The Adder (Or European viper) – Vipera berus

An adder in vegetation.
The adder (Vipera berus berus) I saw! I would say young, but not a baby. About 30-40cm in length. Excuse quality, as often mentioned I use a £60 mobile phone’s camera and had to keep my distance. I’d have loved a better shot but it’s not worth the risk to the adder or myself. But oh! My face when I saw it! I was smiling the whole rest of the journey and imagine my elation when I saw a grass snake later in the day! (Credit: Me)

Oh, be still my beating heart! What a day.

Adders are gorgeous snakes. Unbelievably pretty and exotic looking for what is the most northerly distributed member of the viper family. They are a short, stout snake, maximum length here in the UK is around 80cm (slow worms can be longer!) with a weight of up to around 120g. They can be easily distinguished by the zig-zag pattern, almost a series of connected diamond shapes, across their back. They also exhibit sexual dimorphism (differences in appearance between sexes) with males tending to be paler, more grey in colour with more distinctly dark markings, whilst females are a tan or golden brown and often have dark-brown markings.

two adders coiled in dry bracken.
Almost certainly a mating pair of adders. Showing well the difference in colour they can exhibit. The male is likely the one on top (ooh err!) with the paler, more silver-grey colouration and much blacker marking. The female on bottom (this is not supposed to be sexual, I swear!) is a more tan brown with paler, more dark-brown markings. (Credit: © Copyright Andrew Curtis and licensed for reuse under this Creative Commons Licence.)

There is also a melanistic form, the black adder, no not that one!

Like many of the UK’s reptiles adders are most active between spring and late summer, emerging from their overwintering in April or May and disappearing again by October. However research into their behaviours appears to show an increase in their activity caused by climate change, as milder winters in Northern Europe see them being spotted and active year round.

This is concerning as adders are shy, retiring things. Their preferred habitats are mixed and complex, most associated with coastal sandy soils, heaths or moors with plenty of cracks and crevices, grass, plant cover, hedges etc. in which to hide and find their prey. In winter there is significantly less cover putting them at increased risk of competition with other adders, predation, persecution by people, and us accidentally stumbling across them when out walking the dog.

A hedgerow. A small butterfly is on a leaf in the centre and just below you can barely make out the markings of an adder.
Typical adder habitat, basking in the sun off to the side of this dusty walking path. I had actually stopped to photograph the butterfly and didn’t even see the adder at first! See if you can spot it. Either way a good example of just how shy these guys are. (Credit: Me)

Their overwintering is an interesting thing to note, too. Many people will refer to it as a ‘hibernation’ using that as a catch-all term for any energy-conserving over-wintering behaviour. However hibernation occurs in endotherms – warm-blooded animals. Ectotherms – cold-blooded animals – go through a process known as ‘brumation’.

Brumation is very similar to hibernation, a slowing of metabolism, heart rate, respiration etc. to conserve energy and stay alive. However hibernation is a very passive process, a warm-blooded animal is generally in a state of sleep and will not stir. Brumation can be more variable such that on warmer days animals like our adder can venture out, often to get water but also to forage a bit of food should the opportunity arise.

Adders are also surprisingly unpicky in their diet, with much of it being dependent on their local habitats. Their preferred meals seem to be small rodents, other reptiles like lizards and slow worms, and frogs and newts. However there are reports of them eating birds, climbing into nests to eat eggs, enjoying a worm, an insect or a spider or two and much more besides. A true testament to their bad-assery is the fact that they have been observed preying on weasels! I plan to get around to covering the weasel family, the mustelids, one day but the main thread that runs through all of them is you don’t fuck with mustelids!   So adders seeming to have a pattern of eating them, even if not a regular part of their diet, is a testament to their prowess as a hunter.

An adder eating a weasel.
An adder eating a weasel! (Credit: Bringsøe (2019) Observation of Adder, Vipera berus preying on Least Weasel, Mustela nivalis, an overlooked feeding habit – Used without permission under fair use.)

