Potential distribution and habitat connectivity of Crotalus triseriatus in Central Mexico

Abstract

The dusky rattlesnake, Crotalus triseriatus, used to be very abundant in many parts of the highlands of central Mexico, but with the increasing human population and associated activities, the rattlesnake habitats and populations have suffered drastic reductions and fragmentation. At the moment, the most important habitat features, associated with the presence of C. triseriatus, the current potential distribution and the landscape connectivity amongst the populations of the State of Mexico and Mexico City, are unknown. Therefore, we used the maximum entropy modelling software (MAXENT) to analyse the current potential distribution and most important habitat features, associated with the presence of the species. The variables with the highest contribution to the model were: proportion of Abies forest, minimum temperature of coldest month, maximum temperature of the warmest month, proportion of Pinus forest and annual precipitation. Furthermore, we found connectivity corridors only within mountain chains. Our results highlight the necessity for conserving the patches of Abies forest and preserving the populations of C. triseriatus and the connectivity of the landscape.