THE ANIMAL FILES

Adder

Vipera berus

A northern snake’s year includes a long winter pause.

The adder is a mainly ground-living snake whose activity changes with latitude and season. Winter dormancy can occupy much of the year in northern populations, while feeding includes small mammals, lizards and other locally available prey.[1]

Follow the evidence ↓
Adder
Image: Benny Trapp · Commons · CC BY 3.0
Seasonal timing
Winter dormancy length varies geographically.[1]
Ground and low cover
Low bushes and banks can also be used.[1]
Food changes with size
Young snakes take smaller prey.[1]

Seasonal timing

Winter dormancy is shorter in Britain than in northern Sweden. During mild periods, adders may emerge to bask where snow has melted. Local weather helps set the active season.[1]

Ground and low cover

Adders are predominantly terrestrial, but can climb into low bushes or onto banks to bask or search for prey. Activity is often daytime in the north, while southern populations can use evening or summer night hours.[1]

Food changes with size

Adults commonly eat small mammals and lizards, with amphibians and other prey also recorded. Young adders take small lizards, frogs and other small animals before their diet becomes more adult-like. Local availability shapes which items feature most strongly.[1]

A COMMON MIX-UP

Must an adder be active only in the daytime?

No. Activity varies geographically and seasonally and can include evenings or summer nights.[1]

TRY A LITTLE REASONING

Why might two northern populations have different lengths of active season?

Reveal the explanation

Their local winters and suitable temperatures differ, changing the period of dormancy.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Adder (cited revision)
  2. NCBI Taxonomy — Vipera berus

Last fact check:

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