The Adders are returning

As we move through spring and the days, get both longer and warmer, a fantastic group of animals start to make an appearance. Legend has followed them through the centuries imbibing them with mystery and magical powers form witchcraft and magic through to religious symbolism.

Of course, I’m talking about our amazing reptiles and amphibians. Britain has 6 species of reptile including 3 snakes (Grass Snake, Adder and Smooth Snake) and lizards (Common and Sand and the slow worm). My favourite of all these and the one which I have spent the most time observing is the Adder (Vipera berus).

The Adder is Britains only venomous snake and is easily distinguishable from all other species. They have a distinct diamond pattern along their back and an arrowhead pattern on their head. For those that get close enough (which is not advisable), they have dark red eyes with vertical pupils, unique in British snakes.


A pair of Adders mating somewhere on the Mendip Hills
A pair of Adders mating somewhere on the Mendip Hills

Adders are viviparous meaning eggs develop inside their body, giving birth to live young in the late spring. Being cold-blooded or exothermic to use its proper name means that they must warm their bodies before they can move, hunt or even digest food. They need to raise their body temperature to over 25 degrees leading to them being often observed on drystone walls and dry grass basking in the morning. It is more common to see the larger females basking as they need the warmth to develop their young inside them. Some years they may not have their first meal until May having not eaten since the previous September.


Sadly, the Adder is in massive decline with 90% of known site having a small population of 10 or fewer adults. This is due to several causes from climate change through to habitat destruction. Interestingly, adults will return to the same hibernation spot every year.

If you are lucky, you will see the adder dance of upright entwined snakes. Once thought to be a mating ritual, it is now known that this is just two or more males fighting over a lone female who may or may not be nearby.