Adders can be variable in colour, but typically the background colour differs in males and females.
Males tend towards a grey, whitish, occasionally yellowish colour. The contrast with the black markings can make them appear almost silver.
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| Male Adder |
The females tend to be brownish with considerable variation of shade and occasional hints of red or yellow – although in the latter case always a much darker shade than the males.
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| Female adder |
Both sexes are similarly marked. Typically these markings are very pronounced and extremely easy to identify, consisting of a heavy dark zigzag pattern down the back with dark spots in rows on the flanks.
At the back of the head there is a heavy “V” or “X” shaped marking and a dark band running from behind each eye.
The young are coloured and marked much like adult females.
Although Adders are rather stocky snakes they are not very big, seldom exceeding 60 cms in length, the males being slightly shorter.
The head shape is notably different from the other British snakes being rather broad and angular with an upturned snout.
The eyes are large and tend to be reddish in colour with a vertical pupil – again a feature unique to this species in this country.
The back pattern can vary in some individuals.
With these variations there are occasional individuals that are not readily identifiable.
