But before deciding whether to go ahead, the agency launched four months of consultation. It needs to allay the fears of some landowners, anglers and foresters who worry that beavers' effect on trees and waterways might hit them in the pocket.
If the species is reintroduced from continental Europe, probably from Scandinavia, it will be the most ambitious such exercise ever attempted in Britain. Nothing near the beaver's size has ever been deliberately brought back to these islands again by man after being persecuted into extinction.
SNH thinks Scotland could support a population of up to 1,000 beavers in the central Highlands, along the rivers Lomond, Ness, Spay, Tay, Dee, Don and their tributaries without the need to create any extra habitat.
SNH has spent two years researching whether it was feasible to bring back the beaver, and has concluded that it is. Chairman Magnus Magnusson said: "We need to be assured that the idea is acceptable to the people of Scotland."
A lengthy consultation document says that the reintroduction would "restore a missing element of our natural heritage". The species' remarkable abilities in felling trees and building dams could benefit other wildlife and create new wetland habitat. SNH is also convinced that what it calls ``beaver- watching opportunities'' would boost tourism.
The proposal has been backed by the Forestry Commission and the Scottish Wildlife Trust, a charity, which has offered one of its reserves to become home to the beaver.
If, after the consultation, SNH is still keen to press ahead, it will need to apply for a licence to bring in the European beavers from Donald Dewar, Secretary of State for Scotland. The operation and follow-up monitoring will cost more than pounds 100,000.
The dam builders
Beavers build dams from branches, trunks, mud and stones mainly to keep their burrow and nesting chamber entrance below water level.They do not always build dams, but when they do it creates large ponds and small lakes along streams. They also dig canals and construct low lodges on riverbanks.
They are excellent swimmers, with webbed hind feet, a flat, muscular tail and waterproof fur.
There are two species, the North American and the European. The latter weighs up to 20kg. They eat grass, herbs and shrubs through the summer, and the bark of broad-leaved trees, especially birch and aspen, in winter. One beaver is estimated to fell two tons of timber a year in its quest for food, but they do not attack conifers.
Their numbers were drastically reduced across Europe by hunting for their fur and the musk from their anal scent gland, which had medicinal uses. Since 1920 several reintroductions have been carried out; half have proved successful.Reuse content