I bet that's a tame turkey that got loose.
My dad raises tame turkeys for ConAgra and a couple have gotten away over the years..
The only thing with my dad's are that the wings are clipped and they are debeaked on day 1 so they can't fly or defend themselves so predators usually get them pretty quick.

http://en.wikipedia.org/wiki/Domesticated_turkey

Are there any turkey farmers in your area?