Nope, but I'd love to hear your experience with them. Someone I sold ducks to last year was working with the extension office to set up a hatchery here in NC. Unfortunately, he suffered a severe injury later in the year and ended up having to sell his operation, so sad, but so far it sounded like he was getting a lot of valuable assistance.
Well, I contacted our local program to find out if they had any resources on plants that are toxic to ducks. Got told no resources that ducks will just naturally stay away from toxic plants. Person answering had chickens, not ducks.
I would think that to be true as long as there are plenty of non-toxic foods for them to eat. We free-range our waterfowl, and they get most of their food from their environment. We've never lost one to poisoning, though I did have one get a case of botulism earlier this year. When we have areas under crop production their ranging is more limited and I am careful to monitor whether they have outstripped their range of natural foods and give more feed to compensate.
If an animal is in starvation mode they are more likely to eat something that isn't good for them... humans included.