Look what I found

I was cutting back the Sambucus Nigra  which I do every year, so as to keep it medium sized bush  next year, as it's primarily an Elderberry and the can get out of hand., and in the middle was this nest. I think it is a Blackbirds nest as I kept seeing one bobbing in and out of the bush in summer. Hope it comes back next year.
Should I remove the nest or will it reuse it I wonder, mmm apparently they build new nests but often recycle some of the old nest material. 
I was having trouble cutting some of the branches when a knight in shining armour (in the shape of my window cleaner)  came to my rescue and cut them for me, wasn't that kind of him.

It's been a very pleasant day cool but sunny