Two so called scientists have called for studies about limiting Hen Harriers in Scotland.

The Osprey made it's own way back, the White-tailed Sea-Eagle needed help. The Hen Harrier needs our protection against these people.  Available food governs grouse numbers just as it does for Hen Harriers. Nature, given a chance, finds it's own balance.
If predation is effecting grouse numbers lets ban grouse shooting.