Water voles (Arvicola amphibius) are Britain's fastest declining native mammal, with American mink predation and habitat loss driving populations to the brink of local extinction.
Water vole welfare is inseparable from predation pressure: populations under active mink predation experience high mortality rates, chronic stress from predator presence, and ultimately local extinction. Individual vole welfare during mink predation is acutely compromised. The welfare argument for mink control is therefore that it prevents massive ongoing welfare harm to water voles. Mink trapping and euthanasia itself involves welfare considerations: humane trapping protocols require trap checking at least every 24 hours to prevent prolonged capture stress; euthanasia must be immediate and humane. The two welfare calculations — harm to individual mink from trapping versus harm to water vole populations from mink predation — are both legitimate considerations. Wildlife conservation organisations generally conclude the balance strongly favours mink control for water vole recovery.