Thank you for the tip! I will read up and sacrifice some bunches. I should shove the netting on sometime soon - it's nowhere near time but I will be cross if I put it off for so long that the birds wade in again! In theory (she says hopefully) in the longer term if I train it properly the leaves on the top should keep the birds off the grapes underneath. That has worked well with other berries in the past. I don't really bother training the raspberries properly so they sag all over the place and we don't seem to lose any to birds, who I assume can't easily spot them from above.

Which reminds me, I should probably have a look at the apple tree as well -- it's only a little one so could probably use some of the apples being thinned.