The reproductive bioligy of Pallas coluber Elaphe dione in the Volga river basin

Data about Pallas coluber Elaphe dione pregnant females from Samara, Ulyanovsk, Saratov and Volgograd region and about postponed eggs by them in captivity are submitted. Females from the Middle Volga region attain a sexual maturity at larger sizes than that from located in the south regions. Oviposition in the northern regions occurs later, and its period was more prolonged. It was not possible to make an unambiguous conclusion about the geographical variations of the number of eggs and their size. Correlation dependences between the quantity of eggs in oviposition and their length, between the length and diameter of eggs were negative, but correlation between the quantity of eggs in oviposition and their diameter was positive.