Hi,
First of all, could Glenmoran be Gleann Meurain? It's north of Loch Lyon, with Moar being east of Loch Lyon. The area is now flooded, following the construction of the dam, but there used to be settlements there, such as Invermeurain. It's quite remote, and a long way from Runacraig on Loch Lubnaig. How did you make the connection?
There was a Clan Gregor family who lived at Runacraig for several generations, and during the proscription on the surname they went by the name Buchanan. I can trace them to a couple who married in 1747 called Patrick Buchanan and Catherine Drummond. Drummond was also an alias, as Catherine was also a MacGregor.
At the time of their marriage there were several families from Clan Gregor living there. They may have been siblings of Patrick, but as Patrick's children appear to be the only descendants to stay on there, I suspect they were from another family living at the same location, possibly Patrick's cousins, and they later moved out of the area. They were; Alexander, John, Robert, and Duncan. All except Duncan used the alias Buchanan, Duncan went by Gregorach, Stirling, and Drummond, as well as Buchanan.
Your Donald appears to have no other entries in the Balquhidder Parish Register. He may have been part of the family above, but he also could have been a shepherd, or farm labourer, who only lived at Runacraig for a few years before moving elsewhere. Did you select him because you know he moved into the Glen Lyon area after 1743?
The registers are not a complete record, especially at the time of the uprising, and the surname proscription makes it hard to trace members of the clan. So, Donald may have had more children at Runacraig, and may have been a member of the family that lived there.
Patrick's family have a tradition of being from the Glengyle branch of the clan, as does mine, and one of his descendants was a neighbour to my ancestors in Glen Buckie. The Glengyles had a habit of living in communities of extended family.
I hope this helps,
John.
