Depends if you messed with it before you took the picture. Spring bear poop goes black on the exterior pretty fast when exposed to oxygen. So generally speaking if you find it all green chances are it's pretty fresh. If I find a green pile I will definately stick a finger in there to see if it's warm. Warm...no more than an hour old. If it's fresh enough you don't need to put your finger in...get cocked, locked and ready to rock! It's game time

If it looks more fiberous than slimy chances are it's more than three days old unless it's been raining. If pretty much black all the way through it's a good chance it's more than a couple days old. But the only way I know how to tell the exact time it was dropped is when it's still hanging on when I take the shot

Warning: Never stick your finger in poop you see worms in. No need to check the freshness cause you really don't want to be shooting that bear! Pigs, Bear and Buffalo are known to carry the trichina worm (spiralis). One of the three round worms known to cause trichinosis. One of the reasons I always carry a pocket and glove box full of surgical gloves when hunting pigs or bear.