2016

Viper - the only venomous snake in Latvia

Every year nature friends are reminded to be careful when in the forest and be aware of snakes, especially during the mushroom- and berry-picking season. Please follow the instructions for how to avoid snakes and what to do if a snake has bitten.

All reptiles, including snakes, are poikilotherms. They use heat from the environment in order to warm their bodies. The most pleasant temperature for snakes in Latvia is from +22 to +27°C. Only three species of these vertebrates live in Latvia’s chilly climate:  viper, grass snake and Coronella austriaca (commonly known as the smooth snake). Only one of them is venomous - Common European adder (Vipera berus).

Viper – the only venomous snake in Latvia

The viper is a quite small reptile (an adult snake is only 60-75 centimetres long) and compared to other snakes in Latvia – pretty squat. It can be silver-grey, dark grey, brownish-grey brown, reddish-brown or beige with a dark pattern across the whole body. The trapezoidal head has an X or V-shaped „crown”. The colour of the bottom can vary. Usually it is black, grey or brownish-pink, it may have a pattern. However, there are also rare cases of completely black specimens whose typical pattern on the back and head is invisible. Rarely, there are also some self-coloured red exemplars without a pattern.

It is possible to distinguish males from females by comparing tails, namely, females have a shorter tail and the top of it is slightly yellow on the bottom. For males this part is pinkish.  Viper females usually are portlier than males.

Vipers are common in the whole territory of Latvia, but their population is not evenly spread. They concentrate in areas with plenty of food and places to hide, and with rare chance to meet a predator. These reptiles gather together in great numbers during the spring mating period.

Vipers are the most cold-resistant snakes in the world. They are present at places farthest away from the Equator; they even live above the Arctic Circle. Due to their cold resistance, they are the first ones to come out of wintering areas. Males appear before females. Soon after waking up from the winter sleep, at least four-year-old males fight over at least four to five-year-old females. In early spring, while nights are still chilly – in April, and the beginning of May, vipers are active only in daytime. Later, when it’s getting warmer, they become quite active also in twilight and at night. However, it does not mean that they do not appear in daytime. Basking in the sun is especially important for females before giving birth to their babies in late summer, around the mushroom-picking time.

They bite if disturbed

Particularly in the time of picking mushrooms, there’s a bigger chance to come across a viper snuggled in a sunny place. If you do not flee but examine the animal carefully, this is what you will see: the snake has fixed eyelids – they have grown together; that is why a false belief was made that snakes can hypnotize. Vipers also have protruding “eyebrows” that create a look of an angry reptile. However, if it is not disturbed, the snake is neither angry, nor aggressive towards humans. And even if people annoy it, the reptile will try to get away on the first place. However, if it is not possible, the viper straightens up and curves the front body, and hisses as a warning. The disturbed animal flicks its black, slim, flexible and top-spitted tongue. It’s an olfactory organ. The snake tries to scent who and where the intruder is. The tongue gets out of the mouth through the special gap in the “upper lip”, then for a while it quickly vibrates and catches molecules in the air and then takes them back in the mouth to a specific analyser in the upper jowl.

So, the reptile hisses and flicks its tongue. However, it is not about to attack. Snakes do not eat people. The viper never (!) attacks first. It bites only if provoked by, for example, scaring, chasing, touching with a boot, hand, or when someone steps, sits on it or touches. The animal is most intolerant during the mating season and when it is changing the upper layer of its skin.

Even though all snakes are deaf, they perfectly perceive every single vibration. That is why most of the reptiles timely feel when people are approaching and manage to disappear in a cave, a bunch of twigs or a pile of rocks. However, there are situations where due to some reason they cannot hide. The animal simply stays lying on the ground motionlessly hoping that it won’t be spotted.

There is not much of venom

The venom is a really precious asset, vipers get food using it. It is meant not only for killing their victims; it also takes part in the digestive process. Vipers need a long time and energy to restore their venom reserves; therefore, the viper uses it very economically.

The venom is injected by biting, using two, approximately half a centimetre long, hooked venom teeth. They are meant for capturing frogs, lizards, rodents, small birds and bugs.

This, in fact, clumsy animal isn’t able to make any kind of jumps. While biting the victim, the viper simply straightens the previously curved body. In order to catch a victim safely and precisely, the distance between them has to be no bigger than the length of the snake. If the viper moves forward or lies straight, it can bite only on sides or back.

The venom is injected in the victim’s body through the channels in the teeth that open in the front. Usually the snake keeps both its venom teeth hidden. At the moment of biting the mouth is widely open and teeth just like in hinges move forward and then vertically. First teeth to touch the victim are the small, non-poisonous ones. They lean on the victim’s body helping the venom teeth get deeper in the flesh. The maxilla is very flexible; it can move up to 90° around its axis. It not only makes biting easier but also helps getting food into the throat. When the victim is poisoned, the viper cannot start eating it at once because the victim manages to move a little bit before dying. The reptile finds its fled “dish” by scenting its traces. 

Viper’s venom is a specific mixture of toxic elements that contains protein-degrading enzymes. It spreads through the blood vessels, destroys capillaries by creating trombs, the heart is also traumatized by creating brusing and swelling that slowly spreads across the body.

If, however, the viper has bitten

If the viper has bitten a person, there will be teeth marks – two small, bleeding points with a redness and swelling around them. Usually the bitten place hurts at the beginning, later it gives a burning sensation. The person feels anxious, the breathing becomes difficult,  tachycardia can appear, sickness, cold sweat. In more complicated cases of intoxication the victim may feel weak, sleepy, get fever, dizziness, the heart rate and pulse slow down; there may also be vomiting and nightmares.

The consequences depend on the part of the body where the snake has bitten. The closer to the head or heart, the more dangerous it is. However, cases of death in the Northern hemisphere are very, very rare.

If the snake has bitten, try to stay calm and move as little as possible because venom spreads faster when the heart rate accelerates. First, call the ambulance or take the victim to the doctor. If you are alone, try to get to medical assistance yourself. Do not rub or massage the injured place so the venom does not spread that quickly. Drink a lot of water in order to “dilute” the venom. Do not use alcohol in any circumstances! Never put on a tourniquet or bandage, since it can cause tissue breakdown. Do not try to suck out the venom, cut or cauterize the site of the bite.