Snakes in the Wienerwald

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The Wienerwald (“Vienna Woods”) is a large hilly and forested conservation area west of the city of Vienna, the capital of Austria. It is home to four native species of snakes, all of which are non-poisonous and harmless to humans.[1] It is not uncommon to spot some of them on a walk through these woods.

Smooth snake

The smooth snake (Coronella austriaca) is often mistaken for an adder, due to its similar color and patterning. However, the smooth snake is much smaller and thinner, rarely growing longer than about 50cm, and has a very distinct pattern on top of its head. Unlike most snakes, the smooth snake does not lay eggs, but gives live birth to its young. It tends to be quite shy, and is not easily seen.

A smooth snake with a distinct pattern on its head.

Aesculapian snake

The Aesculapian snake (Zamenis longissimus) is by far the largest of the four Wienerwald species, or in all of central Europe for that matter. Adults generally grow to about 1.5m in length, but specimens of up to 2m have been found. These snakes are excellent climbers, and can often be found in trees, or even on the roof of garden sheds. They have a shiny olive-green to dark-brown back, with a light-yellow belly.

An Aesculapian snake with a dark brown back and distinct yellow belly.
An Aesculapian snake with a more olive-green back.

A juvenile Aesculapian snake is easily confused with the grass snake (Natrix natrix), another one of the four native Wienerwald species. This is because of the yellow “collar” around its neck (similar to that of an adult grass snake) and a distinctive patterning on its back, both of which disappear when the juvenile becomes an adult.

A juvenile Aesculapian snake with a yellow “collar” and distinct patterning on its back.

Not a snake!

The fourth Wienerwald species is the dice snake (Natrix tessellata). However, it often happens that the slow worm (Anguis fragilis) is mistaken for yet another snake species. Slow worms are very common in the Wienerwald, but they are actually legless lizards! Over the course of their evolutionary history, they have lost their legs entirely and therefore look and move like a snake. But they tend to be smaller and more smooth and shiny with non-overlapping scales. A typical lizard characteristic that they have definitely not lost, is shedding their tail to escape from predators.

A slow worm in the Wienerwald.

Common European adder

Besides the four non-poisonous species that also occur in the Wienerwald, there are two more snake species native to Austria as a whole.[2] Both are vipers, i.e., venomous species. One of them, the (nose-)horned viper (Vipera ammodytes) occurs only in the southernmost part of the country, along the border with Slovenia and (partially) Italy. The other one, the common European adder (Vipera berus), can be found throughout most of central and western Austria. It is easily recognized by the distinct dark-brown or black “zig-zag” pattern on its back.

A common European adder in the foothills of the Austrian Alps.

Strangely enough, though, members of this species that live higher up in the mountains are often completely black! Once I almost stepped on one during a hike. As it quickly moved away from the trail, it was hissing aggressively.

A completely black common adder in the Austrian Alps.

A seventh snake species that used to be present in the eastern part of the country, the meadow viper (Vipera ursinii), has not been observed in over 40 years, and is now presumed extinct in Austria.

References

  1. Biosphärenpark Wienerwald Management. Schlangen im Wienerwald.
  2. Stella Haller. Schleichende Gefahr? 7 Schlangenarten in Österreich. Blühendes Österreich, 15 July 2020.