An investigation into the deaths of 16 swans found at Fairnington Loch, near Kelso, in December has shown that at least five of them were killed by lead poisoning.
However, just how the swans were poisoned remains a mystery, as does where they ingested the lead.
The grim discovery of the whooper swan carcasses was investigated by the Royal Society for the Protection of Birds Scotland and, in a bid to avert further such deaths, South Scotland Labour list MSP Colin Smyth last week raised the matter with Roseanna Cunningham, the Scottish Government’s cabinet secretary for environment, climate change and land reform.
He wrote to her “to ask the Scottish Government what cause of death was determined in relation to a group of whooper swans found dead in the Fairnington area of the Scottish Borders in December 2017 and January 2018”.
The minister replied: “Five of the 16 recovered whooper swan carcases found dead were identified as having died from lead poisoning as a result of ingesting lead of an unknown type and that they had not been shot.
“The cause of death for the remaining 11 whooper swans was not identified, although, as they were found in exactly the same set of circumstances, it is highly likely they suffered the same fate.
“However, this could not be confirmed during post mortem due to the advanced state of decomposition in most of the carcasses.
“It is not possible to say where and when the swans ingested the lead. It is understood the swans migrated from Iceland to the UK for the winter and the lead could have been ingested anywhere on that journey or before, during or after.
“There is no evidence to suggest the swans ingested the lead over a wetland area, although this remains a possibility. There is no wildfowling undertaken at the location where they were found.”
Mr Smyth then asked what steps the Scottish Government is taking “to ensure there are no repeat episodes”.
Ms Cunningham said: “Given that the causes of death were inconclusive, there is no guarantee that any steps the Scottish Government takes would prevent a repeat scenario.”