Duckling Questions

Hi Everyone!

I have become "mom" to what I think is a baby Muscovy who I named Dudley. He was found about 10 days ago in a parking lot near where I work which is an area heavily populated with Muscovies. When I brought Dudley home, he couldn't stand at all and wouldn't eat. He did drink on his on though. He has since developed a hearty appetite and has regained the use of his legs and is able to run around.

What I would like to know is how to estimate his age. He has grown quite a bit in the 10 days that I've had him but he's still a fuffly little peeper with no pin feathers. When does the adult plummage typically start to come in? Also, he's on a starter feed for chickens and ducks and I'm assuming that since it is a "starter" feed he wont be on it forever. At what age should his diet be changed and should I be supplementing his current diet with anything?

Here are some pics of little Dudders...






Thanks in advance for your help!

Stephanie