Adder by Simon BoothAdder by Simon Booth

Vipera berus

Among reptiles the adder is a cool temperature specialist. While our other two native snake species reach the edges of their global range in Britain, all of mainland Britain falls within the global span of the adder. In Suffolk adder are mostly found on the well-drained soils of the Brecks and Sandlings Heaths.

The adder is our only venomous snake native. Their bite is used to immobilize prey which consists chiefly of small mammals such as voles, mice and shrews. Lizards can also be taken together with the odd slow worm and perhaps even weasels and moles. Amphibians such as frogs and newts and birds too have also been reported as prey items. 

Adders usually go out of their way to avoid human contact and only use their venom as a last means of defence - usually if caught or trodden on – and even that is extremely rare. Adders are protected by law against being killed or injured through human activity.

Adders are a relatively watchable reptile, particularly during spring when males spend several weeks basking, often in the same location near hibernation sites. Most are distinctively marked with a dark zigzag running down the length of the back and an inverted 'V' shape on the neck. Males are generally white or pale grey, while females are pale brown. Some can even be entirely black and can be mistaken for other species.

The major threat to adder is habitat loss and fragmentation. The adder's habitat needs are complex; areas are needed for basking, feeding and mating. Cover from predators and good hibernation sites are also critical to survival. Adder are often restricted to habitat islands - a problem for a small snake with limited migratory abilities. Inbreeding can make them genetically vulnerable to environmental change and disease so linking habitat is crucial to their conservation.

The Trust actively manages its Sandlings reserves for a wide range of species including the adder through protection, restoration and recreation of heathland. Typical of this work is the Trust's partnership with the Forestry Commission in the management of the northern part of Dunwich Forest, which is opening up the conifer blocks to encourage a more diverse plant life. This will greatly benefit the adder population. The Trust’s Living Landscape approach aims to link up prime sites which will greatly increase the area of suitable habitat.

Have you seen an adder?  The Trust is working with Suffolk Amphibian and Reptile Group to explore the use of predictive mapping techniques to help target future survey effort more effectively. Map your adder sighting.