At least 15 swans have been killed in Donegal after colliding with overhead electricity lines, according to BirdWatch Ireland.
The bodies were discovered lying under electricity lines close to the village of Carrigans in the north-east of the county, close to the border with Northern Ireland.
A member of the public made the discovery today and informed BirdWatch Ireland who travelled to the scene along with a local National Parks and Wildlife Service ranger.
They confirmed that the Whooper Swans had collided with the wires in flight and that the cause of the birds' deaths was electrocution.
A high proportion of the swans that were killed were juvenile birds, just a few months old.
BirdWatch Ireland said it appears that the deaths were the result of multiple separate collisions with the electricity wires over a period of several weeks.
BirdWatch Ireland said it has contacted the ESB to inform it of the problem and to recommend that immediate measures be put in place to prevent further collisions.
Niall Hatch of BirdWatch Ireland said: "Ireland hosts internationally important numbers of Whooper Swans each autumn and winter, and it has a special responsibility to conserve and protect them. We sincerely hope that measures can be put in place to prevent further swan deaths as soon as possible."
Whooper Swans are winter visitors to Ireland, migrating here each autumn in family groups from their nesting grounds in Iceland.