The Bornish site in South Uist is one of the most extensive and complex Norse settlements on the Western Isles and also one of the largest rural settlements of its type in Britain. It is thought to have been the home of a prominent Viking figure who had political control of the islands and close ties with the Norwegian king.
According to the Scotsman the site is being heavily disturbed by rabbits. Niall Sharples, senior lecturer in archaeology at Cardiff University, who is leading the current work, said: "There will have to be a decision about the long-term preservation of the site, as it’s being badly damaged, particularly by rabbits. That is one of the main threats.
"The long-term future of the site depends on the local crofters negotiating some kind of stewardship scheme."
A survey has revealed a complex of more than 20 houses covering an area of more than two acres. The site spans the period of the Viking conquest of the islands and includes evidence for the preceding Pictish period as well as an early Viking building dating to at least the 10th century.
During the 11th and 12th centuries the settlement expanded and it appears to have encompassed at least five or six separate farms.
Mr Sharples said: "Large settlements such as this are extremely rare in the Highlands and Islands, and one has to go to the important political centres of Birsay in Orkney to find anything comparable in size.
"At the centre of the settlement are a number of very impressive large buildings, which clearly indicate the presence of a family of considerable status who would have been amongst the ruling elite of South Uist if not the Hebrides in general."
He added: "It’s a very important site. From what we have found it looks like the people there were connected and traded with southern England, Ireland and Norway in the 11th and 12th centuries.
"The person who stayed there would have been a Viking of lesser nobility. He would have had political control of the islands and an influential player in the political movement of the west coast."
The eighth and final season of excavations at the settlement began this month and will continue until 20 July. Excavations this year focus on a large mound that appears to be the centre of the settlement and a smaller mound that is a later development and includes three substantial houses that span the 10th-14th centuries.
An indication of the wealth of the inhabitants is the quantity of artefacts found, including complete pots, iron cauldron handles and the cut-up remains of an iron cauldron, knives and other simple iron tools, large numbers of bone dress-pins and bone combs.
Imports include a pot from the Bristol area of England, bronze pins from Dublin and a decorated bone cylinder from Norway, which might be the mouth of a drinking flask.
Mr Sharples said that one reason for the wealth and expansion of the settlement might have been the control of an important fishery. An examination of the site’s middens has found a large number of bones of herring, a basic food for towns such as Dublin and Waterford, which were established in Ireland in the 10th century.
"It seems likely that the inhabitants of Bornish were using the abundant fishing resources of the western seaboard, and the presence of a reasonably sheltered anchorage at Aird a’Mhuile, to develop a commercial fishery and to enhance their wealth," Mr Sharples said.
"What we have still to establish is whether the fish were processed at Bornish and how they were preserved for shipping to Ireland."