Hen harrier. Persecution is prime cause of disappearance, says Natural England – Could be reintroduced to new areas
Male hen harrier ready to fledge. Credit Natural England.
Grouse moors linked to persistent nesting failure in major Natural England study February 2009. Hen harriers in England continue to be persecuted and their recovery as a species hangs in the balance as a result, according to a detailed study by Natural England, part of its national Hen Harrier Recovery Project.
The report - A Future for the Hen Harrier in England? - outlines the results of hen harrier monitoring since 2002 which provides compelling evidence of illegal hen harrier persecution in England. View the full report here
Persecution Detailed monitoring work since 2002 has shown that the critically low breeding numbers and patchy distribution of the hen harrier in England is a result of persecution - both in the breeding season, and at communal roosts in the winter - especially on areas managed for red grouse or with game rearing interests. Tellingly, 6 birds fitted with transmitters disappeared, three in one small area in 2007-2008.
The statistics make stark reading:
Between 2002-2008, the comparatively tiny area of Bowland in Lancashire accounted for over two thirds of all the 127 hen harrier breeding attempts recorded by Natural England as part of its intensive monitoring programme. Throughout the rest of England, only 19 breeding attempts were recorded on grouse moors, in spite of the suitability of the habitat.
Natural England's report shows that, outside of Bowland, persecution is the reason for the systematic disruption of hen harrier breeding attempts in areas that provide extensive and very suitable habitat and would otherwise support healthy hen harrier populations.
With the exception of the Bowland Fells grouse moors nesting attempts on grouse moors elsewhere were more than twice as likely to fail In areas managed for red grouse, only 26% of nests produced fledged chicks, compared with landholdings in the Bowland Fells where 65% of nests were successful.
Of the 72 successful nests where hen harriers produced fledglings during the last seven years, 50 were in Bowland.
The persecution continues for the small number of birds that do actually fledge from successful nests. There is further compelling evidence that this persecution continues during the winter at communal roosts.
Using tracking technology, Natural England has been collecting evidence that shows many birds are simply disappearing off the map. Over a 12 month period, six birds fitted with satellite transmitters have been tracked from the Bowland Fells into parts of the North Pennines managed principally as driven grouse moors, and have not been recorded subsequently. In another incident in one confined geographical area, three signals "went dead" between 2007-2008.
Sir Martin Doughty, Chair of Natural England said: "The hen harrier has unfortunately become the emblem of man's callous disregard for the spectacular and majestic wildlife that we have in England.
"Following seven years of intensive monitoring and detailed research, the picture is unequivocal - hen harriers are being persecuted while they attempt to nest and birds are simply not returning to their breeding areas the following spring. The hen harrier should have a much wider range than it does which begs the question why its breeding success is now restricted to one regular site. The simple answer is that this magnificent bird is being persecuted to the brink of extinction as a breeding species in England.
"Natural England is now looking to improve the fortunes of this species by examining the feasibility of reintroducing hen harriers to the lowland part of its former range. We will be working with stakeholders to take this work forward in the New Year."
Hen harrier eggs hatching. Credit Natural England.
Hen Harrier Recovery Project Natural England's Hen Harrier Recovery Project monitors the remaining breeding birds in England. One of the best places to catch a glimpse of the hen harrier is in Lancashire, on the Bowland Fells, a Site of Special Scientific Interest. This is the only area in England where the hen harrier has increased as a breeding bird since the start of the Project in 2002.
Bowland's hen harriers have consolidated largely due to sympathetic gamekeepers and landowners including grouse moor owners and United Utilities plc. Management and monitoring is carried out by staff from Natural England, the Royal Society for the Protection of Birds and volunteer raptor workers.
Hen harrier facts
Current status The hen harrier breeds widely across Eurasia and North America. About 800 pairs nest in the UK and Isle of Man, with most in Scotland. The species has an unfavourable conservation status in Europe, is a red-listed UK Bird of Conservation Concern and appears on the Government's section 41 list of priority species.
The hen harrier was once a widespread and fairly common bird in Britain and there are breeding records from many English counties from the early part of the 19th century. Numbers declined as a result of changes in habitat, for example the drainage and cultivation of marshes and heathland, and because of persecution by those seeking to protect poultry or gamebirds.
By the end of the 19th century the hen harrier had been lost from mainland Britain and only a small population survived in the Hebrides and on Orkney.
After the Second World War the hen harrier started to make a comeback, probably due to a reduction in the number of active gamekeepers and a corresponding drop in the intensity of persecution.
Northern England was re-colonised in the mid-1960s and in the 1970s and 1980s up to 25 nesting attempts were made each year in Cumbria, Derbyshire, Durham, Lancashire, Northumberland and Yorkshire. It was hoped that this was just the start of a more complete recovery but this was not to be. The population did not increase further and, to the contrary, from the mid-1990s there has been a significant decline in the bird's fortunes and a marked contraction of their breeding range.
Most hen harriers arrive back on their breeding grounds in March or April and the males and to a lesser extent females soon begin to indulge in spectacular, aerobatic display flights in order to attract a female.
Aerial displays between paired birds include turning over in flight with talons outstretched, rapid, roller-coaster chases and dramatic stoops towards the ground on folded wings.
Some males are polygynous and may be paired' to as many as six different females in extreme cases. In Bowland and other parts of England this is a rare occurrence with most birds opting for a monogamous relationship.
The hen harrier has a strong association with heather moorland in England and nests are almost always sited so that the surrounding mature heather provides cover and protection.
Moorland management ensures that a range of heather ages is in place, burning is a management tool used to burn off tall degenerative vegetation to ensure fresh heather growth, a food source of red grouse.
A clutch of 4-6 eggs is laid, usually in May, and incubated only by the female for about 30 days.
The chicks spend 30-40 days in the nest and are dependent on food brought in by the adult birds until they have learnt to hunt for themselves.
The male does the majority of the hunting until the chicks are about a fortnight old; he is then helped by the female who hunts in the nest vicinity while the male hunts usually further afield, up to 7 kilometres from nest. When returning with prey the male transfers food to the female at the nest in a breathtaking display of agility known as the food-pass. This involves the female flying up from the nest and snatching the prey in mid-air with her feet, just after it has been dropped from above by the male.
Although the hen harrier takes a wide range of different prey species, the diet in the breeding season is dominated by small birds and mammals. Voles and meadow pipits are important, particularly early in the breeding season, and skylarks, gamebirds and wader chicks are also taken regularly.
A small number of hen harriers remain on the moors outside the breeding season, but most move south to spend the winter in lowland areas within England or further south on mainland Europe. Flat landscapes with wide expanses of unbroken wetland, farmland or heath are favoured as they provide ideal conditions for the bird's long foraging flights, low over the ground.
The English population is boosted in winter by variable numbers of immigrants from northern and central Europe and, in some years, the population is thought to be as high as 750 birds. Communal roosts often form and up to 20 birds may gather together to spend the night resting on the ground, concealed from potential predators within a reedbed or other rank vegetation.