shoveller behaviour - january

[paddy]

Braving the freeze at Titchwell RSPB yesterday, i watched a male and female shoveller, heads down in the water, rotating together. They were just below the path, impervious to any humans, and carried on from at least time of arrival (1pm ish) until dark.
I would imagine it was some kind of 'pairing up' ceremony, but have never seen it before. Any other suggestions?

[loripo]

They often do that in large groups, heads down stirring up possiblye food from the bottom, and following each other round to benefit from each others movements.

[paddy]

the thing about this was that it was in exactly the same spot - they only moved about 2 or 3 feet all afternoon.... i would have thought they might have exhausted the supply there and moved on. No other birds joined them, although there must have been 50 pairs within shovelling distance...

[Dogghound]

It sounds like they were feeding, they often do this as you saw by rotating or going along in lines. The do alot of feeding from the surface by filtering water through the fine serrations along the bill.