I've raised them in several different situations over the years. The most important thing to remember is that chickens carry a fatal parasite, blackhead. The chickens are immune and show no symptoms, and almost all chickens with access to the outdoors are carriers. So you have to keep turkeys and chickens well separated at all times. No overlapping pastures, etc. Even so far as, if you do raise both, always do the turkey chores first, lest you track chicken manure over to the turkey area! Old heritage turkeys, especially fully grown ones, often show some resistance....thus explaining the occasional spectacle of a farmyard where they seem to coexist.
Turkeys in general are more persnickety than chickens. They need a higher protein diet when young, and seem more prone to dying off from various causes....If you get a breed that can hatch and raise their own young you might have better luck than with an incubator, etc. Modern "broad breasted" turkeys are even worse than the "meat chickens"....as far as clumsiness, etc. goes. The toms can't even perform their masculine duty effectively, so they are often artificially inseminated. Even with heritage breeds, keep the tom away from new hatchlings....walking around puffed out to impress his woman, he can't see his own feet, and winds up stepping on the chicks, often killing them!
On range, turkeys will scratch less and hunt for insects more as compared to chickens. Years ago we had some in the same pasture as a dairy cow, and they would follow her around and pick off the horseflies. Eventually the cow learned to lie down when the flies were bad, and let the turkeys walk all over her to get at the flies!! Also the birds would scratch the cowdung completely away into the grass looking for bugs and worms in it....
I raised Black Spanish Turkeys with great success. Or rather, they raised themselves. Started with 25. Ate 20 and kept the biggest and nicest tom and 4 hens. They turned into 40 turkeys. Raised their own babies. And I even managed to get some of the eggs – delicious.
My grandmother always kept all of her poultry together so I did the same. No problems. They had approximately 1+ acre to wander on.
The turkeys were great grazers and clipped all of the seed head off of a little nut grass that was in the lawn. Food for them and good riddance for me!
They were much more personable that the chickens and when allowed the in the ‘people’ portion of my back yard, would come up and hang out with me. I have lots of pictures and many fond memories of the Black Spanish. They are the oldest domesticated breed and it takes a trained eye to tell the difference between them and a wild turkey.
I kept their wings clipped because they will fly off, and even with wings clipped they managed to get up on top of the muscadines at night or the top of the poultry house. They need a place to get off the ground to roost.
I fed a whole grain scratch (no pellets/processed food), used a small paddock shift type system – and fed pumpkins, sunflower (that I grew) and kitchen scraps. The whole grain scratch that they missed would reseed itself so they had those plants to eat on the next rotation through that little paddock.
I dearly loved my turkeys and look forward to having them again on my next place.