I don't know the answer. Maybe try the Bird Watching Forum if nobody else answers here soon.

Here is a link that might be useful: GW Bird Watching Forum

I think Moscovey ducks are a South American species. I expect they nest, around here, in Spring. They would be prey to any number of animals. Just here in NJ they would be preyed upon by fox, racoon, coyote, hawk and owl, to name some. Swimming babies would be taken by snapping turtles and even a really big bass. I lost my chickens to a neighbor's dog that has gotten loose.