*2.2. Trait Data*

We compiled trait datasets for amphibians, reptiles, and mammals in Europe using several available databases (published papers, books, electronic databases; Supplementary Material, Table S1). The selection of traits was based on the completeness of the availability of species' trait data and on their previous use in quantifying amphibian, reptile, and mammal functional diversity [19,29]. Our trait selection process resulted in the following five functional trait categories (with sub-categories): (a) body length (body mass for mammals), (b) clutch size (litter size for mammals and some viviparous amphibians and reptiles), (c) activity time (nocturnal, diurnal, crepuscular only for mammals), (d) diet type (herbivore, insectivore, molluscivore (only for amphibians and reptiles), carnivore, and omnivore), (e) habit (aquatic, fossorial, ground dwelling, and above-ground dwelling/arboreal). Traits a and b were considered as numerical variables, and traits c–e as binary variables.