As mentioned adders tend to emerge from their brumation around April, and one of the first things on their mind seems to be “My word, I’m horny!” and I sympathise. As a result adder breeding season is the same as their emergence season, in April/May. That’s when they add more adders. Their genus name ‘Vipera’ is a huge clue as to how they give birth. It comes from the Latin terms ‘vivus’ as in ‘living’ and ‘parere’ as in ‘to beget’, or give birth. We’ve seen this combination before in both the common lizard and the slow worm who are ‘viviparous’ species. This means that they incubate their eggs internally and give birth to live young. Adders give birth to little tiny live baby adders. Cute!

Now being from the UK it is difficult to talk about adders without talking about their reputation. We are blessed (or cursed from a biodiversity perspective) with very safe wildlife in the UK. The potentially dangerous species that once existed here were mostly driven to extinction hundreds or thousands of years ago. Being our only native venomous snake this makes the adder one of the few species on these isles capable of doing a person any significant harm. So should we be worried?

A close up of an adder's face with prominent red eyes.
This grumpy looking face reflects the fact I couldn’t find good images of baby adders! But my, what a beauty! (Credit: Mick E. Talbot CC-BY-SA-3.0)

I will say cautious, yes, but worried, no. Adders, as I have mentioned, are very shy and are far more likely to slink off to get the hell away from you than they are to chase you across a heath to give you a nip on the ankle. I have seen two adders in my life, one of which played dead and one of which was quite comfortable until it noticed me, coiled up, and buggered off!

Bites are common, though, with around 1,000 events per year, mainly due to the broad distribution of adders across quite human-dense habitats. The adders I have seen are on common walking or cycle paths, for example. However it is most likely to occur when the element of surprise is present in both parties! A person will not notice an adder and suddenly an adder will have a foot in its face and feel immediate danger, responding the only way it knows how to get you to move the hell away! Where surprise is not the factor provocation seems to be a common cause, with people getting far too close to the snakes, even attempting to handle them, causing the snake great distress and a nasty bite to the fool who thought it was a good idea to bother an adder.

Their venom is potentially lethal, but is actually not that potent so deaths caused by adder bites are exceedingly rare. I believe there are only a dozen or so deaths by adders in the last 100 years in the UK, the last one being a 5 year old in 1975. So their frightening reputation is somewhat undeserved.

That said it is not a situation to be underestimated, either. In the young, elderly or clinically vulnerable the situation is direr, and these groups are at significant risk of harm. Cases of anaphylaxis – the same kind of severe reaction you may have with a life-threatening allergy – have been known to occur due to adder venom. Even in healthy adults adder envenomation can be painful and debilitating and cause prolonged pain, limitation or disability. So if you are bitten, or suspect you have been bitten, by an adder you should seek immediate medical attention.

An adder biting a leather glove, showing its fangs.
This handler is sensibly wearing thick leather gloves. As you can clearly see an adder’s fangs are not particularly long. The best protection against adder bites is to make sure if you are out walking where adders may be, ensure you are wearing sensible clothing. A sturdy pair of ankle boots with thick socks can do a lot to mitigate the potential harm of a bite. (Credit: Piet Spaans, CC-BY-SA-2.5)

The best way to be adder safe – to keep you and adders safe – is to be aware of them. In my Grown-Ups Guides: Hedge Hunting article I made note of the fact that even in summer I may go out dressed in thick jeans, ankle boots, a thick long sleeve top etc. and prevention of injury, from the environment and from wildlife like adders, is the reason for this. They are small snakes, with relatively short fangs made for puncturing small animals not a leather boot with thick socks under it! Mind your step and be aware that adders are widespread across the UK and could be in any verge, crevice or hedgerow.

It is a huge privilege to see an adder, so if you do see one keep your distance. Do not bother the snake, disturb it, get too close to it and for the love of all that is serpentine do not try and touch the poor creature! Your idiocy, should you get bitten, could become a local news story that further demonises this shy snake, causing further fear, misunderstanding and persecution.

A coiled adder in a verge.
My first ever adder spot! But I don’t know if this counts. This adder was either dead, or was playing dead (I did detect some movement, particularly from a distance as I was approaching.) However since I am not stupid I didn’t bother to prod it to check! (Credit: Me)

I feel honoured after such a long search – we’re talking hundreds of miles of treading the trails! – to have finally had this experience with an adder. They are, in the UK, a symbol of true wildness. Despite their status as a protected species we sadly continue to see their numbers decline. The release of non-native game birds like pheasant, on top of continued habitat loss and human encroachment into their territories means adders are in a perilous position. It would be a terrible shame to lose such a charming, timid predator.

