The Return of the Shoveller Ducks

We are currently in the middle of the first cold spell of the winter.  Here in the south of England that just means a run of nights in which the temperature drops below freezing point.  Yesterday afternoon we thought it worth going round the university lakes to see if if there were any interesting migratory birds that had been pushed down from the north by the cold weather.  Sure enough, there were 20 to 25 shoveller ducks in two rotating groups on the large lake.  I seem to remember seeing a small number of them, 6 to 10, on the lake a few weeks ago, but the cold weather had certainly brought in more.