Data on the distribution and body sizes of two size morphs in the arctic-alpine beetle Amara alpina (Paykull, 1790)doi:10.60507/FK2/GZO1ZZbonndata2026-04-271Beckers, Niklas; Hein, Nils; Vanselow, Kim André; Löffler, Jörg, 2026, "Data on the distribution and body sizes of two size morphs in the arctic-alpine beetle Amara alpina (Paykull, 1790)", https://doi.org/10.60507/FK2/GZO1ZZ, bonndata, V1Data on the distribution and body sizes of two size morphs in the arctic-alpine beetle Amara alpina (Paykull, 1790)doi:10.60507/FK2/GZO1ZZBeckers, NiklasHein, NilsVanselow, Kim AndréLöffler, JörgbonndataBeckers, NiklasBeckers, Niklas2026-04-17Earth and Environmental SciencesWe studied how the distribution of body sizes in A. alpina across Northern Europe relates to the environment. Our aim was to confirm the existence of these two distinct phenotypes of the species and identify environmental drivers to explain their distribution. Our hypothesis was that the differentiation of the species is driven by patterns of snowmelt. We tested this by using a machine learning approach to model body sizes against environmental variables of a dataset with 1x1 km spatial and daily average temporal resolution. The data provided here are the measurements of Amara alpina pronotum width with accompanying information on environemtal variables. Climate data are publicly available from www.senorge.no under the respective coordinates given for each specimen.1985-08-082010-09-28<a href="http://creativecommons.org/licenses/by/4.0">CC BY 4.0</a>Aalp_sizes.txttext/plainreadme_beckers-et-al.txtReadme to interpret datasettext/plain