As a welcome new influx of cygnets make their home at the UHI campus in Inverness, investigators confirmed that the deaths last year of two cygnets at the site will remain a mystery.
The Scottish SPCA has revealed that post mortems were “inconclusive.”
A spokeswoman said “no cause of death was found.”
The tiny creatures were found dead at the Inverness campus lochan last September.
Inverness College called in the charity whose inspectors recovered the birds’ corpses from the country park surroundings of the campus on the southeastern edge of the city.
Swans have become hugely popular at the Beechwood site since it was officially opened in May last year.
Two adult birds soon settled at the small central lochan after building a nest there.
The first eggs hatched a year ago and four other cygnets were known to survive.
The latest additions fledged earlier this month.
RSPB Scotland conservation manager Stuart Benn said the post mortem mystery was a kind of relief.
“There was nothing to suggest foul play, which was the concern of course,” he said.
“We all want certainty all the time, but at times that just isn’t possible even with all the techniques and technology that we have available.
“You could say I’m more relieved in that there was no evidence that they’d come to grief through some sort of human act. That would be very worrying.
“Swans are breeding again there this year and we’ll hope they do better, obviously.
“It’s great that people at the campus are very protective of the swans and like having them around.”
