Phil - I just need to ask - but if the birds don't like to enter the fields - then why do you even hunt in the fields?
I don't think this is overly unusual in the Northeast. In all of the Northeast, the fields in May and June are usually more than tall enough to hide a coyote - I mean, most farmers try to harvest the first-cutting of hay before school gets out in the middle of June.
When I lived in CT (almost 20 years ago now), the birds would gobble their brains out in the timber and immediately shut up as soon as they hit the fields. In the 8-10 years I hunted there, every time I was on the edge of an ag field or clearcut (pipeline or electric) I was always watchful for coyotes - and over the years I called in almost 2 dozen yotes to those setups. Every bird I killed in CT - except 1 - I harvested in the timber, and they all gobbled into the gun.
It would seem more productive to set up close to the roost and/or at least stay in the woods. I know you like to use a bow - but portable blinds work just as good in the timber as they do in the field, turkeys will usually walk right by them...