The elegant hen harrier is perhaps the most iconic bird of prey in the uplands of northern England, but it is also one of the most endangered birds in Britain.
These large raptors wheel and soar above the moorland and, in late spring, perform a spectacular ‘sky dance’, exchanging tokens of their affection in mid-air to cement their bond.
Guide to hen harriers, including how to identify them, why they are so rare and where you can see them.
How to identify a hen harrier
These large (one-metre wingspan) mottled-brown (female) or light grey (male) birds of prey glide and hover over upland moors and pluck meadow pipits or voles from among the heather. Look out for their aerobatic courtship ‘sky dance’ in which birds call and wheel through the air.
Hen harrier distribution
The Forest of Bowland in rural Lancashire supports one of the largest populations of hen harriers in England.
Around five per cent of the UK’s harrier population lives on the Isle of Man. The island’s interior of sparsely populated heather-clad hills offers the ideal habitat for the harriers’ principal prey species. Head to Snaefell, Sulby or Kirk Michael to spot harriers.
Most of Scotland’s Hebridean islands support resident populations of hen harrier. Loch Gruinart on Islay, the uplands of Arran and the Isle of Ulva off Mull are promising locations to spot a harrier.
The Antrim hills and lakes of Fermanagh are home to the majority of Northern Ireland’s breeding population of hen harriers. A visit to the RSPB’s Aghatirourke Nature Reserve or Cuilcagh Mountain Park are a good bet for spring sightings.
How many hen harriers are there in the UK?
There are an estimated 600 nesting pairs of hen harrier in the UK.
History of hen harriers in Britain – the cause of their decline
In the early 1980s, there were more than 30 nesting pairs of harriers across Bowland, forming the backbone of the English harrier population. In some years, this was the only place in England where the birds nested successfully.
“According to Natural England, the bare minimum of birds we should have in Bowland is 12 or 13 pairs, and in the past, the area supported almost three times that number,” says RSPB Bowland Project Officer James Bray. “So currently we have a quarter of the population that the Government is legally obliged to nurture and protect.”
Characterised by increasingly scarce upland peat bog and unenclosed heather-clad moorland riven by steep-sided valleys, this austere landscape is an ideal habitat for voles and small upland birds such as the meadow pipit, which are the harriers’ main sources of food. But harriers will also take the chicks of grouse introduced on to the moors for shooting, bringing them into conflict with gamekeepers and making them the most persecuted bird of prey in Britain.
The steep declines witnessed in the middle of the last decade followed the disappearance of four male hen harriers from the Forest of Bowland in 2015. While the female is on the nest, the males do most of the hunting, making them more vulnerable to persecution because they are very obvious in the landscape while hunting food to feed their chicks.
There are other factors at play, too. Heavy spring rainfall can have a huge impact on nesting success, as can fluctuations in the vole population; every so often vole numbers crash, making it difficult for the birds to find enough to eat.
Conservation of hen harriers
In 2015, hen harriers nesting in the Forest of Bowland failed to raise a single chick. The same thing happened the following year. This raised serious concerns about the viability of the Forest of Bowland’s breeding population of harriers – a doubly tragic outcome as this beautiful bird is the symbol of the Forest of Bowland AONB.
But since then, thanks to the concerted efforts of the AONB, the RSPB, conservation volunteers and one of the largest landowners in the area, the hen harrier has enjoyed greater breeding success, with 13 chicks successfully fledging in 2018 and 22 chicks in 2019.
For the moment, Bowland’s fragile population of hen harriers looks a little more secure, but the combination of habitat loss, climate change and persecution means the threat remains.
To help the Bowland harrier population recover, in 2018 as part of the Hen Harrier LIFE project, the RSPB deployed six paid staff, supplemented by a dedicated team of 15–20 volunteers who put in just over 2,000 hours between April and the end of August.
The three successful nests in 2018 were all on land owned by United Utilities, which has invested millions of pounds in carefully managing the fragile upland habitat to improve water quality, with beneficial spin-offs for wildlife.
“We’ve had a couple of really positive years and the Bowland population of hen harriers is looking slightly healthier,” says Forest of Bowland AONB manager Elliott Lorimer. “But another couple of bad years like 2015 could have a catastrophic impact on the local population. We are still a long way from being able to describe the future of the hen harrier in Bowland as secure.
“Sadly, raptor persecution continues to suppress hen harrier populations within the UK. The AONB Partnership is currently planning work with local police forces, as part of Operation Owl, to help raise awareness of this issue within local communities in Bowland and further afield within the counties of Lancashire and North Yorkshire.”
Bray adds: “It’s brilliant that we had three successful pairs this year, but it’s way too early for us to say with any confidence that this is the start of a recovery. We need several successive years of birds nesting successfully before we can say things are working as they should.”
One of the best ways to secure the continuing recovery of this seriously endangered species is to have more feet on the ground and eyes on the skies in the remote valleys of the Forest of Bowland, which is one of the most beautiful places in Britain to enjoy a spring walk.
RSPB Birdwatcher’s Code
• Avoid going too close to birds or disturbing their habitats – if a bird flies away or makes repeated alarm calls, you’re too close. And if it leaves, you won’t get a good view.
• Stay on roads/paths where they exist and avoid disturbing habitats used by birds.
• Think about your fieldcraft. Disturbance is not just about going too close – a flock of birds on the foreshore can be disturbed from a mile away if you stand on the seawall.
• Playing a recording of calls to encourage a bird to respond can divert a territorial bird from other important duties. Never use birdsong to attract a species during breeding season.