Hen harriers should be one of the UK's most numerous raptors but are functionally absent from many upland areas due to illegal killing on grouse moors, with fewer than 1,000 pairs breeding annually.
Hen harrier welfare is catastrophically affected by illegal persecution that has prevented population recovery for decades. Individual birds are shot, trapped or poisoned. The brood management scheme removes eggs from nests under licence as an attempt to reduce harrier-grouse conflict while building tolerance among land managers. Critics argue this rewards persecution by legitimising interference with protected species.