Duck kill other ducks??
Yes, How unfortunate..Your Drake did kill them.
Separate The drakes. You need more hens. Even if you find a home for the one Drake? He will need more hens. Two too six hens per Drake is a common ratio. The more hens the better. I have four hens.
Sorry for the loss....We all learn as we go.
The wounds were only on the neck. It didnt look like a predator tried to get them (or eat them) however the neck wounds were pretty severe on one of them. "Severe" meaning the injury was around the whole neck. The other duck had just a smaller area on the side if his neck.
This photo is older and was taken back in March, but its the best one i could find of all of them. I have drawn arrows to the ones who were killed.