Diet and helminthofauna of the snakes Natrix natrix and N. tessellata (Colubridae) co-inhabiting the Middle Volga region

Peculiarities of diet and helminthofauna of grass snake (N. natrix) and diced snake (N. tessellata) in stations populated by the both species have been studied. Diet of the both species includes amphibian and fishes. The former species feed, mainly, on amphibian and the latter one on fishes. Overlapping and interspecific difference of food spectra of the ringed snakes are confirmed by the helminthological data.