Thanks everyone. The ONLY things I have read about the swans and feeding is that moldy feed will kill them. Well they eat so much that the feed never gets a chance to get moldy.

As far as pinioning the mandarin, I was thinking of just keeping them wed fed enough so that they would keep coming back each year. I was concerned that if I pinion them, they wouldn't be able to fly into the nesting boxes. The two pair stay together always, so I feel that we will have good breeding success when they are old enough - when would that be BTW ?

The swans came pinioned (I wouldn't want THAT investment flying away), but it turns out that the black species of swan isn't migratory, and stays put for its lifetime.