@Jpat Krista is here!!
Ok so the fact is true! Ducks, chickens, large bird poultry do not have the muscle needed to control their bathroom needs. Some people use diapers. Some people have claimed to potty train their large bird poultry but all they did is show the poultry grass and give it the option to get outside on it's own as it pleases. They simply feel safer and more natural going potty in the grass compared to indoors so given the option and opportunity to come and go as they please, they probably will poop outside MOST of the time. Other people like myself use different methods of indoor keeping. I keep towels and blankets down underneath my duck and her pen. They get washed as needed and refreshed. I also work in puppy pads sometimes. I only use a diaper if we go into someone else's home. My duck isn't sick and has a yearly check up at the vet with proper vaccines... so no salmonella. Higher chance getting salmonella from their eggs than the poo.