European adder

( Vipera berus )

The European adder is the only venomous snake in Denmark. Its venom is stronger than that of rattlesnakes, but because the amount is much smaller, it’s usually not dangerous to be bitten by the European adder. Most European adders have a beautiful zig-zag pattern on their backs, which is black on males and brown on females. The European adder is diurnal and spends the day lying in the sun in open places. Here it also lies and waits for its prey.

European adder

weight

50-180 g

Habitat

Forest, bog, heath and dunes

Propagation

Northern and Central EU

Diet

Mice, frogs and smaller b

Get to know the European adder

Classification: Reptiles

Order: Scaly reptiles

Family: Viperidae

Distribution: Most of northern and central Europe

Habitat: Forest, bog, heath and dunes

Body length: Male: 40-45 cm; Female: 50-80 cm

Mating season: March

Gestation: 2 months

Number of offspring: 4-18, usually 8-11 each year

Food: Reptiles, mice, frogs and small birds

Habitat

The common European adder prefers sunny, dry, and undisturbed areas with varied vegetation. In Denmark, it is typically found in coastal dunes, heathlands, bogs, open woodlands, and forest clearings, where it can find both cover and sun-exposed spots to regulate its body temperature. It favors landscapes with scattered bushes and trees that allow quick movement between sun and shade

In winter, the adder hibernates in underground burrows, often on south-facing slopes protected from frost. These hibernation sites are frequently reused year after year. In spring, adders gather at mating grounds near the hibernation sites, where males compete for females. After mating, pregnant females move to summer habitats with abundant food and suitable hiding places

The adder is diurnal and often seen basking on warm stones or in sunlit clearings. It is shy by nature and will typically retreat if approached by humans.

Distribution

The common European adder is widely distributed across much of Europe and northern Asia. Its range extends from the British Isles in the west to eastern Russia, Mongolia, and northern China in the east. It is one of the northernmost snake species in the world and occurs as far north as the Arctic Circle in parts of Scandinavia and Siberia.

In Denmark, the adder is a native species, but its distribution is fragmented. It is most commonly found in Jutland and on the island of Bornholm, while it is rare or absent in many areas of Zealand, Funen, and several smaller islands. Many local populations are small and isolated, making them vulnerable to disturbances and changes in the landscape.

On the Danish Red List, the adder is classified as Vulnerable (VU) due to a decline in both range and population size. Globally, however, the species is considered Least Concern (LC).

Djursland

On Djursland, the adder remains relatively common in several areas, particularly within large, connected natural landscapes such as Mols Bjerge and the surrounding heathlands and woodlands. Here, the snake finds ideal habitats with warm, dry slopes, open terrain, and dense ground vegetation, offering opportunities for basking, shelter, and hibernation.

The Mols Laboratory’s grounds within Mols Bjerge National Park are among the places where, with a bit of patience, one might be lucky enough to spot an adder in the wild—especially in spring, when they emerge from hibernation to bask on stones and sun-exposed hillsides. The population here is considered stable, but like many other places in Denmark, the species depends on undisturbed and varied habitats to thrive.

Smaller populations have also been recorded in northern and southern Djursland, particularly near coastal heaths and forest clearings. However, many of these are small and isolated, making them vulnerable to human disturbance, overgrowth, and habitat fragmentation.

The residents

Information will soon be available.

European adder

European adder

weight

Habitat

Propagation

Diet

Habitat

Distribution

Distribution

Djursland

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European adder

European adder

weight

Habitat

Propagation

Diet

Habitat

Distribution

Distribution

Djursland

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Arrangementer

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