Dates of observations on the different species at the basking area of the hibernaculum during spring 2018. The figure represent the period between the first and the last date on which snakes were found there. Black bars represent M. insignitus, grey, P. najadum, white, D. caspius, vertically striped, E. quatuorlineata, horizontally striped, V. ammodytes. The black line presents the mean daily temperature of the microhabitat (Tmh) in days of visitation.