Thanks Jurek, I´ve located a few holes in the neighbouring woods that might belong to the local GSW, all in dead upper branches of trees. I was surprised to find that they make holes in quite thin branches. As far as I understand, a pair tends to make a few different holes, some for roosting, one for nesting, and others that never seem to get used. Do you know if GSW re-use the same nesting hole? Or if they tend to nest in the same tree/trees? Also, what is the average height of a GSW hole from the ground? (The local one this year was over ten metres).