The pull of the Danish wilds can be hard to ignore. After checking off the Tivoli Gardens and the hip downtown core of Copenhagen, you might want to venture out to see the Baltic beaches and the wooded reserves of Funen. But what about the critters you might encounter? What about snakes in Denmark?
Cue this guide. It has the lowdown on all the serpent species in this design-mad, uber-cool country. It will detail what to look out for to identify certain snakes in Denmark, how to tell the dangerous ones apart from the harmless ones, and where you’re most likely to come across the various sliders out there.
There aren’t actually all that many snakes in Denmark. Official estimations say that the country only hosts a handful, but there are also one or two that live really nearby in Sweden or Germany that you might spot during your travels. There’s also only one that’s truly venomous. Let’s take a look at the lot…
European adder (vipera berus)
The European adder is the only venomous snake in the home of Hans Christian Andersen. That’s actually the case for a great many northern European and western European countries, because this member of the viper tree of snakes has a geographic range that sees it pop up in places as diverse and variegated as Normandy and Russia, the borderlands of northern Greece and the fens of England.
They are also found on every single island of Denmark and the mainland peninsula of Jutland. Most active during the early summer months, they like to bask on open hiking trails, a habit that often brings them into contact with walkers and ramblers. They generally like to live in relatively low-altitude settings, usually along the coastline in sand dunes and hilly landscapes, though they can also be found inland in swamps, wetlands, and in pre-mountain ranges up to 3,000 meters.
Vipera berus are notable for having a bold and distinct patterning that runs the whole length of the body. It does vary depending on the region, but it’s often a series of diamond-like geometric designs picked out in light yellow running on a background of dark black and brown. The bite, thankfully, isn’t as strong as other members of the viper genus. It can be fatal to humans but there’s only been one recorded death from an adder in Denmark in the last half a century.
Grass snake (Natrix matrix)
The grass snake has many names. Some know it as the ringed snake, others as the water snake or the common water snake. Whatever you call it, it remains one of the most common snakes in Denmark. Don’t let that worry you too much – they are completely non-venomous and pose virtually no danger to humans at all. In fact, they survive mainly on a diet of small insects and toads, though will also devour ant larvae and frogspawn given the cance.
This common colubrid snake can be spotted for the line of yellow that rings the point where the head joins the body. It’s clearer in some individuals than in others and every snake has a unique block pattern of black squares on the underside. The main coloring on the top of the grass snake is green, which helps them to hide away in their favored habitat of meadows and riparian fields.
Contrary to what the name implies, grass snakes are actually fantastic swimmers. They’ll happily spend a lot of time hunting in the water. When the colder months swing around – and it will get pretty cold in this corner of Scandinavia – they will typically go into long-term hibernation in a pre-made underground burrow that helps preserve warmth. The main mating season is in the midsummer of June and July, which is when you’re most likely to spot one during your Danish travels.
Aesculapian snake (Zamenis longissimus)
There’s a lot of evidence to show that the Aesculapian snake is now 100% extinct in Denmark. However, there’s also evidence to show that they were once extremely widespread throughout Central Europe and Scandinavia. Specimens were observed in this corner of the continent as late as the early 19th century and there are fossilized remains that show they had thriving population numbers on the islands between the Baltic Sea and the North Sea some 5,000 years ago.
What we’re trying to say here is that if you do happen to spot one of these guys during your travels in Denmark, then it will be a rare occurrence. Like, super rare! You’re looking for a relatively long snake that has the ability to grow to a whopping two meters or more at full adulthood. They have a similar yellow collaring that means they often get confused with the Natrix natrix (see above), though that often spreads out as snakes grow into a longer pattern of circular spots picked out in mustardy yellow.
The prime habitat for the Aesculapian snake is moderately vegetated hilly areas. However, they also like to inhabit areas that have a variety of ecosystems within easy reach, from clearings to dense broadleaf forests to rivers and lakes. Their diet consists largely of small- to medium-sized rodents, which they incapacitate in the same way as the famous boa constrictor: Suffocation. Badgers and other, larger, snakes are these guys’ main predators.
Smooth snake (Coronella austriaca)
The smooth snake is another of the serpents that experts think is now actually totally extinct in Denmark. However, like the Aesculapian snake before it, there’s evidence to show that they once lived in great numbers in this southern part of Scandinavia. Most notably, there are currently populations in the neighboring German region of Schleswig-Holstein, and just across the Baltic straits in Sweden. In fact, it’s a bit of a puzzle that they aren’t still around in Denmark to boot.
So, let’s just say there’s a chance you could encounter one of these, though it is a small one. Here, you’ll want to keep the eyes peeled for a creature that can measure up to 90cm from snout to tail, though most are around 50-60cm in all. The coloring is brownish grey with stripes of darker olive green and brown running away from the head. And you get a distinct sideline marking on the head itself, like stripes on a racing car.
Smooth snakes actually do pretty well for themselves in Europe. They aren’t venomous but they are adaptable. From the edges of Iran all the way to the UK, they can adopt habitats as varied as heathland and low-lying mountain ranges. They typically feed on other reptiles though only hunt animals smaller than themselves. It’s another example of a constrictor snake, which means they subdue prey through strangulation and squeezing.
Slow worm (Anguis fragilis)
Okay, so we’re cheating here a bit because the fifth and final member of our guide to snakes in Denmark isn’t really a snake at all. It looks like a snake. It moves like a snake. It’s often mistaken for a snake. But it’s actually a lizard. A lizard without any legs, mind you. Still, it’s worth having here because there’s a good chance that you’ll come across one of these curious creatures if you venture out into the Danish countryside since they are pretty common, especially in the summer months when they emerge from burrows to bask in the sun.
There are actually five separate sub-species of the slow worm in Europe. The one that lives in Denmark and broader Scandinavia is known by the Latin moniker Anguis fragilis sensu stricto. It’s the original version of the animal, sporting that trademark smooth body that grows up to 60cm in length, getting progressively narrower as it moves from the base of the head to the tail. The coloring is perfect for a critter that likes to camouflage itself in woodlands and near rivers – think dark, dusky brown and black the whole way along.
As you’d expect, slow worms aren’t venomous and pose little to no threat to humans at all. In fact, they are often encouraged into gardens by green-fingered inhabitants because they help to reduce the number of pests that can damage crops. They don’t seem to need venom either – slow worms are widely considered to be the longest-living lizard on the planet. Some individuals in captivity have managed to reach the venerable age of 30!
Snakes in Denmark – our conclusion
There aren’t really all that many snakes in Denmark. There’s no overload of fearsome vipers a la Thailand or Australia here; just a handful of curious serpent species. The sole venomous snake in Denmark (the adder) is actually pretty common all over the continent and is the sole venomous snake in oodles of other European nations besides. Then you have the common grass snake and a couple of other species that might or might not be totally extinct in this part of Scandinavia.