UK Hen Harrier population plummets to new low

Britain's Hen Harrier population has suffered a decline of 88 pairs — equivalent to 13 per cent — over the past six years, with the total population estimated to be 545 pairs.

The figures come from the fifth national Hen Harrier survey, which found that Scotland remains the stronghold for the species with an estimated 460 pairs in 2016, around 80 per cent of the UK population. This estimate is 9 per cent below the best estimate in 2010 (505 pairs). The west Highlands continue to host the majority of Scotland's breeding harriers (an estimated 175 breeding pairs), while Orkney and the Hebrides were the only areas of the country to show a slight increase in numbers.

The survey also revealed that Hen Harrier remains on the brink of extirpation as a breeding species in England as the population fell from 12 pairs in 2010 to just four pairs last year. Estimates from the Joint Nature Conservation Committee (JNCC) suggest there is potential habitat to support at least 300 pairs in England, highlighting the desperate situation the species faces.

The Hen Harrier population had been slowly recovering in Wales since the species recolonised in the late 1950s but the latest figures show that the number of pairs has fallen by more than a third over the past six years, from 57 to 35. This is the lowest population total in Wales for over a decade. With 46 pairs, Northern Ireland also experienced a decline in pairs after 59 were recorded in the previous survey. Hen Harriers were also surveyed on the Isle of Man, in partnership with Manx BirdLife, with numbers remaining stable at 30 pairs, up one on the 2010 total.

Longer-term figures highlight the dramatic decline the UK population has suffered over the past 12 years. The national survey in 2004 pointed to an estimated 749 pairs, meaning Hen Harrier numbers have fallen by 204 pairs (39 per cent) since then.

Known for their majestic 'skydancing' ritual, Hen Harrier remains one of the most threatened birds of prey in the UK. Historically the species was once a much more widespread breeder before it was driven to extinction in mainland Britain during the 19th century. Despite its comeback, the species has remained rare in the UK and continues to prove vulnerable to the effects of habitat loss, weather and illegal killing.

The UK population of Hen Harrier has declined by 39 per cent since 2004 (Photo: Derek Bilton)

Martin Harper, RSPB Conservation Director, said: "Hen Harrier is one of our most wonderful birds of prey, to see one soaring through the air before dramatically diving down during its thrilling skydancing display is an iconic sight and one that will always take your breath away. These are sights that we should all be able to enjoy. Unfortunately, we are being robbed of the chance to see these beautiful birds flourish throughout the UK countryside."

The reasons for the population changes are likely to be a combination of factors that vary from region to region. From previous research, it is known that the main factor limiting the UK Hen Harrier population is illegal killing of these birds associated with driven grouse moor management in northern England and parts of mainland Scotland. Other pressures such as cold and wet weather conditions over a number of breeding seasons, changes in habitat management and low prey abundance could have all had an impact on numbers throughout the UK.

Martin Harper added: "The latest figures back up a continued trend that we have seen for more than a decade — Hen Harrier numbers are on the decline throughout the UK. The illegal killing of this bird of prey is a significant factor behind the diminishing numbers and a large barrier stopping their recovery. Without purposeful action from all, including governments across the UK and the shooting industry, we may see Hen Harriers once again lost from more parts of the country."