Mean occupancy estimates for saproxylic beetles and butterflies in Switzerland between 1930 and 2021

This repository contains mean annual occupancy estimates for 595 saproxylic beetle species and 216 buttefly species (Papilionoidea, incl. Zygaenidae moths) in six biogeographic zones in Switzerland. The data cover the years 1930–2021 (occupancy estimates were determined per two-year interval; 1930/31, 1932/33, etc.). Mean occupancy denotes the average number of 5 km x 5 km squares occupied by the focal species in a zone. Occupancy estimates are derived from occupancy-detection models that were based on species record data which is hosted and curated by info fauna (metadata available from GBIF through https://doi.org/10.15468/cjmjy2 and https://doi.org/10.15468/atyl1j). Data on the level of single Markov chain Monte Carlo (MCMC) iterations of model fitting are included (4,000 sampling iterations). The six biogeographic zones were defined based on biogeographic regions and elevation (squares with a mean elevation above 1,400 m asl are summarised in the "HighAlps" zone). The study is part of the INSECT project. A detailed description of the methods is given in the following publication:Neff F, Bollmann K, Chittaro Y, Gossner MM, Herzog F, Korner-Nievergelt F, Litsios G, Martínez-Núñez C, Moretti M, Rey E, Sanchez A, Knop E (2026). Ninety-year trends reveal sharpest insect declines in the mid-twentieth century. Nature Ecology & Evolution. https://doi.org/10.1038/s41559-026-03074-6. The repository contains the following two files: occ_means_1930_sapro.csv: Mean occupancy estimates for the 595 saproxylic beetles species occ_means_1930_butter.csv: Mean occupancy estimates for the 216 butterfly species Both files have the same structure. Each row is contains the estimates for a species in a two-year interval and a biogeographic zone. The files contain the following columns: Name_std: Species name two_A: Two-year interval, named by the first year of the interval (integer) zone: Biogeographic zone with the following levels (categorical): Jura Plateau NorthernAlps CentralAlps SouthernAlps HighAlps n_squares: Number of 5 km x 5 km squares that were included in the models for the respective zone (integer) occ_m_i0001 – occ_m_i4000: Mean occupancy estimates for the MCMC iterations 1–4000 (real number)