If I were picking them for human consumption I would leave them another few days because they are still not 100% ripe, but the Blackbirds are obviously not so fussy. [I hope they get the bellyache!]
So, there was obviously a need for urgent action. The first thing I did was move the pot of Blueberries with the nearly-ripe berries on it into the garage whilst I made a plan...
I realised that I'd have to either erect a net or lose the whole crop. Once the Blackbirds have identified their target only physical barriers will deter them! Fortunately I found that there were some masonry nails in the wall, left over from years ago when at one time I had some Clematis plants growing up the wall. I attached a net to these and brought it down at an angle so that it stood away from the plants.
I weighted-down the edge of the net with my potted Chives. It's not brilliant, but it's the best I could do in a hurry. Next year I must think about this earlier.
So now this is the Blackbirds-eye view of the berries:
Let's hope it works!