THE white-tailed sea eagle is soaring again in the skies over Scotland after an absence of almost 70 years, thanks to an initiative launched by the Nature Conservancy Council. Nature conservation in Britain is moving onto the offensive with ``creative conservation,'' a strategy aimed at restoring some of the habitats and wildlife that had been lost. In the past, most efforts have been directed toward preventing the extinction of threatened species, either through specialized breeding programs, guarding nest sites, or creating reserves. That policy will be continued by both the council (a government agency) and such voluntary bodies as Sir Peter Scott's Wildfowl Trust, the Royal Society for the Protection of Birds, and the various county nature trusts.
More and more naturalists, however, are turning their attention to the reintroduction of native species that have been lost within historical times. In most cases, human beings have have been directly responsible through persecution, hunting, or changing the habitat.
The last white-tailed sea eagle in Britain was shot in 1918, yet at one time there were more than 100 aeries in Scotland, especially in the Hebrides. Today it is breeding in Scotland once again, as the result of work done by the Nature Conservancy Council.
In 1975, with the cooperation of the Norwegian authorities, four chicks were removed from the nest in Norway and flown to Britain by the RAF. They were installed in specially designed cages on the Island of Rhum, a national nature reserve in the Hebrides, and fed until they were ready for release. Every year since there has been a fresh injection of eaglets into the stock, and in 1985 one pair bred successfully for the first time. In 1986 the same pair fledged two more young.
Since the inception of the scheme, 82 Norwegian birds have been released on Rhum. While some have not survived, and in 1986 three other pairs laid eggs that did not hatch, the scientists monitoring the project are hopeful that further breeding successes will follow as the birds become more experienced.
Encouraged by the progress made so far with the sea eagles, Dr. Derek Yalden, a zoologist at Manchester University, would like to see the island become the center of another experiment in creative conservation - the reintroduction of the wolf.
This is a very emotive suggestion and would almost certainly be opposed on the mainland, given the present intensity of sheep-farming. Wolves were once quite common in Britain but were hunted to extinction. The last one in England was killed in the 17th century, the last in Scotland 100 years later.
But, as Dr. Yalden points out, Rhum is a national nature reserve, and the only human inhabitants are Nature Conservancy Council staff. With 24 kilometers (about 15 miles) of sea separating the island from the west coast of Scotland, there is little risk of wolves escaping.
But his main reason, and ecologically it is the most sound, is that Rhum has a red deer population of 1,500. To prevent over-grazing, and to prevent the deer from starving to death, the Nature Conservancy Council culls one-sixth of the population - that's about 250 - every year.
Yalden says, ``It seems to me that the control of the red deer population should be exercised by a natural predator, and that natural predator is the wolf. The amount of meat represented by that cull would support a pack of about 19 wolves.
``There are further attractions about this as a procedure. Despite the cull, the stalkers are not accurate enough to kill the deer that are weak or vulnerable because another 50 or 60 still die during the winter. The trouble is that a deer is not capable of escaping from a well-aimed bullet whereas a fit deer is capable of escaping from a wolf. Conversely, a sick deer is vulnerable. Thus it would result in a healthier herd because the selection pressure would be more accurate.''
He also points out that with wolves on Rhum there would be a supply of carrion throughout the year, not just at the end of the winter as now. This would benefit other forms of wildlife, notably golden eagles and ravens.
One side benefit, and one not to be ignored in the Highlands of Scotland where unemployment is high, is that it would encourage tourism to the island.
``A lot of people go to East Africa to see, or at least to have a chance to see, lions stalking wildebeest or cheetah chasing gazelle. At present you cannot see that sort of predation anywhere in Britain and this would be an opportunity to put that right,'' he argues.
Yalden would also like to see some thought given to the reintroduction of two other mammals that have been lost to British fauna within historical times - the beaver and the wild boar. As both are creatures that need deciduous woodlands, Rhum would not be suitable, but he thinks that the beaver might stand a chance of success in some of the remoter areas of the Lake District. With Britain's shrinking forests it may be more difficult to place the wild boar but, as he points out, it does roam the forest of Fontainebleau on the outskirts of Paris.