Four species in the Ländle

Automatically saved design

The adder is the only venomous snake in the whole of Vorarlberg.

(Bild: Naturschutzbund Österreich / Wolfgang Schruf)

Snake sightings make many people feel uneasy. They are extremely shy hunters that avoid humans wherever possible. There are four species of snake in the country - and only the adder is poisonous. But how dangerous are they really?

They are usually shy and live in secret. They avoid humans wherever possible. In terms of evolutionary history, snakes are very old animals that have conquered almost all habitats on earth - thanks to their high adaptability and a range of special sensory organs.

Today, however, many species are threatened with extinction, and the native reptiles are also on the "Red List". In Vorarlberg, these include the adder, grass snake and smooth snake. Since the barred grass snake was recognized as a separate species by scientists in 2017, the Ländle has gained one more snake species.

The barred grass snake has only been a separate species since 2017.

(Bild: Naturschutzbund Österreich / Alexander Oberpilchler)

"For a long time, it was assumed that the barred grass snake was merely a color morph - it was considered a subspecies of the common grass snake," says Carolina Trcka-Rojas, amphibian and reptile expert at the Austrian Nature and Biodiversity Conservation Union. However, studies by an international team of scientists have shown that there are genetic differences between the two snakes, explains the expert. This means that the barred grass snake is now considered a separate species.

Sightings mainly in the south of Vorarlberg
Its exact distribution area is still being investigated, but the fact is that there is confirmed evidence of this rare species in Vorarlberg. According to the "Red List" for reptiles (2021), sightings have mainly been reported in the southern Rhine Valley, Walgau, Montafon and Klostertal. "The barred grass snake has a series of conspicuous, transverse black spots on the side of its body, which are shaped like bars. This clearly distinguishes it externally from the grass snake," explains Trcka-Rojas.

In Vorarlberg, the grass snake is mainly found in valleys and near bodies of water. Its back and flanks are bluish-grey in color, with irregularly arranged black scales. Both snake species are non-poisonous. In danger or stressful situations, the animals often play dead if there is no possibility of escape. This reflex is known as tanathosis.

The grass snake loves valley locations and proximity to bodies of water.

(Bild: Naturschutzbund Österreich / Naturkundestation Linz)

The smooth snake behaves somewhat differently in this respect. It remains motionless and relies on the fact that its good camouflage allows it to visually blend in with its surroundings. However, if it feels cornered and threatened, it curls up in a plate shape and raises its front body. In continued distress, the snake tries to bite the attacker. "However, the animals often launch a mock attack without actually biting, and their teeth can barely penetrate human skin," says Trcka-Rojas.

The smooth snake is also known as the smooth snake.

(Bild: Naturschutzbund Österreich / Roger Jagersberger)

The non-poisonous vipers are often confused with Vorarlberg's only poisonous snake - the adder. "The smooth snake has a dark spot on the top of its head, otherwise its coloration is less pronounced than that of the adder. Their scales are close together, which makes them appear shiny and almost moist," describes the reptile expert.

Another important feature: the smooth snake has round, friendly-looking pupils, while the adder, like all vipers, has vertically slit pupils. "The adder is a rather cold-loving species, which is quite unusual for snakes," emphasizes Trcka-Rojas. It therefore prefers mountainous regions and climbs to altitudes of over 2000 meters.

As an adaptation to these living conditions, the adder is viviparous, as the temperatures in mountainous regions are not normally sufficient to hatch eggs. The reptiles bridge the winter by looking for suitable hiding places and going into torpor for several months. According to the reptile expert, this snake species is one of the losers of climate change.

Facts & figures

• Snakes have no external ears; they perceive vibrations via their lower jaw. The sound waves are translated into nerve impulses in the inner ear and transmitted to the brain. This enables the reptiles to detect prey even from a great distance.
• The characteristic forked tongue is used to capture scent molecules from the air and transport them to the olfactory organ in the roof of the mouth.
• Snakes choke down their prey whole by unhinging their lower jaw. After an extensive meal, it can take several weeks before the snake hunts again.
• Venomous snakes produce their venom in a gland at the back of the head. It can be injected into the prey through the two hollow fangs when it bites.
• All native snake species, just like other reptiles, are strictly protected and some are highly endangered.
• A near-natural garden or even just the creation of piles of branches or stones in the garden creates habitats for snakes and other small animals.
• Snake observations can be shared on the citizen science platform naturbeobachtung.at or on Observation.org, for example.

The animals did not have it easy in the past either, as Trcka-Rojas reports: "For a long time they were actively hunted, there were even separate guilds for them." The reason for this was probably that the viper is a poisonous snake. However, the adder only poses a real danger in extremely rare cases. The adder will normally always flee from humans, emphasizes Trcka-Rojas.

However, if a bite does occur, for example because a person has accidentally stepped on a snake, this is not life-threatening for an otherwise healthy person. "People who have been bitten compare the pain to that of a wasp sting. However, a doctor should be consulted to be on the safe side, as dizziness can occur under certain circumstances. Often, however, the snake does not use its venom in its defense and tries to get out of the situation with a warning bite."

Snakes: useful and inconspicuous
In any case, such unfortunate incidents are not common. Snakes may seem scary to many, but they are an important part of the ecosystem because they decimate rodents, for example, and are also prey for other animals, such as birds of prey.

The nature conservation expert emphasizes the usefulness of the animals with an example: "If you have an adder as a garden resident, you will hardly notice its presence, except that the population of voles is rapidly decreasing."