Like paparazzi, they stand with cameras poised awaiting the emergence of their quarry.

But their target is nothing so common as a C-list celebrity lurching out of a nightclub.

The star in question is a white-crowned sparrow. This tiny visitor from North America has been spotted in these isles only four times before - and never so far from home.

Which is why the Norfolk village of Cley has been overwhelmed by an influx of twitchers, distinguishable by their anoraks, binoculars, hi-tech lenses and hushed excitement.