Contrasting effects of climate, land use, habitat structure and predation on two Mediterranean lacertids at their range edge

Introduction: Land-use changes have transformed many Mediterranean ecosystems in ways that can adversely affect ectotherms such as reptiles. Range-edge reptile populations may be especially sensitive to such changes, as their thermoregulatory requirements depend on an interaction between climate and habitat structure. Here, we asked how climate, land use, predation risk and habitat structure affect two potentially interacting lacertid species at their southernmost range edge: the Levant Green Lizard Lacerta media israelica and the Lebanon Lizard Phoenicolacerta laevis. Methods: Between 2016 and 2018, we sampled both species in 272 woodland sites spanning a 120 km geo-climatic gradient in northern Israel. We quantified land cover, habitat characteristics and predation pressure by Cattle Egrets (Bubulcus ibis), a known predator of both species. We modelled species abundance to evaluate the effects of climate, land use, habitat structure, egret predation pressure and the potential effect of L. media on P. laevis. Results: We recorded 158 L. media individuals and 1,162 P. laevis individuals in 16.5% and 77.2% of sites, respectively. L. media abundance was positively associated with wetter conditions and heterogeneous habitats and negatively associated with cattle grazing. In contrast, P. laevis abundance was unaffected by climate, increased with vegetation productivity, but had negative associations with L. media abundance and increasing egret predation pressure. Conclusions: L. media and P. laevis exhibited contrasting responses to climate, land-use, habitat structure and biotic interactions. Therefore, closely-related reptile species sharing a range edge can respond differently to abiotic and biotic conditions, suggesting a need to refine biogeographic expectations. Highlights Range-edge lizard species can differ in their responses to climate and habitat conditions. Habitat closure following land-use change can adversely affect some cold-adapted species. Generalist species may be less sensitive to climate conditions at their range-edge. The expansion of Cattle Egrets has adverse effects on lizard populations. The expectation of increased climatic sensitivity of range-edge ectotherms should be refined to account for local adaptation.