Effects of land-cover transformation and climate change on the distribution of two endemic lizards, Crotaphytus antiquus and Sceloporus cyanostictus, of northern Mexico

Two species of lizards, Sceloporus cyanostictus and Crotaphytus antiquus, are restricted to small areas of rocky hills in the center of the Chihuahuan Desert, where land-cover transformation has increased dramatically in recent years and future climatic changes are expected to be severe. The current geographic distribution of each species was estimated by ecological niche modeling using the Maximum Entropy model (MaxEnt). A recent land-use map was used to determine areas where habitat has been transformed by human activities, and niche models were projected under one simulated climatic scenario and for two periods of time (2020 and 2050) to estimate their future potential distributions. Results indicate a high degree of anthropogenic habitat transformation within the distribution of C. antiquus, and a significant reduction of its current distribution is expected by 2050. For S. cyanostictus land-cover transformation is less severe, however a severe reduction of its current distribution is expected in the future because of climate changes. Despite the uncertainty involved, the general trends seem highly feasible and immediate conservation actions are recommended.

► The global warming event is causing highly accelerated climatic changes.
► Lizards cannot evolve rapidly enough to track current climate change.
► Our model indicates a severe reduction in distribution of Crotaphytus antiquus by 2050.
► Our model indicates a significant reduction in distribution of Sceloporus cyanostictus by 2050.
► We consider our results as an “early warning” of a possible outcome.