Adder Vipera berus

Adders are relatively small, stocky snakes which prefer woodland, heathland and moorland habitat. They are grey or reddish brown, with a darker and very distinct zig-zag pattern down their backs. Rarer black forms are also sometimes spotted.


Adders hibernate from October, emerging in the first warm days of March, which is the easiest time of year to find them basking on a log or under a warm rock.

They hunt lizards and small mammals, as well as ground-nesting birds such as skylark and meadow pipit.


  • Length: 65cm
  • Weight: 50-180g
  • Average lifespan: 8-10 years


Protected in the UK under the Wildlife and Countryside Act 1981 and classified as a Priority Species in the UK Biodiversity Action Plan.


Widespread across the Scottish mainland, but not found on many of the Scottish islands.

When to see

March – October


  • The adder is Britain’s only venomous snake, but its poison is generally of little danger to humans: an adder bite can be very painful and cause a nasty inflammation, but despite stories is really only dangerous to the very young, ill or old.
  • Adders are secretive animals that prefer to slither off into the undergrowth than confront and bite humans and domestic animals; most attacks happen when they are trodden on or picked up. Instead, they use their venom to immobilise and kill their prey of small mammals, nestlings and lizards.

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Common name


Species name

Vipera berus

IUCN Red List status

Least Concern

When to see in Scotland

March – October

Where to see in Scotland

Scottish Wildlife Trust reserves such as Carsegowan Moss, Feoch Meadows, Grey Hill Grasslands, Knowetop Lochs, LargiebaanShewalton Wood, Southwick Coast and Woodhall Dean

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