Tufted Duck
Aythya fuligula
A fairly common diving duck in winter, but not as common as a resident. The males are a striking glossy purple-black and white with a long tuft from the back of the head. Some are very shy, others very tame, depending on location. The females are browner and have shorter tufts.
 
  
  
1: Black Swan Lake, Dinton Pastures LNR, 02/03/2007.
2-3: Radipole Lake RSPB, 26/01/2006.
4: Radipole Lake RSPB, 23/01/2007.