I haven't experienced mink (and you may be right!) I was thinking coon because I have a friend who has a very open barnyard where only the large hoof stock are fenced. The property borders a very swampy lake. She has problems with poultry losses (chickens, geese and ducks) in the fall. The bodies when found are usually next to the bank of the lake, sometimes they are found in the corn field that also borders the barn.. It's been obvious by the tracks that the kills were made by racoons. The barnyard is clean, the coons grab whatever and take the bird to somewhere else to eat it - if they eat it. The bodies are usually intact for the most part but the necks and heads are bitten or eaten.
If her birds where penned - I'd expect different. They do keep cats at the barn too and cat food is there but the coons would have to go in the tack room to eat the cat food, I imagine grabbing an outdoor duck or hen is easier.
If her birds where penned - I'd expect different. They do keep cats at the barn too and cat food is there but the coons would have to go in the tack room to eat the cat food, I imagine grabbing an outdoor duck or hen is easier.