6 minute read
Return of the marsh harrier
MARSH HARRIER: MIKALAY VARABY NATUREPL.COM Marsh harriers are the biggest of our harrier species, with a 1.3m wingspan.
the HauntingMarshes
Ben McFarland
is Head of Conservation for Suffolk Wildlife Trust.
The majestic marsh harrier is one of the UK’s untold conservation success stories, and it has Suffolk at its heart. BY BEN MCFARLAND
As a young conservationist living in Oxford, I used to drink in the Marsh Harrier pub. Found in a slightly grittier part of the city and despite serving one of the best pints around (Brakspear, if you were wondering), it was considerably less famous than some of the other pubs frequented by Tolkien and others in years gone by. A bit like its namesake pub, the marsh harrier strikes me as being rather overlooked compared to some other birds of prey.
The dance of the marsh harrier is captivating. Rising into the air, the male turns swiftly before plunging and tumbling at speed. The female rises and in a moment of pure wildlife theatre, she locks talons with the male, spinning as they fall. It is one of the most exhilarating sights in nature.
Often mistaken at distance for a buzzard, marsh harriers lack the glamour of larger raptors like golden eagles. It doesn’t have the Terminator-like fascination of the goshawk or the media driven coverage of the sadly beleaguered hen harrier. It’s never been swept into public consciousness by famous and successful reintroductions like the red kite. Yet the marsh harrier is a beautiful bird and one of the true conservation successes of recent decades. It’s a story of decline followed by a meteoric rise, and only now are we beginning to see the extent of its success.
Understated beauty
They are the largest of the harriers, heavier than the hen harrier with a wingspan of up to 130cm. Typical of many raptors, the female is larger; she can weigh up to 800g compared to 650g for a male. Buzzards are much heavier, with the largest females occasionally reaching 1300g. The sexes display classic dimorphic plumage; the males have a brown body, lighter tail with black tips
on greyish/brown wings. The females are darker with a distinct cream head and dark eye stripe.
Most experts consider the Western (or Eurasian) marsh harrier Circus aeruginosus is one of six marsh harrier species found worldwide; those breeding in the UK are one of two sub-species, the other a North African resident. Across Eastern Europe and Asia, some eastern birds winter in the Indian subcontinent whilst others prefer Africa, from Senegal and The Gambia across to Tanzania. In the UK they are generally resident, although some winter along the south coast and they are a summer visitor to the Highlands of Scotland.
They are an ambush predator, flying low over reeds and scrub. Their long legs are brilliant at snatching prey from the ground and shallow water, including coot, moorhen, frogs and toads, small fish and even insects. As such, they are a good indicator of healthy wetland habitat.
Fall and rise
The Marsh Harrier, written by the late Dr Roger Clarke, describes their grisly decline. At the beginning of the 1900s marsh harriers were hunted to extinction, driven by a cultural tradition to eliminate anything with curved beak and hooked claw. After 1911 they made a cautious return starting in Norfolk, until in the 1950s and 1960s, they were struck by the menace of the pesticide DDT. Eloquently described in Rachel Carson’s landmark book Silent Spring, DDT accumulated in the body and eggs of birds of prey. So rapid was the decline of the marsh harrier that by 1971 there was only a single pair in the country, at RSPB Minsmere, here in Suffolk.
Since then, there has been a sustained gradual recovery. DDT was mercifully banned. Protection came under the Wildlife and Countryside Act in 1981 and whilst not halting persecution entirely, helped reduce it significantly. Importantly, this gave the species an opportunity to bounce back. Thanks to the ongoing work of conservation organisations like Suffolk Wildlife Trust, RSPB and Natural England, management of key reedbed sites helped the marsh harrier recolonise much of Suffolk.
Suffolk success
Marsh harrier colonisation of our reserves over recent years has been remarkable. Through hard work we have created ideal reedbed habitat and their response has been amazing. Perhaps most striking has been their spread from traditional coastal strongholds to reserves further inland. Providing this space is critical to their long-term survival in the face of threats such as
FLEDGLING SUCCESS
Between 2015 and 2021, numbers of marsh harriers fledging from Lackford Lakes, Carlton Marshes and Redgrave & Lopham Fen have climbed from two to 15.
Marsh harriers were hunted to extinction and then badly impacted by pesticides like DDT.
Marsh harriers are one of the species at stake due to the proposed development at Sizewell C.
Sizewell C and coastal change. At Lackford Lakes near Bury St Edmunds, they first colonised as recently as last year when they successfully fledged two chicks. At Redgrave & Lopham Fen, they started breeding in 2015 and this year was their best season so far, with five young fledged.
The marsh harrier is no average bird, nor even an average bird of prey. A bit like my Oxford pub, it’s an undiscovered gem: unlike the pub, this one can be found in Suffolk. Marsh harriers are ambush predators, diving on to prey from above.
Where to see marsh harriers
suffolkwildlifetrust.org/ nature-reserves
SIZEWELL C: MARSH HARRIERS AT STAKE
For many years, EDF (the developer of the proposed nuclear power station next to Sizewell Belts SSSI and RSPB Minsmere), took some convincing that the breeding marsh harriers at Minsmere used the SSSI, managed by Suffolk Wildlife Trust, for regular feeding. Then one day, on a site visit to the reserve with RSPB, Natural England and EDF, a majestic female marsh harrier flew over Goose Hills before descending to the marshes to forage. Since then, we’ve worked closely with EDF and RSPB to get the proper compensation in place and EDF now accept that the development will block the route of marsh harrier to feed in the SSSI.
In the UK, marsh harrier are strongly associated with phragmites reedbed and wetlands, whereas EDF’s current proposals largely revolve around the creation of dry habitat. Although closer to the Minsmere reedbed than the lost area of SSSI, there remains a huge doubt whether this will compensate for the loss. We will continue to work with EDF to monitor the compensation areas to find solutions if an overall impact does occur.
Find out what we're
doing suffolkwildlife trust.org
