'Thug' owls escape Government curbs

Concerns had been raised that the enormous owl, which is not normally found in the UK, has had affected other species, in particular the rare hen harrier in its last remaining stronghold in England.

The wild eagle owls, which can be up to 30 inches tall and have wingspans as big as 5ft 6in are thought to have escaped from captivity. About 3,000 are kept in the UK.

Earlier this year, an eagle owl was photographed attacking a female hen harrier sitting on eggs in Bowland, Lancashire, and the brood failed to hatch.

Only seven of the much-persecuted hen harriers successfully nested in England this year

In their natural habitat, eagle owls may kill other predators, either for food or to remove competition, and reduce the breeding success of other birds of prey.