Striped individuals of the grass snake, Natrix natrix (Linnaeus, 1758) in anthropogenic habitats of Berlin, Germany, might indicate human introduction.

We report three recent observations of striped individuals of the grass snake (Natrix natrix) from Berlin, Germany. Such animals have been described from the region earlier, although this color morph is typical for south-eastern European populations. All three observations were made in anthropogenic habitats, which have been highly frequented by visitors for decades. Based on our anecdotal findings and recent publications on the morpho-geography of the species, we hypothesize that introduced individuals might play a more significant role in the polymorphism of grass snakes than previously thought. Finally, we overview all published observations of striped grass snakes in Central Europe and discuss the implications of potentially introduced non-native genotypes. [ABSTRACT FROM AUTHOR]