Playing the waiting game!

I was trying, unsuccessfuly, to find the blue tits' nesting hole while in the same area I spotted a different tree with a bigger hole and a larger occupant almost perfectly camouflaged. 

I've lived for many years but never before seen a mallard obviously sitting on eggs in a tree hole a couple of metres from the ground. The chances of seeing the ducklings leaping from the tree are slim but I will go back to Pollok tomorrow to check on the state of play.  I know exactly where the tree is so, unlike the blue tits' nest, I will be able to find it again.