I’ve been trying to work out what the optimum conditions are for bird migration, and it seems to be a combination of a clear night followed by a sunny day, with just the right amount of wind – at least, that seems to be what Wheatears like as, both on Wednesday and today, they have been moving through in reasonable numbers, with some stopping off locally en route to their southern over-wintering grounds. These are a few I’ve been privileged to spot in recent days …