Application of Maxent Multivariate Analysis to Define Reptile Species Distributions and Changes Related to Climate Change

The maximum entropy Maxent statistical technique was applied to determine the habitat extent of seven reptile species and to objectively delineate distributions and bioclimatic thresholds. For each species, Maxent ranked the relative importance of each of the input bioclimatic concerns and provided charts which were used to define species bioclimatic survival thresholds. It was discovered that the thresholds corresponded with the spatial distribution of the bioclimatic factors almost exactly at those threshold levels through much of the range for each of the species. As a result, it can be shown with a high degree of assurance that the majority of a reptiles range can be delineated with just a few bioclimatic concerns specific to that species and that the northern boundaries of the seven reptiles in this study are all controlled by temperature and the western boundaries are all controlled by the amount of precipitation.