I think the difference in primary habitat has more to do with the impact that predators have on Turkey poults. Primarily Wooded areas vs. agricultural/hedgerow has to significantly reduce the affect of winged predators (since most hawks rely on open areas to hunt) and feral cats which go with rural/farm habitat like peas and carrots as well as raccoons and skunks wouldn't you think?

I think with respect to turkeys it's coyotes and gray foxes with a sprinkle of the rest mixed in VS a large dose of EVERYTHING going against the pheasants.

Besided it's kind of hard to have baby pheasants to even start with if we have no breeding adults. Turkeys have a big advantage based upon size and smarts of the adults alone.