Using maximum entropy to predict the distribution of a critically endangered reptile species ( Eryx jaculus , Reptilia: Boidae) at its Northern range limit

The sand boa (Eryx jaculus) is one of the least known and rarest reptile species in Europe. InRomania, the sand boa is the rarest reptile species with only four locality records being known; atCernavodă, Cărpiniş-Giuvegea, Cochirleni and Mahmudia (Kirițescu 1903; Fuhn & Vancea 1961; Zinke &Hielscher 1990). To estimate the predictors and the probability distribution of the target species (Eryxjaculus) we used MaxEnt 3.3. The potential distribution model of E. jaculus in Romania have a very goodscore performance (AUC = 0.959). The most important variables for the model are BIO13 (92.5% ofcontribution), BIO9 (3.2% of contribution), BIO17 (3% of contribution) and BIO6 (1.3% of contribution).A previously mentioned hypothesis regarding the extinction of the sand boa from Romania hold theconstruction of the Danube River – Black Sea canal as the main responsable factor, this constructionhaving destroyed most of the natural habitats in which the species has been recorded (Krecsak & Iftime2006). We also support this hypothesis as the generated model indicates a suitable niche for the speciesalong the current canal area.