Study suggests widespread illegal killing of Hen Harriers

A new study has confirmed that Hen Harriers in England suffer from abnormally high levels of mortality compared to populations in Orkney and mainland Scotland. According to the research, published in Nature Communications, the most likely cause of this is illegal killing on and around grouse moors.

The paper is the conclusion of a 10-year Natural England study involving 58 satellite-tagged Hen Harriers. The study proved the probability of Hen Harriers dying, or disappearing, was 10 times higher within areas predominantly managed as grouse moors when compared to areas not managed for shooting. As well as this, the study revealed that 72 per cent of tagged harriers were either confirmed or considered very likely to have been illegally killed.

The study found that nearly three-quarters of tagged Hen Harriers were thought to be illegally killed (Bob Garrett).

Stephen Murphy, from Natural England, led the data collection and said: "Natural England welcomes the publication of this study, which demonstrates the value of tagging as a legitimate conservation tool. These analyses are a significant step in understanding the fate of tagged Hen Harriers, and confirm what has long been suspected – that illegal persecution is having a major impact on the conservation status of this bird."

The long-term study has enabled patterns of disappearances to be assessed across a large number of birds. This provides overwhelming evidence that illegal killing is occurring on some grouse moors, where some gamekeepers view Hen Harriers as a threat to their grouse stocks. Dr Megan Murgatroyd, from the University of Cape Town, who is the lead author of the study, commented: "Natural England’s long-term commitment to this tracking study has yielded an important dataset involving over 20,000 individual fixes. This is a remarkable achievement for a species whose population in England has averaged only a handful of pairs for the last few years. 

"While dead harriers can be disposed of, the pattern of Hen Harrier disappearances revealed by this data could not be hidden. The multiple levels of analyses of the data have all led to the same robust conclusion that Hen Harriers in Britain suffer elevated levels of mortality on grouse moors, and this is most likely the result of illegal killing."

Rob Cooke, from Natural England, added: "Natural England will continue its satellite tracking work to further improve our understanding of Hen Harrier movements and behaviour, and will continue work to improve the conservation status of the species. Natural England welcomes the support of many landowners in this, and will continue to work with all landowners and other interested parties to find ways of enabling Hen Harrier populations to increase from their current critically endangered levels in England."