Documentary film about Snakes - Vipers
Adder general - description
Common viper is a snake from the family of viper. It is the most widespread snake in the world, lives in most of Europe and Asia. At the same time, he is the most northerly living snake characterized by extreme resistance to cold weather and the only poisonous snake of the Czech Republic and many other states in the northern part of the Northern Hemisphere. In the Czech Republic, viper is generally classified as a critically endangered species.
Its poison is highly effective on small rodents, but it has only a very small amount, so under normal circumstances, its bruising will not endanger human life - the risk is only for allergic individuals, young children and old and sick people. The lethal dose of the poison is about 15 to 20 milligrams, however, the general adder has an average of about 10 milligrams, and in addition it does not release more than one-third of poison at one stroke. More dangerous is the vampire subspecies Bosnian, who lives in the Balkans and has an atypical poison composition.
Viper is a relatively small snake, adult females grow to lengths up to 60-75 cm, but males are usually up to 60 cm. The largest individuals (almost always female) can measure up to about 1 m, but these are rare cases.  The weight is around 200-300 g. The most common color is gray to blue-gray with a distinct dark curved line on the back, but there are many more or less rare color variants, some of which have no line at all. On the territory of the Czech Republic we can meet the black (morpha prester) and the red form (morpha chersea). The reliable sign, which differs from other Czech snakes, is a sloppy pupil.
Their food is mainly small rodents, amphibians, lizards, possibly young birds and bird eggs, exceptionally bats and little bunnies. In addition to vertebrates, some invertebrates, such as earthworms and slugs, are eaten.
A viper is often referred to as a typical wildlife, but in reality it is a transient state between fertility and animal life, since the eggs are nourished by a primitive placenta of the chorio-allantois type during their stay in the body. It is this adaptation which plays an extremely important role in the exceptional resistance of this species to the cold climate. One female will usually deliver 5-20 pups, respectively. can bear the corresponding number of eggs from which the youngsters immediately club (in our conditions, it happens at the end of August and September). The youngsters are 9-20 cm long.
Viper is a shy snake that flies in front of a person. The snapper turns into a spiral, sows the front of the body and threatens the attacker, or runs headaches against him (usually with a closed mouth and no real intent to bang). But if we step on it, it will quench, sometimes if we try to take it.
The winter season spends the viper in the hibernation state of 30 cm to 2 m underground, in the case of rock cracks can be hidden even deeper. They spring up in the spring (usually in April), and shortly thereafter, mating occurs during which there may be a series of duels among males (so-called "snake dances"). They consist of a variety of pushing and pushing, without the use of poisonous teeth.