Juvenile jackdaw nesting in the ash tree

I heard a kerfuffle in the ash tree and walked down the garden to get a better view. I had an idea that that calling bird was in the old nest in the ash tree's trunk just below where the broken limb has fallen away.

This hole has been there for some years from when the whole tree was intact. Originally a green woodpecker created it and brought up a clutch of young ones. Since then various animals have taken it over including squirrels and now the jackdaws. 

This bird which I presume is a nearly mature juvenile sat in the hold for five minutes before finally coming out and flying away up into the higher branches.