The common adder (Vipera berus) is recognised by the distinctive uninterrupted black zigzag pattern that runs along the back and starts behind the head, where the pattern takes the shape of the letter X or V. The dorsal line is more pronounced in males, which are usually grayish; while females are typically brownish. There are also individuals that are completely black. The head is oval and gradually transitions into the trunk, its stout body continuing into a short tail. The narrow oval pupil is vertical. The common adder grows up to 70 cm, exceptionally up to 90 cm. It feeds mainly on small mammals, but also preys on birds, lizards and amphibians. The young prey on large insects.
The natural habitat of the common adder is moist and cooler areas. It lives on the edge of wetlands, on mires, forest clearings, extensive meadows and pastures, and on rocky slopes and scree; however it avoids areas where the grass snake lives. Viviparity has enabled the common adder to live high in the mountains and extend far north in Europe.
It is widespread across northern and central Europe and the British Isles. In Slovenia it is most common in the Julian Alps and Kamnik Alps and the Karavanke. It also suits the conditions on the high Karst plateaus; it inhabits the Trnovski Forest, Javornike and Snežnik. In the lowlands it is rare.
The common adder is sometimes also called the viviparous adder, as adult females at the end of August or in early September give birth to up to 15 live young, which are 15 to 20 cm long and immediately capable of independent life. During the mating season, in May, the males compete for females with distinctive ritual battles. The males grip the female by the tail; their bodies coil around each other and with their heads strike at the opponent without biting.
The common adder is a venomous animal! The bite is best avoided by not provoking it or handling it. Moreover, humans derive more benefit from adders than harm, so let us not harm or kill them. In Slovenia it is legally protected and, as a vulnerable species, is listed on the Red List of Threatened Reptiles.
