The main way that I tell the difference is by the beard length. A short beard (less than 5 inches) means a young turkey around here. But, the way they act and the company they keep is another give away. Also depends where you live. If you live in the north (like where there are moose and cold icy winters), turkey's will typically not have the longer beards as the ice will break them up in the winter.

Jakes typically hang out with other jakes, while Gobblers in the spring are often alone, or perhaps with one or two other gobblers (and always looking for hens). Also, I have only once in my life seen a jake strut. If you have lots of other longbeards in the area, he will learn in short order that strutting for a hen is the equivalent of goosing a big biker gang member's wife.... its a good way to have your butt kicked. So that behavior is typically not seen.

I personally look at shooting jakes about like shooting basket rack bucks or 2 year old bucks.... can't have big ones if you shoot'em all when they are young. Heck, unless a two year old turkey puts on a good show I usually won't shoot them on our place. Nothing wrong with it of course, just how we do things.

Now telling a 2 year old turkey apart from an older bird is MUCH more difficult. Easiest way I have found is by the length of the spurs, which of course, you cannot measure until you have bird in hand, which they usually don't hold still for. Typically there again, its behavior (and in some ways the way that they gobble) that will signify an older bird.

Long story short (incase you are still reading my rambling), to quote Chris Ashely...."When in doubt.... shoot the puffy one." Killing the dominent bird is always a positive thing, as it will create chaos in the pecking order. More birds gobbling and struggling for the dominent patriarch position. The dominent bird is typically the largest of the lot anyway, not unlike deer.