This archive contains pre-processed datasets used for the analysis of species occupancy models, the results of which were used in the calculation of multi-species indices as part of the regional WWF Living Planet Index for Belgium. The datasets are csv files (comma separated and . as decimal mark). For each species group (moths, butterflies and grasshoppers), the following files are available: a species list (files with 'species' in the name) an observations list (files with 'observations' in the name - for butterfly or moth species with two distinct flight periods, also a file with the data for the second generation is available) For one species, Fabriciana adippe , separate files are available with corrected data. The species list files contain the following variables: species_id (unique species id) scientific_name (accepted scientific name according to the GBIF taxonomic backbone) species_name_NL (Dutch species name) species_name_FR (French species name) season_start (n-th day of the year that marks the ...