Posted by Phil A. on January 01, 1970 at 00:00:00
I've seen these birds before. They have been in my backyard a few times. Here's a checklist from 2017. https://ebird.org/view/checklist/S41217855 . I asked Tony Leukering about them and he suggested I report them as Muscovy Duck (Domestic type). He wrote in an email: "Your duck is at least partly Muscovy Duck. While I cannot think of anything with which Muscovy Duck could hybridize to produce this bird, your best bet is probably to use the "Muscovy Duck (Domestic type)" entry for the bird."