Switzerland is home to several snake species. These reptiles are a natural part of the country’s diverse ecosystems, including both venomous and non-venomous types, each adapted to different habitats across the Swiss terrain.
Native Snake Species of Switzerland
Switzerland is home to eight native snake species, two of which are venomous: the Asp Viper (Vipera aspis) and the Common Adder (Vipera berus). Both are small vipers, typically reaching lengths of no more than 70 cm, with stocky bodies and distinct, subtriangular heads. The Asp Viper’s coloration ranges from light grey to brown or orange, sometimes with an irregular zigzag pattern, and its snout often appears slightly upturned. Common Adders display varied colors, including brown, red, or light grey, usually featuring a prominent zigzag stripe; some individuals can be entirely black.
Non-venomous species include several colubrids. The secretive Smooth Snake (Coronella austriaca) is slender, typically 60-75 cm long, with smooth scales and a dark, often crown-shaped, head marking. Grass Snakes (Natrix natrix), including the Barred Grass Snake (Natrix helvetica), are semi-aquatic, growing up to 150 cm, and are recognized by a yellow or whitish collar. The Dice Snake (Natrix tessellata) is another water-loving species, typically 100-130 cm long, with a grey-brown body and distinct dark spots.
The Aesculapian Snake (Zamenis longissimus) is a long, slender snake with a bronze, brownish-green, or nearly black metallic appearance, an adept climber. The Green Whip Snake (Hierophis viridiflavus) is a common non-venomous species, characterized by its greenish-yellow color with black or dark green bands, and is also an adept climber. The Viperine Snake (Natrix maura) is a less common semi-aquatic colubrid that can mimic a viper with a zigzag pattern.
Where to Find Snakes in Switzerland
Snakes in Switzerland inhabit diverse environments. The two venomous species, the Asp Viper and Common Adder, are primarily found in subalpine regions, typically at altitudes ranging from 1500 to 2300 meters above sea level. These vipers often prefer sunny areas with vegetation for cover and dry soil, such as forest clearings, marshlands, heathlands, pastures with hedgerows, and alpine meadows.
The secretive Smooth Snake can be found intertwined among plants for camouflage, sometimes emerging after rain showers. Aesculapian Snakes prefer humid forests and often climb trees, but may also appear in gardens and stonewalls. Water-dwelling species such as the Grass Snake and Dice Snake are found near aquatic habitats like lakes, ponds, streams, and marshes, where they hunt for fish and amphibians. Snakes are often found in rocky open spaces, woodlands, or near water, and residents may encounter them.
What to Do if You Encounter a Snake
Encountering a snake in Switzerland requires a calm and respectful approach. Snakes are shy and will only bite defensively if they feel threatened or are provoked. Maintain a safe distance and never attempt to touch, capture, or provoke the snake. Allowing the snake to move away naturally is recommended, as most will try to avoid human interaction.
In the rare event of a snakebite, particularly from one of Switzerland’s venomous species, immediate medical attention is essential. Bites can cause significant local effects like swelling and pain, and sometimes systemic symptoms, but fatalities are extremely rare due to modern medical care and antivenom availability. The last recorded fatality from a venomous snakebite in Switzerland was in the 1960s. If bitten, remain calm, immobilize the bitten limb, and go to the nearest hospital without delay. Avoid traditional remedies such as binding the wound or attempting to suck out the venom, as these can worsen the situation.