PERVERSE though it may sound, environmental degradation has its advantages. Such is the extent of overgrazing on Mayo's Clare Island that it has exposed the largest collection of fulachta fia or burnt mounds on any Irish off shore island.
Some 54 fulachta fia have been identified to date, according to Dr Paul Gosling of University College, Galway who will present his findings at a seminar in the Royal Irish Academy (RIA), Dublin, today.
A similar archaeological survey of Clare Island carried out under the guidance of the naturalist, Robert Lloyd Praeger, in the early part of this century found only four of these ancient cooking places - because the island's heather was then so high that it could hide a sheep!
Now, due to overgrazing, the heather is almost invisible and the island's unique environment is under severe pressure. The RIA's multi disciplinary survey of the habitat, which is the only scientific project of its kind in Europe, has discovered that over 40 plant species have disappeared. Birds like the skylark have also vanished since the original survey by Praeger and his team of Edwardian naturalists in 1909-1911.
Dr Gosling, who is due to deliver his final report on the archaeological section of the RIA survey today, says the most significant result of his research programme is the discovery of a megalithic court tomb at Lecarrow. This has pushed back the earliest horizon of human settlement on the Clew Bay island from the second to the fourth millennium BC. The large numbers of fulaclztafia and other monuments, amounting to 198 in all, point to a relatively intense settlement there in the Bronze Age.
"This begs the question: why?" Dr Gosling says. "The geologists involved in this current research programme have found no traces of significant minerals, but there were two large deposits of chert, a type of flint. Or it could just be "because the western Irish islands were European routeways during that time.
If Clare Island was buzzing in the Bronze Age, it was also densely populated in the last century, according to Mr Criostoir Mac Carthaigh of UCD's department of Irish folklore, who will also speak at today's seminar. The profusion of spade cultivation ridges and remains off dwelling houses are indicative of this, it was a "desirable destination" for migrants fleeing the congested districts on the mainland, and the population numbered about 1,600 at the time of the Famine.
The island had a rundale system of agriculture until the close of the last century, when the Congested Districts Board "striped" the land, Mr Mac Carthaighays. This "massive" fence building programme, and construction of an east west wall to separate cultivable land from commonage, profoundly affected the economy.
However, it also preserved an ancient system of land and livestock management which has continued to this day. The islanders were also involved in a significant herring fishery in Clew Bay until the 1930s, using double ended Achill yawls, he says.
The publication of Praeger's survey in 1915 marked the end of the "golden era" of Irish natural history, Mr Tim Collins of the centre for landscape studies at UCG says. The diversity of species recorded by Praeger was "quite staggering", with over 3,000 types of plant, almost 600 of which were new to Ireland, over 50 of which were previously unrecorded in either Ireland or Britain and 11 of which were new to science. Over 5,000 types of fauna were listed, some 100 of which were new to science.
Praeger's multi disciplinary approach has not been matched anywhere in Europe until now, Mr Collins says - although smaller surveys of Mayo's Mullet peninsula by the University of Reading, and of the Scottish island of Mull by the British Natural History Museum have been modelled on it.
"Insular" takes on a new meaning in the study of place names on Clare Island. Dr Nollaig O Muraile, of the department of Celtic studies at Queen's University, Belfast, has noted a startling degree of "localism". People at one end of the island were often quite unfamiliar with names which were well known at the other end.
Sponsored principally by the Heritage Council and the Discovery Programme, the new RIA Clare Island survey will continue with its zoology, botany and geological sections.
Today's seminar in the RIA, 19 Dawson Street, Dublin, begins at 10 a.m. Admission is free.
