Wildlife

Adder: Britain Only Venomous Snake at Risk

Adder populations have declined dramatically and the species faces extinction in some regions without urgent conservation action.

Key Facts

UK adder populations declined by 90 percent between 1960 and 2010 in some regions
Adders are the only venomous snake native to Britain
They hibernate from October to March emerging on warm days to bask
Female adders give birth to live young rather than laying eggs
Adders are important predators of lizards, voles, and other small animals

Welfare Considerations

Adders face welfare threats from habitat fragmentation that isolates populations and leads to inbreeding depression. Persecution through deliberate killing is still common due to irrational fear. Habitat management that removes heathland, rough grassland, and sunny woodland edges eliminates essential basking sites. Predation by pheasants released on shooting estates is significant in some areas.

What You Can Do

Leave adders alone if encountered and educate others that bites are very rare
Support Amphibian and Reptile Conservation adder conservation projects
Report suspected persecution of adders to police wildlife officers
Maintain and create south-facing banks and sunny clearings as basking habitat
Advocate for reduced pheasant releasing near known adder populations