I've spent the day looking through a pot of beetles putting a name to them and gluing them on bits of card. I find that this satisfies the OCD urges within me. Whilst doing this I heard a thump on the back window, having heard this sound before I knew that a bird had flown into it. It's usually a wood pigeon leaving an angel like farina dusting on the pane. This time no wood pigeon but a knocked out Greenfinch. I nursed it in my hand for about 5 minutes, then placed it on a perch where it sat first one legged and then two legged for about 10 minutes. After this a short flight onto next doors trellis, followed by a more substantial flight several minutes later. Hopefully it will recover. Gave me a chance to get up close though.