The hatchling snakes measure about twenty centimetres and are the offspring of three adult female snakes. Vipers commonly give birth to 3 to 7 baby snakes, usually in September. However, this year, the warm spring greatly sped up their pregnancy. Even though the common European viper is a relatively common snake, breeding is not simple. “It requires an exact combination of heat, cold and moisture, and young vipers are also very fussy,” Petr Velenský, the zoo’s curator of reptile breeding, explains.


Heat is not good for vipers

Some of the baby snakes born this year will stay in the Zakázanka exhibition, and others will be transported to other zoos where breeding did not work. In the outdoor exposure, vipers can be observed in mild and cloudy weather. In the heat, the snakes seek cover to cool down.

According to Velenský, some new youths will manage to start eating the food delivered to them by themselves, but breeders have to provide artificial and quite complex feeding methods for others. In Zakázanka, where common vipers live outdoors all year round, adult snakes sometimes need nutrition supplements.


Viper or smooth snake?

People often confuse the common European viper with the smooth snake, which also lives in the Czech Republic. The only reliable distinguishing feature is the characteristic continuous zigzag pattern that most vipers have. However, some vipers can be entirely black. On the contrary, smooth snakes sometimes have spots on their backs, which can look like a zigzag stripe when moving, which can confuse the observer.

The viper is generally a small snake, up to about 60 cm, whereas the smooth snake can be longer and is thinner than the viper. If you are still unsure, try looking the snake in the eye. The smooth snake has round pupils, while the viper has a pupil resembling a cat’s, an oblong shape with peaked ends, like a slit in the centre of the eye.

In the Czech Republic, the common viper is protected as a critically endangered species.

For further information, please visit the zoo’s website: