In my experience you want to get to your fields early afternoon before evening.
Most of the time a dominant Tom will stay with his hens and possibly have a stray
Jake holding with him. The tom will not leave his hens to the Jake so he will hold
tight and not leave the hens to the Jake by responding to an evening call. You
have to be in the most likely spot that they may all feed and pick up gravel
for the gizzards before going to roost. If say you see them in another field on
an evening hunt, you can almost give up calling and start stalking right away.
They will be so busy filling their belly's that you may crawl right up to shooting
distance. Be prepared to cover about 150 yards on your hands and knees in about
an hour and a half. If one bird even raises its head stop. At about fifty yards your
heart will start pounding thinking one of them will bust you. Just freeze, look and
move only when all heads are down. With LUCK you might get a shot. It will be worth
every crawling step.