Wondered what was going on, so followed and asked some bloke who had travelled up this morning from Watford & he told me that yesterday morning there had been a reported sighting of an American Kingfisher on the river just down the road and everybody had come to see it (and to expect people from all over Europe in the next 24 hours). Unfortunately no-one had seen it yet today.
We went out and came back mid afternoon and everyone had gone. My guess is that the twitchers had fallen victim

Any other "good ones"?