Motivation: The understanding of physiological adaptations, of evolutionary radiations and of ecological responses to global change urges for global, comprehensive databases of the functional traits of extant organisms. The ability to maintain an adequate water balance is a critical functional property influencing the resilience of animal species to climate variation. In terrestrial or semi-terrestrial organisms, total water loss includes a significant contribution of evaporative water loss (EWL). The analysis of geographic and phylogenetic variation in EWL rates must however account for differences in methods and potential confounding factors which influence standard measures of whole-organism water loss. We compiled the global and standardized SquamEWL database of total, respiratory and cutaneous EWL for 325 species and sub-species of squamate reptiles (793 samples and 2536 estimates) from across the globe. An extensive set of companion data and annotations associated to the EWL measurements of potential value for future investigation, including metabolic rate data, is provided. We present preliminary descriptive statistics for the compiled data, discuss gaps and biases, and identify promising avenues to update, expand and explore this database. Main types of variables contained: standard water loss rates, geographic data, metabolic rates. Spatial location: global. Time period: data were obtained from extant species and were collected between 1945 and 2020. Major taxa: Reptilia, Squamata including lizards, snakes and amphisbaenians. Level of measurements: individual samples of animals from the same species, locality, age class and sex category. Software format: csv. Keywords: ectotherms, functional traits, homeostasis, hydroregulation, macrophysiology, evaporative water loss.

Compilation of the database was funded by the Centre National de la Recherche Scientifique (CNRS), the Agence Nationale de la Recherche (Aquatherm: ANR-17-CE02-0013 to JFLG) and a doctoral grant from Ecole normale supérieure to CC.