SINCE Sunday, April 15, I have seen quite a few swallows round the Selby district.

I believe these are earlier than usual but, as I don't keep natural history records, I cannot be sure.

I am wondering if any experts in this field could tell us and, if they are early, is this another sign of global warming? Talking of which, I see there is to be a big concert in the summer, in London, I believe to make the general public more aware of global warming. I wonder how much electricity they will use for this?

John Rogers, Northfield, Barlby, Selby.