An organisation which has pledged to wipe out grey squirrels to protect the native red squirrel has been established in Ireland.
Mr Charles Dutton, a director of the European Squirrel Initiative, told a forestry conference in Tullamore, Co Offaly, that grey squirrels cause devastation to forests and woodland.
"Their habit of stripping the outer bark from the trunk and branches of trees in order to eat the soft inner tissue results in the growth of calluses and loss of timber quality," he said.
"In severe cases up to 25 per cent of the crop can be lost completely, resulting in destruction of habitat and substantial financial loss."
Another consequence of the spread of grey squirrels is the loss of the native red species, he claimed. "Grey squirrels have forced red squirrels out of most parts of Great Britain and are now making real inroads into Ireland," said Mr Dutton. "While red squirrels are able to live in harmony with woodland and native wildlife, greys damage trees, deprive wildlife of food and raid birds' nests. They also carry a disease, parapox virus, which is deadly to the reds."
The American grey squirrel was first introduced into Ireland in 1911 at Castle Forbes in Co Longford. It now occupies some 30 per cent of Ireland and the population is growing fast. In the north of Ireland, efforts have been made to establish strongholds for the red squirrels, but the conference was told that even these areas have been infiltrated by greys.
Mr Michael Carey, a previous chief director of Coillte, described the American interlopers as "tree rats".
Mr Dutton said the European Squirrel Initiative was a non-profit-making company founded in 2002. It campaigns for the protection and re-introduction of red squirrels throughout Europe.