Within my local area human activity over the past few centuries has resulted in the vast majority of adder populations being lost due to habitat destruction, management of moorland for grouse hunting through burning, gamekeeper paranoia or through the fluctuations in predator populations, most notably the common buzzard (Buteo buteo). The latter has flourished in recent decades and although a delight to see commonly in the skies once more they do take a large number of adders as prey, especially when feeding their chicks and the large numbers of buzzards back in our skies is bad news for some of our fragmented adder populations up north.
However, I try hard to find areas where adders are still hanging on, sometimes they are down to the last few adult individuals. Myself, Carl and Katarína visited a population that I had not visited before and as far as I am aware they have not been monitored for several decades. Despite the usual problems faced by adders at most sites such as too many walkers nearby with dogs, being close to a road and the inevitable buzzard nest in the adjacent woodland this site was quite nice. In the end we only came across one female and the sloughs of two males but the recent hot weather could have contributed to this and there are surely more specimens there to be found.