As I recall, our resident authority described the habit in which they make nests of moss on the craggy sides of the loch, hence earning the name of the "loch moss nesters," or something like that.

(It's better the way he tells it.)

In my area, most of them seem to congregate at the nearest sanitary landfill (garbage dump for those not up on the lastest "PC speak")in the twilight hours, so it would be reasonable to presume that they nest somewhere nearby.

John