Okay -
They gobble from the roost to inform thier hens where they are......then gobble at fly down to assemble their hens....then once gathered they strut for their hens till the hen feels like mating.....they may not gobble again till the hens leave them....they may shock gobble.....that is talk to a crow call, woodpecker call.....or another hen call.....but if you are not hunting - do not use a hen call....

And I don't think it is ever to early to scout......you found 4 - though on private land - find a place around there you can hunt......and you did hear a gobble on a ridge - is that huntable? did you try to check that out by walking the area......remember it is not a good idea to use any turkey calls as you could educate the bird.....don't wanna do that!

JW