Published 15.54
The heat is here and now the vipers are waking up. Scandinavia’s only wild venomous snake is found from north to south. There are tricks to avoid being bitten by it. But for those who get a stab, there is only one piece of advice – seek medical attention immediately.
– Don’t wait, says Peter Hultén at the Poison Information Centre.
When the heat comes, calls about viper bites to the Poison Information Center increase. So far this year, they have received just over 100 calls. The advice is always the same – seek medical attention immediately, even if you feel fine.
– If you are close to a hospital with an emergency department, you can go there, otherwise call 112, says Peter Hultén, pharmacist at the Poison Information Centre.
If you encounter a snake out in nature, the best thing to do is to stand still and wait until the snake has run away, or to calmly walk away. The snakes are not very curious about us humans.
– As long as you don’t step on the snake or grab it, there is no risk of being bitten, says Johan Nylander, herpetologist at the National Museum of Natural History.
Stomping the ground can certainly scare the snake away, but there is an additional trick – imitating one of the snake’s natural enemies.
– If you stand and flap your arms, it’s even better. It resembles flapping birds. If there is anything flapping, the snake takes cover, says Johan Nylander.
400 a year
How serious a viper bite is depends on how much venom the viper has injected. In some cases, it is a so-called dry bite, in which case no poison has arrived at all. But since it is impossible to know, you have to go to the health care. The viper’s venom is very potent. Some get only a minor swelling while others get very sick.
– Early symptoms can be dizziness, nausea, abdominal pain and vomiting. But there can also be a sharp drop in blood pressure, breathing difficulties and reduced consciousness, says Peter Hultén.
The swelling at the bite site can spread and affect the entire bitten body part. Anyone who gets severe symptoms needs an antidote, a viper serum.
– Serum is available in almost all emergency hospitals and is often very effective. If you just go to the hospital, there is usually no danger, says Peter Hultén.
Although the situation may feel stressful, the person who is bitten must remain calm and still. This reduces the risk of the poison spreading quickly in the body.
– The person who is bitten should preferably have company and not drive alone because you can quickly become much worse.
Thanks to the antidote, deaths are rare. The last death reported was in 2023, the person bitten by the viper had not then sought hospital. But around 400 people a year are treated in hospital after being bitten.
A changed climate
Vipers can be found largely throughout Sweden. Their status is viable, i.e. a stable population that is not judged to be endangered. But there are some worries.
Because even though the vipers are fond of warmth, a warmer climate is not something they benefit from. Less snow and warmer winters offer less opportunities for winter rest. The snow cover acts as insulation and without it the snakes are more sensitive to cold snaps. They are very inactive during the winter and probably have difficulty moving to warmer depths if required.
Small rodents, one of the viper’s favorite foods, also find it harder to overwinter safely in warmer climates. In winter, they lie dormant in the cavity between the snow cover and the ground.
– You have seen that the environmental change is stronger the further north you go. These northern vipers may live dangerously, we don’t know that, says Johan Nylander.
Studies show that the number is decreasing in some parts of Europe, mainly because their natural habitat has been exposed to human influence. There is no corresponding study for the Swedish population, according to Johan Nylander.
Myth about the kids
During May, many vipers lie still in the sun and warm up, preferably on a rock or hiding in tall grass or in other places where it does not easily become prey for other animals. In June, July and August they hunt their prey and are more active. When autumn comes, they retreat and hibernate.
The males are the first to wake up after winter. When the females arrive, about three weeks later, it is time for mating. In August and September, the baby vipers, aspens, are born. That they would be more dangerous is a myth. Their venom fangs are shorter and they have a weaker bite. They also inject less venom.
Nor are they more approachable or fearless.
– Rather the opposite. They are always keen to evade, says Johan Nylander.
Be sure to look
Whether it will be a “viper wound” or not is difficult to answer. Studies indicate that less food for the vipers, for example due to a year with fewer rodents, increases the risk that they will not survive the winter.
Johan Nylander is perhaps, as he puts it, “biased” but hopes that more people will get the chance to see one.
– I have met people who have never seen a viper, even if they moved in nature. So I would say that it is very rare that you have a chance to see one. Therefore, you should take care to look, he says.
Viper
The viper, Scandinavia’s only wild venomous snake, is found throughout Sweden, even north of the Arctic Circle, but not the farthest north and on the highest mountain peaks.
It is characterized by its zigzag pattern along its back, which is black on males and dark brown on females. The basic color is gray and brown or reddish-brown, but completely black individuals occur. The species usually grows up to 65 centimeters long, but the female can grow longer.
The viper thrives, among other things, in bogs, heather heaths, forest edges, roadsides, meadow and field edges, but avoids dense forest as it is dependent on places with high solar radiation.
In mild and warm springs, the viper can emerge as early as February, otherwise usually in March-April.
If you are bitten by a viper, you should always seek medical care and a bitten pet should always be checked by a veterinarian.
Sources: SLU Art data bank and Animal care guide
If you get bitten
When someone has recently been bitten by a snake:
Call 112.
Calm the bitne, who may be afraid or anxious.
Rest and keep the bitten body part still.
Remove rings, shoes, bracelets or similar as the area may swell.
Leave the place of begging alone. Do not try to suck out the venom, cool, heat or tighten a belt or similar around the snakebitten body part. It can worsen the course.
Sources: Swedish Medicines Agency, 1177
