Common Viper

snake and is known for being remarkably resistent to low temperatures. It is also the most widespread species of snake in the world and is found from the British Isles in the west, to the Chinese coast in the east. The snake itself is quite small, adult females rarely grow beyond 70 centimeters and males rarely over 60, although most crossed vipers encountered are much smaller. Their food consists mainly of rodents, amphibians and lizards, although birds and their eggs are sometimes consumed. The name of the viper comes from the black crossed pattern on its back.

The Crossed Viper is venomous and the lethality of its venom is equal to that of rattlesnakes', but because it injects much smaller amounts of the venom, the animal is considered less dangerous. A bite from a crossed viper is only rarely lethal and even then it is usually due to an anaphylactic reaction. In fact, bees are considered more dangerous to humans and only small children, allergic adults and seniors in poor health are at risk. Nevertheless, if bitten by a crossed viper, one should immediatelly but calmly seek medical assistance.

The adult female crossed viper is often rusty brown, with the black pattern on its back and grows much larger than the males, which usually are grey instead of brown. Young individuals are sometimes dark brown and their correct coloring emerges only after a few years. Apart from their gender-specific coloring, there are also individuals that are very dark or almost black. This is caused by a pigment error, melanism, that is apparently not inherited by their young. Black vipers usually give birth (they do not lay eggs) to normal colored youngs, and normal colored vipers may give birth to black vipers. While their camouflage is not as good as the normal colored snakes, the black crossed vipers have an advantage by being able to raise their body temperature more rapidly, which is especially useful after hibernation or in cold climates.

The Crossed Viper is not an aggressive species and when approached by a human, it tends to rely on its camouflage for as long as possible, before trying to escape. It is only when it surprised or provoked that it will try to bite. This is possibly due to the high amount of energy it needs to produce its venom and since it lives mostly in a temperate climate, it needs to conserve energy. Unfortunately its reliance on its camouflage has caused it to become an easy victim for humans and it is now a protected species in most of Europe.