Modelagem de distribuição geográfica para Hydromedusa maximiliani (Mikan, 1820) (Testudines, Chelidae), Brasil

Abstract

The Maximilian’s snake-necked-turtle, Hydromedusa maximiliani, is specie endemic to the Atlantic Forest and endangered in category Vulnerable by IUCN, whose populations are mainly associated with streams inside the forest, but the geographical distribution related to these environments hydrologically dynamic is poorly understood. Species Distribution Modeling has been a tool widely used in recent years. The Maximum Entropy algorithm, Maxent predicts the potential geographic distribution of species from presence data. This study aimed to build ecological models to predict the potential distribution of H. maximiliani that may provide support for development of new strategies for the conservation and thus contribute to the advancement in knowledge about the pattern of their distribution in regions with the Atlantic Forest domain. The occurrence data were obtained between September 2012 and September 2013, through visits to the zoological collections, bibliographic and collection of geographic coordinates in the field. To construct the model we used the Maxent algorithm, aided by ArcGIS version 10 and the digital elevation model of the "Shuttle Radar Topographic Mission". The environmental variables were obtained by Worldclim version 1.1 Cimate Global Surface 10. The model was endorsed by the AUC (Area Under the ROC Curve) and the statistical test Jackknife. 42 points were compiled for the distribution of H. maximiliani. The potential distribution extended from southern Bahia to São Paulo. The generated model showed high predictive ability, with higher AUC value to 0.97, and showed a satisfactory transferability (i.e. ability to predict distributions in regions not sampled ). The high AUC value shows a good distribution model geographic potential of species. However, in models of large scale, this value can be presented proportional to the size of the scale, which would lead to a misinterpretation of the model. However, the areas provided for the distribution of H. maximiliani in this study are realistic and consistent with the distribution realityof the species.