The adder, Britain's only venomous snake, is declining across much of its range due to habitat loss and illegal killing, raising welfare and conservation concerns.
Individual adders face welfare threats from illegal killing by people who fear or dislike snakes, often through blunt force trauma or cutting, which causes severe pain before death. Habitat loss forces adders into smaller and more fragmented populations where they may face starvation due to reduced prey availability. Road mortality affects snakes crossing between fragmented habitat patches. Illegal persecution represents a direct welfare harm that the legal protection of adders is intended to prevent, but enforcement is difficult. Conservation grazing and scrub management that maintains heathland quality directly benefits adder welfare by preserving thermoregulation sites and prey populations.