Speaking of turkeys from behind - I've had success in the past sneaking up on them from behind, but you have to wait until they're in full strut.

I've closed the distance by 10-20 yards to get them in range.

A gobbler's field of view is limited by his tailfeathers when in full strut. You can use it to your advantage.

Off the topic, I know, but a noteworthy tactic nonetheless.