Aerial surveillance is needed because ground searches of the Glencolumbkille area by dozens of farmers have failed to detect which local forest plantation the dogs are operating from. Marksmen from England and Northern Ireland have attempted to halt the slaughter by shooting the dogs, but without success.
The 42 affected farmers, who have formed their own watches to guard against renewed attacks, are convinced from the frequency of the attacks that the animals are living wild.
"They are hiding in forestry and it is very difficult to get them", said Christopher O'Connor, local representative of the Irish Farmers' Association (IFA). "In other cases, where [domestic dogs] were returning home after attacks it was a bit easier to control them."
The dogs, apparently pets gone wild, began their killing spree in the peninsula west of Killybegs and Ardara last November. Many more sheep have been attacked or gone missing than have actually been eaten.
Mr O'Connor said with the almost daily killing the situation is becoming more urgent. "When they get a taste for it, their most savage instincts come out. At the moment most of the sheep are down off the hills for lambing. But the farmers are running out of grass there, and want them back on the hills, so they are very anxious that the dogs are caught."
Farming sources say the problem is particularly acute in Spring with the birth of new season's lambs. Pastures filled with heavily-pregnant ewes or newly-born lambs provide an irresistible temptation to canine predators.
The economic consequences of attacks at this time of year for farmers are serious, the IFA stresses: "Killing of young lambs means the cash crop for the year is destroyed." Poor land quality means sheep and forestry are the only viable farming activities in the area.Reuse content