@splendens I agree that these aren't Ring-necked Ducks. Female Ring-necked Ducks have dark eyes not yellow eyes, so that rules out the possibility of the female belonging to that species. Male Ring-necked Ducks have gray sides not white sides, so neither of the males can be Ring-necked Ducks. There may have been Ring-necked Ducks in the exhibit with them, but these aren't them. My opinion is that the female in the lower center of the photo and the male on the lower right are a pair of Tufted Ducks (Aythya fuligula) and the male on the left is probably a Greater Scaup (Aythya marila).
