Data sets and metadata of the paper "Short-term changes in air humidity and water availability weakly constrain thermoregulation in a dry-skinned ectotherm" by Le Galliard et al. Using experiments performed under controlled conditions in climatic chambers, we demonstrate that daytime thermal preferences of a ground-dwelling, actively foraging lizard (Zootoca vivipara) are significantly decreased by restriction in free-standing water availability. Air humidity during the day also influences body temperatures, but its effect is weaker than those of free standing water and depends on the time of day and the sex of the lizard. This confirms that the hydric environment leads to subtle but significant changes in thermoregulatory behaviors in lizards and further suggest that environmental humidity conditions are important methodological factors to consider in the analysis of thermal preferences.

This work was suppported by an Agence Nationale de la Recherche grant (ANR-17-CE02-0013, 'AQUATHERM') to J.-F. Le Galliard. David Rozen-Rechels' PhD grant is funded by the Ministère de l'Enseignement Supérieur et de la Recherche. This work has benefited from technical and human resources provided by the CNRS IR ECOTRONS and CEREEP-Ecotron IleDeFrance (CNRS/ENS UMS 3194) as well as financial support from the Regional Council of Ile-de-France under the DIM Program R2DS bearing the references I-05-098/R and 2011-11017735 and from the European Union FEDER program 2007-2013. It has received a support under the program "Investissements d'Avenir" launched by the French government and implemented by ANR with the reference ANR-11-INBS-0001 AnaEE France.