBIF' backbone taxonomy with get_status(), counting or downloading occurrences with get_gbif_count() and get_gbif(), creating custom ecoregion layers with make_ecoreg(), building range maps with get_range(), and evaluating them against independent validation data with evaluate_range() and cv_range(). A disk-based batch workflow (split_gbif_by_species(), species_csvs_to_ranges(), read_range_rds()) supports large multi-species 'GBIF' exports without loading the full table into memory. Bundled ecoregion layers cover terrestrial (Olson et al. 2001 doi:10.1641/0006-3568(2001)051[0933:TEOTWA]2.0.CO;2), marine (Spalding et al. 2007 doi:10.1641/B570707), and freshwater (Abell et al. 2008 doi:10.1641/B580507) realms. The 'GBIF' API is accessed via the 'rgbif' package, and coordinate cleaning uses 'CoordinateCleaner' (Zizka et al. 2019 doi:10.1111/2041-210X.13152). The 'GBIF' API is described at https://www.gbif.org/developer/summary.