The hen harrier is one of the UK's most persecuted raptors, with illegal killing on driven grouse moors causing chronic population suppression and significant welfare harm to individuals.
Hen harrier persecution causes violent and painful deaths to protected birds and destroys nests containing eggs and chicks. Individuals who survive persecution attempts but are injured face slow deaths from untreated wounds. The cumulative effect of persecution has compressed the English breeding population to functional extinction in its core habitat. Camera trap evidence and satellite tracking data have documented numerous cases of illegal killing, yet prosecutions remain rare. Ending illegal persecution is the single most impactful welfare intervention available for this species.