General factors that regulate survival among ectotherms at northern latitudes: a study of sand lizard, Lacerta agilis, habitat in southern Sweden

Abstract: Open sand habitats in Sweden has been declining for the past century and this is mirrored by the increasing fragmentation and attenuation of species bound to these habitats. Many threatened species coexist in the same habitats as sand lizards, habitats best described as warm sites with a long continuity. Often with a sand-based substrate and a mosaic landscape of heather Calluna vulgaris, herbs, and patches of grass. Generally, areas with open sand are one of the keys for species bound to these habitats considering many of the species use south-facing sand slopes as nesting sites since it holds a warmer microhabitat that is beneficial for incubation of eggs and thus is essential for the whole lifecycle. This study investigates four current sand lizard (Lacerta agilis) localities in the county of Skåne and compares them to four empty localities in Southern Halland with similar character. The data collected from the study sites were analyzed to see if there were any significant differences between the populated and empty localities and thus could give information if key structures in the habitat are missing. The result from the analysis clearly shows that both the study sites Vapnö and Långenäsudden have the key structures that are essential for the sand lizard and could be considered as suitable habitats for potential new sand lizard populations. Information about both recreational pressure and predator abundance in these study sites would be an essential step in the final evaluation of the adequacy of the habitat as a whole.