It should come as no surprise I love reptiles! But snakes hold a particular fascination for me. I am a multi-disciplinary sort and the mythology and folklore of animals is profoundly meaningful. A lot of my ‘Top Ten Hated (But Misunderstood) Animals’ list looked at these myths, mostly bad!

Snakes have been a symbol that has permeated human culture since its inception. Whether as symbols of power, regeneration, wisdom or fear, they are deeply meaningful to us. They are significant to us. It would be a shame for that symbolism to pass solely into mythology, for future generations of people to never have the opportunity of seeing that symbol in the flesh and understanding it as a real, living organism.

A black and white etching of a serpent on a crucifix.
The ‘Serpent on a Cross’ or ‘Crucified Serpent’ is a powerful symbol in alchemy. It shares common themes with serpent imagery going back a long way but specifically likely stems from John 3:14 “And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up” Relating to the crucifixion of Christ. (Credit: Public Domain)

On a personal note snakes are often seen as a symbol of transformation and rebirth. This is often attributed to their skin-shedding behaviour, the casting off of an old self to replace it with a new. This symbolism carries through to the Caduceus, a staff with two snakes coiled around it with powerful transformational qualities. It is most famous as the staff of the Roman messenger god Mercury (or Greek Hermes), although the symbol itself is likely much older, potentially Sumerian in origin, thus dating back to around 3,000-2,000 BCE!  

I am currently in a period of transformation myself, funnily enough with Mercury somewhat related! Finding two snakes on the day I did…I may be reading far too much into it but whether a genuine message from the gods or simply my own mind using the world around it to make sense of what is happening to me, it brought me great comfort and peace.

To me the sights and sounds of nature can be just as powerful, evocative, informative, and memory forming as scents, music or art. The natural world is constantly changing and communicating with us and even if those messages are mere interpretations of our own internal world with no external agency to them, that shouldn’t diminish their power. How we interpret the stimuli we receive from the world around us informs us of our behaviours and emotions whether we want it to or not. I find it’s much better to consider it as much, and as consciously, as possible to ensure you’re taking home the right message.

A marble statue of Hermes/Mercury clutching a bronze caduceus.
A statue of Mercury/Hermes clutching the Caduceus. This is a Roman copy of a Greek original from the Villa of Hadrian, Tivoli. (Credit: sailko by GFDL)

For example if you see a snake and feel fear it is possibly a good idea to ask what it is you fear? Is it the snake itself? Or what the snake represents? Do you fear the adder, the timid creature who would likely sooner slither away and avoid conflict? Do you fear the reputation of the adder, built over decades of humans closing themselves off from the realities of the natural world? Or do you fear the harm, of being poisoned, envenomated, with the snake merely being the messenger of that fear of harm?

When I saw the adder I did not feel fear. I felt joy. I was so happy to finally get a good look at one of these wonderful snakes. But that joy fed into wider consideration of where my life is and where it may be going. The snake slithered as a symbol into my synapses and helped me figure out my feelings about who I am and the journey I am undertaking. The path that I am on, whether it goes well or terribly is now my snake-era! Ushered in by one of the finest sights you can hope to see in UK wildlife – The beautiful adder.

Read about some of the UK’s other fascinating reptiles:

The Common Lizard (Zootoca vivipara)
The Slow Worm (Anguis fragilis)


Published by Karl Anthony Mercer

Karl Anthony Mercer is a writer, poet, author, musician and part-time dandy. He can often be found squatting in fields looking at insects (he is an unapologetic wasp fanatic), wandering around museums over-dressed, or hiding in a dank corner singing sad songs on a small guitar. His writing on WordPress consists of MercersPoems - an outlet for his poetry often using natural imagery, gothicism and decadence to explore the struggles of living as an autistic person; and We Lack Discipline - Where he writes about factual, often academic topics he has learned and is interested in (e.g. biology, psychology, Roman history etc.) with an inimitable, often light-hearted and irreverant style. You can support Karl by; Subscribing to the We Lack Discipline Patreon - Or buying him a coffee (he loves coffee!) -

One thought on “The Adder (Or European viper) – Vipera berus

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: