The Circus Cyaneus, more commonly known as the Hen Harrier is a large bird with long wings and a long tail. The grey male has a large white rump, dark trailing edges to the wing and black wing tips, usually weighing 300 – 400g. The female, often
nick-named ‘Ringtail’, is dark brown above and paler below and also has a large white rump, usually weighing 400 – 600g.
It is a moorland bird of northern Europe and north America, with a maximum lifespan of 16 years. Feeding mainly on birds and mammals taken in surprise attack as it quarters the ground, eg small birds, grouse chicks, rodents, young rabbits and hares.It has long, slender, slightly angled wings and a long tail. It flies gracefully with a few wing beats then a long, shallow glide.
Hen Harriers nest on the ground in heather. Their nests are lined with
rushes and grasses.
They usually have 4-5, bluish-white eggs, occasionally with reddish marks on them, around May and June.
In the nesting area, their call is rapid chattering,”ke ke ke ke”. The young fledge from the end of June.
They can nest in quite high densities, have overlapping ranges and are not really territorial.
Click play to view a movie clip of Hen Harrier chicks. The movie clip may take a few seconds to download.
Many Hen Harriers breed on heather moorland and come into conflict with
shooting interests because grouse chicks can form part of their diet.
Whether they cause any reduction in the numbers available for shooting is a matter for debate, though certainly where grouse numbers are healthy, scientists have shown Hen Harriers have little or no effect on the grouse population.
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History
The Hen Harrier was once a widespread species. But research has shown
that this was changing by the late 18th century. The agricultural revolution, occurring especially in the lowlands, meant increased drainage of land, enclosures and new methods of crop growing.
During the 19th century there was a marked decrease in the number of Hen Harriers. This was thought to be mainly due to the marked rise in gamebird shooting and the associated creation of sporting estates, including enormous areas of heather moorland favoured buy both red grouse and Hen Harriers. Birds of prey were thought of by some as “vermin” and were persecuted relentlessly. The Hen Harrier fared particularly badly and, by 1900, was almost extinct as a breeding bird in main land Britain. It survived in Ireland and in the UK in the Outer Hebrides, where gamekeepers were mainly interested in wildfowl and not grouse, and in Orkney, where there were virtually no large sporting estates. Much protection work and research in Orkney were carried out by George Arthur and Eddie Balfour.
After the Second World War the number started to increase and the birds spread throughout Scotland, northern England and Wales. This could have been due to lower levels of keepering as well as to its new protected status from 1954. The recolonisation was helped by planting of forestry, rich in small bird and mammal prey in the early years of tree growth and providing nesting sites for Hen Harriers free from persecution. The new plantations were only useful in the short-term, however. As the trees grew the birds moved out to open moorland and were once again the victims of illegal killing and nest destruction. More recently, in the 1980s, there was a decline in the range of the birds.
The Hen Harrier food chain
The male Hen Harrier
The female Hen Harrier
Life cycle of a Hen Harrier
Special behaviour of Hen Harriers
Skydancing
During March and April, when the hen harriers return to moorland areas to breed, the male locates suitable nest sites and tries to attract the female to one of these. He undertakes a complicated display to attract the female, corkscrewing through the air in an undulating flight. This display is known as “skydancing” and it is not known exactly why Hen Harriers perform this activity.
Food passing
While the female is sitting on the nest incubating eggs or looking after the young birds, the male will bring food to her up to four times each day. A range of food is taken, including field voles, meadow pipits, young warders, young rabbits, red grouse chicks and this will support the female as well as the young birds. The female flies up from the nest to accept the food from the male in mid-air in an amazing food pass. This helps to detract predators from the nest site.
Artemis Fowl