If I get adults.....

[WestKnollAmy]

...do I need to keep them cooped for a week to teach them where home is?

I have always gotten ducklings.
Now I have a chance to get adolescent or adult Muscovy and wondered if I can put them in the open top fence during the day with a pool and food with drinking water and they do okay. I will be cooping them at night with my adolescent bantam roosters in a secure coop attached to the pen. The pen is apprx. 100x80 and the coop is 10x14. I only have 9 roos in there. Tons of room.

 

[Happycheese]

I personally have a 'quarantine' period when introducing animals to my main collection. If possible, setup an enclosure next to them and give a week before introducing. So they can see each other, but not (possibly) attack. I do this with rats, chinchillas, etc I don't know if it's necessary with fowl.
I also have gotten a mallard duck as an adult, I was afraid of it flying away, so I clipped her until she learned where 'home' is. I still clip just to make sure she doesnt sneak off somewhere dangerous to lay eggs.

 

[WestKnollAmy]

Mine won't be in with other ducks for a while and I doubt these roosters are going to be socializing with the new ducks.
I just wondered if older ducks would stay around but I suppose no one on here has adopted older ducks.

 

[chikky]

The first couple of calls that I got were adults. Clipped their wings and kept them in the pen for awhile. Eventually let one out, then both. They would fly (kinda) over to the grass and hang out til I put them to bed at dusk.

Just got a trio last month and will probably use the same strategy....one first, then two or all, depending on how it goes. Don't expect to let them out til later on in the summer. They're still pretty flighty. (The first ones were never really 'tame' either but didn't freak out when I came into the pen quite as much as these females do).

Good luck!