an artical from bbc - 达人(昕昕)

2005/10/27 | an artical from bbc
类别(冷藏的宝库) | 评论(4) | 阅读(37) | 发表于 15:43: February, the beginning of the breeding season, is a great time to watch white-tailed sea eagles. I remember watching from cliffs on the Isle of Skye, one icy February, a pair of sea eagles circling effortlessly on massive wings half a mile away. As they turned, the sun caught the brilliance of their white tails and bright yellow bills. But when I was young, Skye was devoid of the birds.

Long ago, sea eagles were found throughout the British Isles, mainly around the coasts and near marshes and large lakes. Then from the Middle Ages they were persecuted, deprived of habitat and pushed to the margins. The final onslaught was in Victorian times, when they were pushed to extinction in Scotland by sheep farmers and sporting estates, and finally by plumage and egg collectors. The last recorded nesting pair was in Skye in 1916, and the last single bird was shot in Shetland two years later.

On the up
Now, not only are white-tailed sea eagles back, life is getting better for them. Last summer in the Highlands and Islands, the eagles reared 26 young, doubling the previous record set in 1998. And it's likely that, with adults, sub-adults and last year's young, the Scottish population may now total about 150.

And of those, up to 35 pairs are starting a new breeding season. The males will be bringing prey to the massive eyries for their mates, and early mornings will be enlivened by their yelping duets. Sometimes the birds stand side by side and throw their large banana-yellow bills skyward to utter their calls, while at other times they call as they soar in tandem, holding their nine-foot wingspans a few yards apart. Soon, there could be as many as 40 pairs, which hasn't happened in Britain since the eighteenth century.

Landmarks
Those of us fortunate enough to have been part of the Sea Eagle Project live by such landmarks - the first breeding pair in 1983, the first chick in 1985, the tenth pair in 1994, the hundredth chick in 2000 and the first wild-born chicks to breed - all markers of success on a long journey that started with a few birds from Norway in 1959 and 1968 and was brought to first success by the Nature Conservancy's 10 years of hard work on Rum from 1975.

From Rum, the young eagles spread up and down the west coast and out to the Hebrides. Some of those original colonists, survivors from the 82 young brought from Norway between 1975 and 1985, are still breeding. A further import and release of 58 young in Wester Ross from 1993 to 1998 secured the population.

Up and away
As the years have gone by, our knowledge of sea eagles has increased, but our enjoyment of these beautiful birds has never diminished. To me, it has been particularly special to see a lost species integrating itself again in its ancestral haunts.

My first memories are of Fair Isle and the day the young sea eagles arrived after being flown from Bergen. It was the first flights I remember best: the huge young eagles lumbered into the skies to the panic of the gulls and ravens, whose kind had not seen a sea eagle in 100 years. On Fair Isle last autumn, I was talking with my old friend George Stout, and it hardly seemed like 35 years ago that I'd met him outside his croft the day after the first release. He'd just seen a sea eagle in flight and remarked, "It's like a flying barn door," a comment that has since found its way into the identification guidebooks.

In the eastern Highlands, where I live, sea eagles are regular visitors in autumn and winter. One of their favourite foods is dead and dying salmon in the headwaters of big rivers such as the Findhorn, Spey and Dee. After spawning, some of the fish die in the shallow waters and wash up on the gravels, where great black-backed gulls and ravens traditionally scavenge them. Now they are pushed aside by the bigger competitor. Then the eagles stay on through the winter to feed on the grallochs, or stomachs, of red deer culled by stalkers.

Pride of place
There's still some animosity towards sea eagles, and sadly, some are still illegally killed. As carrion-eaters, sea eagles will eat dead lambs in spring, and a few individuals on Mull have killed lambs. But most people are proud of the birds and in rural areas recognise they are good for tourism.

Without persecution, sea eagles have got more used to people and are much less shy than golden eagles. In several places, fishermen have started throwing fish to them. Some eagles will come within metres of a boat and the encounters set cameras clicking.

We are already wondering what sort of summer it will be, how many pairs will breed and how many young will be reared. Will we reach 40 pairs, and will the record of young be broken? What we do know is that new steps will be taken on the birds' long journey of recovery. They will give great enjoyment to people seeing a sea eagle for the first time in the wild and bring more wonderful memories to those of us who have followed them since they were first reintroduced to Scotland.

