Which Spanish snakes are dangerous?

Before we start, there is an important message to keep in mind: the snakes of the Iberian Peninsula are wild animals . It is not uncommon to find snakes in the field, lying in the sun in the middle of a road. Of the 3,500 species of snakes in the world, there are only thirteen in Spain, and of these, only five are poisonous.

Any contact between people and snakes should be kept to a minimum , but not only because of the risk to that person if the snake were to become dangerous, but also to avoid negatively interfering with their behavior. They are animals that are easily stressed , and a disturbance can have an impact on their lives.

So the first rule, with a snake in the field, is to stay away . It doesn’t matter if it’s poisonous or not. The species doesn’t matter. In any case, the priority is to try to avoid her, keep your distance, pretend she’s not there and go around without disturbing her. If anything, photograph it from afar to have a nice memory of the meeting.

As has been exposed, approaching can also be risky. Although most snakes – venomous or not – will generally try to flee before defending themselves, in reality any of the thirteen species of Iberian snakes can, at any given time, respond aggressively and launch a bite. One possible risk is not correctly identifying the snake and assuming a venomous species as ‘harmless’. But, in fact, the snake does not have to be poisonous for that bite to be dangerous.

It is very common that a so-called ‘harmless’ snake bite ends up being spectacular. The wounds it causes, although small, are deep and easily infected. Again, the best way to avoid it is to stay away. Do not disturb them, and if you find her by chance, simply avoid her and each one for his own.

snakes without poison

Of the 13 species of snakes in the Iberian Peninsula, eight do not have poisonous glands. All of them are under a special protection regime , according to the Spanish Catalog of Endangered Species .

Among them, the yellow-green snake ( Hierophis viridiflavus ), predominant in areas of the Pyrenees, and the horseshoe snake ( Hemorrhois hippocrepis ), much more widespread. The collared snake ( Natrix natrix ) is a very cosmopolitan species that can be found in practically all the peninsular provinces. The viperine snake ( N. maura ) belongs to the same genus, a deceptive snake, because the shape of its head resembles that of a viper. Its mimicry with the viper serves as a good dissuasive method.

Two other species belong to the genus Coronella : the southern smooth snake ( C. girondica ), also widespread throughout the peninsula, and the European smooth snake ( C. austriaca ), predominant in the northern half, although with some populations in the provinces. of Albacete and Granada.

To conclude, the two most iconic snakes of the Iberian Peninsula: the ladder snake ( Rhinechis scalaris ), with its characteristic horizontal lines on its body, and the Asclepius snake ( Zamenis longissima ), the longest of the Iberian snakes, with a length that can exceed two meters. This is the snake that is part of the symbol of medicine and pharmacy, in honor of the Greek god Asclepios.

Two poisonous snakes

Two poisonous species of snake stand out in the peninsula. Both, also, under a special protection regime in Spain . The most abundant is the so-called bastard snake ( Malpolon monspessulanus ), distributed throughout almost the entire territory, with the exception of the Cantabrian coast. It can reach two meters in length, like the Asclepius snake, although it is even more massive. One difficulty of the bastard snake is the position of its fangs set back in the back of the mouth, making it difficult for a bite to inoculate its venom. In addition, it is less powerful than that of vipers.

The hooded snake ( Macroprotodon cucullatus ) is much smaller, barely half a meter, and is unmistakable because of its dark collar, which usually also covers its head. It is usually nocturnal, and its venom is also not very powerful, although it can paralyze small mammals and birds on which it feeds.

the three vipers

Among the Iberian snakes, the three native species of vipers are the most dangerous. Its venom is more powerful than that of snakes and can cause serious health problems for people and animals. Each of them has a defined distribution, and they overlap very little with each other, something quite characteristic of vipers.

The most widespread is the snout viper ( Vipera latasei ). It can be found in practically all provinces, with the exception of La Coruña, Lugo, Asturias, Cantabria and the three Basque provinces. However, its population is relatively low, and it appears to be rare throughout its range. Herders and walkers continue to kill these animals when they find them, and they are frequently run over on the roads.

The International Union for the Conservation of Nature (IUCN) classifies the snout viper as ‘vulnerable’, and the Spanish Catalog of Endangered Species includes it as a species under a special protection regime.

Distributing throughout the Pyrenees, and extending to the south of the Basque Country, La Rioja, Burgos and the north of Soria, we have the second Iberian viper, the asp viper ( Vipera aspis ). Unlike the previous one, this species is in a much more favorable conservation status, which makes it cataloged by the IUCN in the status of ‘least concern’.

Throughout the Cantabrian coast, from the north of Navarra to the Atlantic coast, and also throughout Galicia and a large part of the province of León, we find the third species: the Seoane viper ( Vipera seoanei ). Although it is the only viper endemic to the Iberian Peninsula —that is, it does not occur naturally outside this region—, its conservation status is also significantly better than that of the long-snouted viper. The IUCN classifies it as ‘least concern’.

References:

IUCN. 2022. The IUCN Red List of Threatened Species. Version 2021-3.

Royal Decree 139/2011, of February 4, for the development of the List of Wild Species under Special Protection Regime and the Spanish Catalog of Endangered Species, Pub. L. No. Royal Decree 139/2011, BOE-A-2011- 3582 20912 (2011)

Pleguezuelos, JM et al. (Eds.). 2004. Atlas and red book of amphibians and reptiles in Spain. Autonomous Body of National Parks.