The first sign, enormous green bird scat. I don't associate green scat with turkeys, and at first wondered if this was Canada goose spoor, though it didn't look quite right. We had a long enough period of warm weather that a bunch of greenery sprang up on the forest floors; might be adding some variety to everyone's usual winter diet.
Wandering around off the beaten track a little I found another scat, this time associated with some nice clear turkey tracks--fresh, because still relatively crisp in the last little bit of snow remaining after the long period of the melt.
My guess is that the turkeys passed just a few hours before, and I could have seen them if I'd just glanced out a window at the right moment.
Troutgrrrl of Science and Sarcasm writes of a turkey roost near her home--the turkeys go to bed at 5:00. It's been my experience too that turkeys are early to bed, and not all that early to rise, so it probably would have been full daylight when they passed.