Hello Alisdair. Unfortunately I am not a bird expert. I await a visit from Melissa Hamilton to identify them as nightingales for me. However I am 95 percent sure they are not blackbirds singing as I have been listening carefully . And yes, they are still here, especially during the day.
Melissa made a marvellous identification two years ago of Leiothrix. It is a pekin robin, an escapee which turned up near Lucca about six years ago. I leave some clusters of grapes at the end of the season for the birds, this year the pekin robins have been plentiful, and very pretty as they dart from olive tree to grape.
You mention hedgehogs. For fifteen years I have been fortifying the perimeter fence to keep out wild boar and porcupines. I was very surprised, in these recent damp days, to find that in two places someone is trying to dig a way out of the garden. It might be hedgehogs which I occasionally see. Or could it be toads? I am wondering if I should provide some kind of tunnel to let them out, but the porcupines would soon find a way around that.