Altitudinal adaptation of C rotalus intermedius Troschel, 1865 in a natural protected area from Mexico (Squamata: Viperidae)

The geographical distribution of ectothermic animals is determined by the environment temperature, which has effects on physiology and its vagility. Crotalus intermedius is a threatened and endemic species of Mexico with distribution in protected natural areas. The objective of the study was to describe the extension in the geographical distribution of C. intermedius in the Pico de Orizaba National Park (PONP), in Mexico. We use a potential distribution model based on Maximum Entropy that was validated in the field. The results indicate that the highest probability of occurrence of C. intermedius in the PNPO is below 3,600 msnm, but a field occurrence was recorded at 4,080 msnm, which evidences its adaptation to a higher altitude concerning to reported among the known geographic distribution range for the species. In the PONP there has been a gradual increase in the environmental temperature due to climate change, which can promote C. intermedius colonize areas where the temperature is ideal for survival.