I took this photo this morning (18 MAR 2023) at the Edwin B. Forsythe National Wildlife Refuge in NJ. I have looked up all the ducks I can think of with a head that color, but can't find a good match. This guy was feeding right next to some blue-winged teals, and was easily 1.5 times as big as they were. They were both feeding in the mud at low tide, so there may be some feathres obscured by mud.