Written by Charles Bonnett, Transforming Lives Trainee.
The common European adder (Vipera berus) is one of three native species of snake found in the UK. It is unique amongst our native snakes in it’s ability to produce venom, contributing to their undeserved dangerous reputation. Beyond this reputation, they are notable for their distinct physical characteristics, unique population distributions, and place in folklore and mythology.
Physical Characteristics
Adders are small but stocky, growing up to a length of 60-80cm. They can be found in several colourations, varying from silver-grey in males to brown and copper in females. Melanistic adders can also be seen rarely, in which the increased amount of black pigmentation portrays a uniform black colour. Their distinct zig-zag pattern which extends down their back is also one of their most recognisable physical traits, and can be an ideal characteristic to look out for should you catch a glimpse of what you suspect may be an adder. Keep an eye out for a reddish iris as well, as this can be a distinctive feature.
Distribution and Habitat
The adder is notable for its ability to survive in northerly habitats, where it has been recorded as far north as the Arctic Circle; amazingly, this means that no snake can be found further north than the adder. Adders prefer open habitats, such as heathland, moorland, and sea cliffs. Ideally, their wider habitat contains a diverse and sporadic vegetation structure, and comprises of transitional zones between connected habitats; this offers suitable protection from predation, access to locations suitable for basking and hibernation, and abundant prey.
Hunting Behaviour and Diet
Whilst we’re on the topic of prey, adders will eat a range of animals, but have a preference for small mammals, such as voles and mice. They will also eat small amphibians, including frogs and newts, and they may try their luck with nesting birds. In warmer weather, they adopt a more active hunting approach, whilst during colder conditions they prefer ambush-style tactics. Once they have locked onto their potential target, they immobilise and subdue it via their venom, after which they consume their victim whole. Remarkably, due to their ectothermic nature and slow digestion time, they can survive on very small quantities of food – as little as a single small mammal a month!
Adders and Humans
Adders and humans have had a long and complicated history. In English folklore, an adder on your doorstep was considered a bad omen; likewise, serpents more generally have historically been associated with deception and evil.
Our modern relationship continues to become more intricate. Adders are a protected species under Section 9 of the Wildlife and Countryside Act 1981. It is therefore illegal to injure, kill or sell this species.
Despite this, adder populations are struggling in the UK. As we discussed earlier, many people are fearful of adders – despite the fact that they very rarely attack humans and are very reserved – which unfortunately results in undue prosecution. Similarly, human activity, including infrastructure development leading to habitat loss and fragmentation, human-driven climate change, and pesticide use, have further negatively impacted adder populations.
Ultimately, adders deserve an opportunity to continue to co-exist alongside humans. Their remarkable ecology, ecological importance, and unique characteristics surely emphasise the need for continued education and conservation surrounding our amazing adders.
If you see an adder, or any other reptiles, you can record your sighting on our free Dragon Finder app, which will assist with our reptile conservation efforts.