Leaving windows with out any hardware cloth covering them is just asking for a pred to help him or herself. Please cover your windows A drake could not do what you are describing. Sounds like coon or mink/weasel.We have had a hard press of varmints this year Raccoon too. So, they're clearly a possibility. And the skin was mostly removed from this one's neck, also.
Today, we're closing in the windows, setting traps and bedding the drakes separate from mom and the small ducks.
Thanks everyone!
Very sorry for your loss.