Читать книгу Bowland Beth: The Life of an English Hen Harrier - David Cobham - Страница 8

The sun was blood red as it broke the horizon and lit the communal roost where the female hen harrier had spent the night. She watched the other harriers as they left to go foraging for food out on the moor. She didn’t join them, for she had felt a quickening in her body, an urge to move to Mallowdale Pike, a rocky crag from where she had fledged nine months ago. After preening – getting her feathers into flying order – she lifted off from the roost and soared up over the fell.

Soon she was able to see the familiar mosaic pattern, the result of annual heather burning. She twitched her tail feathers on one side and completed her refamiliarisation with the grouse moor beneath her. But then she suddenly sheered away. There was something wrong. Smoke was billowing up and she could see men beating at the flames beneath her. Why were they destroying her birth place?

The first mention of the hen harrier was in 1544 by Dr William Turner in his Avium praecipuarum, the first bird book to be printed, during a comparison of his field observations with those made by Aristotle and Pliny.

The Rubetarius I think to be that Hawk which English people name Hen Harroer. Further it gets its name among our countryman, from butchering their fowls. It exceeds the Palumbarius in size and is in colour ashen. It suddenly strikes birds when sitting in the fields upon the ground, as well as fowls in towns and villages. Baulked of its prey it steals off silently, nor does it ever make a second swoop. It flies along the ground the most of all. The Subbuteo I think to be that hawk which Englishmen call Ringtail from the ring of white that reaches round the tail. In colour it is midway from fulvous to black; it is a little smaller than the Buteo, but much more active. It catches prey in the same manner as the bird above.

Turner treated both birds as if they were different species. All ashen-coloured harriers, the male birds, were known as hen harriers, while the brown ‘subbuteos’, with white around the tail, were called ringtails.

This dimorphism of the harrier was a riddle that was not solved for another three hundred years. Thomas Bewick in his History of British Birds, published in 1797, added a cautionary footnote to his description of the hen harrier: ‘It has been supposed that this and the following are male and female; but the repeated instances of hen harriers of both sexes having been seen leave it beyond all doubt that they constitute two distinct species.’ At around this time John Latham made an extremely sensible suggestion that would cut through all the hot air that had been generated – take some chicks from the nest and keep them in captivity for three or four years to confirm the change in plumage.

George Montagu now applied himself to solving the ‘harrier problem’. In 1807 he wrote a paper that stated two vital facts. The bird familiarly called a ringtail and given the scientific name pygargus was in fact the female hen harrier, cyaneus. In his meticulous way he described how he had taken a nest of three hen harrier chicks and reared them in captivity – exactly what John Latham had suggested. One died, but eventually the remaining two moulted into adult plumage, a grey male and a female – a ringtail. Having done this, George Montagu was able to properly describe them as two different species, the silver-grey male hen harrier and the smaller, more graceful, silver-grey Montagu’s harrier. The hen harrier was given the Latin name Circus cyaneus, while the Montagu’s harrier was now known as Circus pygargus. Their females, sombre brown with a conspicuous white rump, were known as ringtails.

Later that century, J. H. Gurney, not to be outdone, reared three hen harrier nestlings taken from a marsh near Ranworth decoy in Norfolk. When fully fledged, they all displayed the rich chocolate colour of their immature plumage. On moulting, two out of the three proved to be males. They survived for five years and one is now preserved in the Castle Museum in Norwich.

I was recently allowed to study four skins of female and male hen harriers and Montagu’s harriers on loan from the Castle Museum. The female hen harrier was enormous, measuring 28 inches from beak to tip of tail. Maybe it was a Scandinavian bird, which are bigger. The skin of the male Montagu’s harrier demonstrated perfectly one of the key identifying features – the primaries projected beyond the tip of the tail.

It is time now to examine the fully adult bird in more detail. The female hen harrier and the immature male are rather dull compared with the adult male. The female’s head and nape are light brown with dark streaks and the back is dark brown. The secondaries are barred and the primaries are dark. The rump is white and the tail feathers have three narrow transverse dark bars and a much broader bar at the tip. The underside is pale brown with longitudinal dark brown streaking. The female is considerably larger than the male.

By comparison the male is a spectacularly handsome bird. The beak is black and the cere yellow, bristles cover the area between the cere and the eyes, which are a clear yellow, and there is a distinct owl-like, facial ruff edged with short, very distinct feathers. The head, nape, upper back and upper wing coverts of a fully adult, five-year-old bird are silver-grey. The rump is white, contrasting with the tail feathers, which are light grey with dark transverse bars and have white tips, apart from the two central tail feathers, which are plain grey and unmarked. The first five outer primaries are black, the underside is grey, becoming lighter towards the vent, and the legs are yellow and long.