I think I see what’s happening here. So a true “snowy” colored duck happens when there are two copies of the harlequin gene because harlequin is recessive. Snowy is technically just a mutation of the mallard “wild” or “grey” pattern that causes where the darker browns/greys are to be lightened. See the drake here on his shoulder area? He is not carrying two copies of the harlequin gene. You can see the “wild” gene showing through right here. One copy will cause a lightening effect to varying degrees, but not be true snowy. The wild gene is dominant and since the harlequin gene is a lightened mutation of the wild gene that is why you are seeing so many mallard/wild patterned ducklings.
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