Popped to a cold wetland reserve this evening. No sign of the bittern up to 1645. 3 yellow legged gulls came in early (adult, 2nd winter and sub adult). The tufted duck flock were tucked in out the wind but eventually pushed out. There were approx. 240 birds with this interesting ring necked look-alike. Sadly it appeared around dusk so apologies for poor photos. Head shape and bill lookeded interesting but was not really sold on the rest. Hybrid? Pochard x tufted duck perhaps? May be worth a 2nd look.