I'm not sure whether I should dive into this or not as I certainly don't want to ruffle feathers and I am the new kid on this block. Those are some pretty steadfast answers and not necessarily true but yet hold alot of truth. LOL One, pheasants are very susceptible to disease which are carried by chickens. Do you have birds that have those diseases or better yet carriers of them....don't know. It depends on your local (PNW has less problems than say the midwest, south or Texas) (Desert less problems than tropical) and also how clean you keep your pen and also what measurers you take for prevention(worming, etc). I have very healthy birds and have passed rigourous inspection, and I keep some pheasants side by side with my chickens.
Do they get along? Yes and no. It will depend on your birds, sort of like putting a new kid in with a couple on the playground. Some do and some don't. A sure way to make it work is to have a hen hatch them. A good hen will raise them as her own and they will assimilate just fine.
Can you have them with an open top. The answer to that is not usually at first, but once they have become accustomed to your place, the can come and go as they please. I have several "escapees" that have been with me for years. I have lots of cover for them and they like it where they are at, especially when I throw treats etc, so they happily flirt around my pens and yard. The worst thing they do is harass the males in the pen and distract them form what they need to be doing, though I have found it might stimulate the pen males to be even more tending with the females. Thats a whole different story. Again, if a hen hatches the eggs, they will stick with the flock as if it were their own. If you buy adult birds that are unaccustomed to your place, a top wire would be necessary for some time until the get accustomed to your place and you.