Where to watch sea eagles in Scotland
More and more people are enjoying sea eagles in Scotland as it changes from a rare and elusive bird to a star attraction. Locations used to be kept secret, but now the great bird appears on tourist brochures, at public hides and on closed-circuit nest television.

At the moment, there are no feeding locations, as there are for red kites, but that's just a matter of time.

To watch sea eagles, you still need planning, time, good weather and luck. Sea eagles are rather lazy birds and will sit for hours before hunting or flying. Though there's no need to get up at the crack of dawn, large raptors are often more active in the morning.

Find a place in sea eagle country with a broad vista and wait for at least a couple of hours. Take a picnic. Keep checking the horizon with binoculars and look for noisy mobbing behaviour by buzzards, gulls, crows or ravens. Scan rocky knolls on hillsides and big rocks along the shore. You may even be lucky enough to see one trying to steal a fish from the local otters.

The best places to look for sea eagles in Scotland are the islands of Mull and Skye. Mull has a public-viewing hide run by the Forestry Commission, the RSPB, Scottish Natural Heritage and the Mull and Iona Community Enterprise. Depending on where and if they breed, there are CCTV pictures of the nest and opportunities to see the parents flying in the area. There are also many other places on Mull where you can try to find the birds on your own or with professional guides.

On the Isle of Skye, the Aros visitor centre near Portree has a section devoted to sea eagles. If the local pair is successful, there are live pictures from an active nest and tips on where to go to see the birds, but it isn't possible to see them from the centre.

Nowadays you can find sea eagles throughout the West Highlands, from Oban north to Ullapool, and throughout the Western Isles. Wandering birds can be seen eastwards to Aberdeenshire and the Moray Firth. For information, check with tourist organisations and RSPB area offices.

The Mull and Iona Community Trust is a useful source for sea eagles on Mull. Or just ask the people running your self-catering cottage, hotel or B&B; if they don't know, they'll know someone who does.

Remember the welfare of the bird, and don't go near nesting eagles. It can be damaging to them and is illegal.

Resurgence in Europe
There are now about 5,000 pairs in Europe, with the main populations in Norway (2,000 pairs), Poland (500), European Russia (500), Germany (360), Sweden (310) and Finland (240). Mostly this is seen as an excellent situation, even though there's still some illegal poisoning, contamination from lead bullets in carrion and accidental deaths on such things as power lines and wind generators.

But the sea eagle is still missing from the southern half of the continent. As late as the 1950s, the last ones died out on Corsica. Once, the birds bred throughout the Mediterranean and on the African coast, with large populations in Iberia, France and the British Isles and from the Low Countries through to Italy and Greece. Long-term persecution and habitat destruction caused massive extinctions. Now people in southern Europe have forgotten they belong there.

White-tailed sea eagles have a slow rate of spread. So it could take decades for them to move naturally to new areas, and centuries to reclaim their original range. Occasionally, they may take bigger steps, but there is no doubt that reintroduction helps them. And species have a far greater chance of long-term survival when their populations are widespread.

The reintroduction project in Scotland and our modern knowledge of potential sea eagle habitats and reintroduction techniques make it possible to restore this majestic bird to its ancestral haunts. But there are differing views on its feasibility or desirability.

The next step
Even in Scotland, we are again at a crossroads - with some people, including me, advocating an immediate programme of releases in new areas. Others favour a slower approach, and yet others believe it should be left to a natural spread from the present population. Using our knowledge of the very successful red kite reintroduction, we should be translocating young sea eagles from western Scotland and from mainland Europe, first to the Moray Firth and then to other suitable regions of Scotland, England and Wales.

It's possible now because people are learning to live with larger predators again, and as there's a great interest in nature, there's a reduction in persecution. Though the landscape in some regions has changed, there are new opportunities for sea eagles: many large reservoirs, big colonies of inland nesting cormorants, big increases in waterfowl and lakes with slow-moving fish such as carp. Some of the species the eagles would hunt - such as cormorants, gulls and waterfowl - are even regarded as problem species.

Just think of a future when white-tailed eagles might soar again over the chalk cliffs of the Isle of Wight or hunt for waterfowl over estuaries and marshes throughout these islands - or knowing that sea eagles are back in the western Mediterranean, the coasts of the Bay of Biscay and the great estuaries of western Europe. Maybe it's a dream, but it's a dream that's attainable.; 0

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