Читать книгу Bowland Beth: The Life of an English Hen Harrier - David Cobham - Страница 10

There was no sun and the moor was white with frost when, two days later, the male hen harrier drifted down to Mallowdale Pike ridge in search of a mate. He passed up and down a couple of times, and on the last flypast noticed a female hen harrier in the tall heather tearing at the tussocks of dead grasses below, throwing them in the air. Cautiously he planed down and landed close by. She was larger than him, and in the first glimmer of sunshine he admired her glossy chocolate-brown plumage, noticing the white wing tag with the number 22 in black. He walked over to her. She looked at him and he could feel her sizing him up. Was he good enough? He’d show her.

He rocketed up into the sky. The female watched as his blue-grey outline melded into the now blue sky above. At three hundred feet he turned and plunged into a vertical dive towards her. In freefall he corkscrewed and screamed to attract her attention. Faster and faster he fell. Then, just when it seemed that he would crash right into her, he pulled out and soared up in the air again. He was reckless in his efforts to impress her. Three times he repeated the death-defying plunge earthwards before finally landing by her side. He was panting, plumes of breath hanging in the frosty air. She was impressed and sidled over to crouch submissively by his side. He had found a mate.

‘My routine when I’m checking for the harriers’ arrival,’ says Stephen Murphy, ‘is to drive round to the north side of the central mass of the Forest of Bowland. Here it is split by a valley, and where the harriers nest is way back beyond the horizon. I’ll park my car and watch. This is a muster point for hen harriers looking for a mate. In March and April I have seen eight birds there, all “skydancing”. It’s like a big aerial dance floor, a real sight to behold. When they’ve found a mate, they’ll fly up the valley and up out of sight to where they’ll find a nest site.

‘A week or so later I’ll walk up onto the fell and find myself a spot in the heather where I can scan the distant hillside through my binoculars. At the moment I’m checking one of the traditional harrier nesting sites way across the valley. It’s a favourite site – they’ve always produced young from there. We’re in the last couple of weeks of March and any pairs of hen harriers should be arriving any day now.’

It is the female that makes the choice of where the nest will be, and shortly afterwards she can be spotted flying in carrying grasses or large sprigs of heather or bilberry in her beak, a sure sign that nest-building has started. Starting from scratch, the female chooses a bare area for the nest in tall heather but with easy access to it from one direction. Generally, all the nesting material – from quite bulky twigs to smaller sprays – is picked up within two hundred metres of the nest.

Flying out from her chosen site she pitched on an old heather burn and meticulously pulled up lengths of dead heather with her talons, then flew to the nest site. Here she started intertwining them. Off she went again, and each time she returned she methodically knitted the heather strands together, gradually building up the finished nest. She stamped around in it to perfect its saucer shape, then lined it with grasses and, as a final touch, added some bilberry leaves. As she did so her white wing tag with the number 22 in black came into view. She noticed that she was losing feathers on either side of her breast-bone and that the bare areas were becoming suffused with blood – these were her brood patches.

Three other pairs of hen harriers had arrived on Mallowdale Pike, and were busy skydancing and searching for nest sites, making it a communal nest site.

Stephen Murphy lowers his binoculars. ‘I remember helping my friend David Souter wing-tag that bird last year,’ he said. ‘This was the area from which she fledged. She’s obviously decided it’s where she’s going to nest.

‘I always keep well back from a potential nest site, at least 500 metres. With a good pair of binoculars you can be pretty sure of what’s happening, and it all goes in my diary – weather, behaviour and so on.’

Their nest complete, the pair were ready for the next stage of their courtship, the magic of copulation. Seizing the moment, the cock bird flew in with a vole he had just caught. The female rose up from her nest and caught it as her mate passed it to her, and then they both landed. The female called to the cock bird, which approached her in a frenzy of excitement and mounted her. She moved her tail to one side, and he manoeuvred so that their engorged sexual organs came into contact. He flapped his wings to keep in position, there was a brief shudder and it was all over.

For the next week or so the pair of harriers copulated several times a day, before his mate became moody and disinterested and took to the nest she had built, these last acts of copulation having stimulated a daily release of eggs from the ovary. It was now the middle of April. Nearby a hen stonechat had built her nest of moss and grasses at the bottom of a thick stand of heather that was just starting to sprout some green shoots; she was incubating five speckled brown eggs. Her mate was perched on the top of a branch of heather, asserting his right to the patch by constantly spreading his tail and flicking his wings.

On the fifth night the female hen harrier became restless, shifting uneasily in the nest. Finally, at four o’clock in the morning she stood up, legs well apart, arched her back and laid an egg. It was pale blue. She peered at it, touched it with her beak and then settled down over it. At first light the cock bird dropped into the nest and offered her a meadow pipit. She shuffled off the nest to eat it. Her talons grasped the pipit, her beak tore it apart and she gulped it down, allowing her mate a moment to proudly inspect the newly laid egg.

Roughly every forty-eight hours she laid another egg, until she had a full clutch of six. A day or two after laying, the pale blue colour of the eggs changed to a chalky white. The inflamed bare areas on her breast were now hot to the touch and, with the arrival of the second egg, she started incubating. When she left the nest it was only to fly around for ten minutes or so before her hormones pulled her back to her treasured clutch of eggs. The cock bird was very attentive, bringing her food to the nest and roosting nearby at night. Incubation was a long process, and it would be another three and a half weeks before the first egg would hatch.

Suddenly, the female heard the cock bird calling. She took off and flew up to meet her mate, who was flying towards her. He was carrying a meadow pipit, and he slowed down to enable the female to turn and trail below him. He dropped his prey and the female flipped over in the air and caught it.

Stephen Murphy crouches in the heather, watching. ‘After the food pass the female flew to a boulder to eat the prey item before returning to her nest, a definite confirmation of where the nest is. I don’t want you to think that I’m working alone all the time. I’m fortunate to have the back-up of RSPB watchers who are employed on a summer season-only basis and I’m also able to call on local keen bird watchers whom I trust. We share any information we gather.

‘In 1975, when there was only one pair of hen harriers nesting at Bowland, the two Bills – Bill Hesketh and Bill Murphy – mounted a twenty-four hour watch on the nest site to ensure that the young were reared successfully. In fact, in 2011 it was the two Bills who found the nest that produced Bowland Beth.’

‘It was 6 April,’ says Bill Hesketh, ‘a glorious morning on my watch as we settled down among the heather in the shadow of a peat bank. The whole of wild Bowland proper laid out in front of us – just heather, bilberry, rush and sky. At 10.45 am, quite a distance away, a female hen harrier came floating down from Mallowdale Pike. Her right wing had a tag on it, white except for a narrow pink band at the base – no tag could be seen on the other wing. Over the next fifteen minutes she began criss-crossing last year’s nest location at a low height, at intervals setting herself down on the same spot.’