Ottoman viper’s geographic range. A. The currently known global distribution of M. xanthina, shown in red, according to Böhme et al. (2009), Stümpel et al. (2016), and Mebert et al. (2024); B. The approximate previously known distribution range of the Ottoman viper (Montivipera xanthina) in Greece, shown in red (based on Mebert et al. 2024); the newly documented population in the Drama Prefecture, indicated by a green dot; and intermediate localities of unpublished records and photographic evidence of the species, provided by G. Kreiner (pers. comm.), indicated by blue dots. Potential ecological corridors facilitating the species’ dispersal are illustrated in orange, based on generalised habitat suitability and elevation. Maps created using QGIS v3.22.9 “Białowieża” (2022).