At my lease in Carolina, the birds gather up into winter flocks in November - February. Then, if the weather warms up, they disperse in March. We had a group of 13 gobblers running together on our 190 acre piece. But after they split in March, the most we saw or heard together was 3.
From what I understand, they establish their pecking order, then in the spring they spread out to give each other their areas. Of course in areas with large populations of birds, with good food sources, you'll have a lot more birds hanging around.