Quite an old thread but still relevant. Seeing the posts by William & nmonks about mallard ducks brings back memories of Mother's Day weekend about 7 or 8 years ago. My wife and I came home from playing golf on Saturday before Mother's Day and there was a female mallard duck sitting on the ground unter our porch swing. We live next door to my parents and they said they were out in the yard that morning and the duck walked out of the woods behind the house and walked all the way to the house (about 200 ft), quacking all the way.
My dad opened the gate to their back yard and kind of herded it through the gate. It got in their goldfish pond and started swimming around. Over the rest of the day and Mother's Day Sunday, it was back and forth from their back yard to our back yard (also a goldfish pond). We fed it cat food (obviously, didn't have any duck food). It seemed happy as could be. It was in my parents pond late Sunday evening. Monday morning, my dad went out in the back yard and he said it flew off out of the pond and up over the trees out of site.
What was kind of odd about the whole deal is that our last name is Duckworth and we always called my dad's mom (had passed away several years before) "Granny Duck". So mom and dad decided that this was just Granny Duck coming to visit us for Mother's Day weekend.