Our camp is in the middle of "bear central" here in Pa. A few observations, as we've seen and watched many.
The younger bears and cubs are, for the most part, the climbers. Big older bears aren't so inclined to climb trees - especially younger trees that, once they lean on them, they determine that they aren't safe to climb. Big, older, woody trees - they WILL climb, but the trees are woody enough to take some damage and still survive. We have a couple such older, woody trees at camp. I watched some younger (?), smaller bears of 75 to 150 lbs. or so get too greedy and go out too far on limbs for more apples. They fell from 20 to 35 ft. to the ground and hit with a noise that you had to hear to believe. They ran away from the trees at FULL speed wailing all the way. I doubt they ever tried that again!!!
As for apples being on the trees .............. I hate to burst everyone's bubbles, but bears will reach up and put their paws on any branch they can reach ............. just to stretch, or just to explore. No apples on the trees in spring!! Again, it seems it's mainly the younger bears - probably just exploring every nook & cranny, every new or challenging thing. We've seldom seen older bears reach up and "toy" with tree limbs. For those reasons, I try to prune off the lower limbs so that the lowest limbs are at 6 ft. - or higher - above ground. We also stake concrete remesh cages around all our trees. It's no 100% guarantee, but if they discourage AT ALL - it's a win. We're lucky to have MILES of oak trees, so the acorns take the top spot of their menu once they start falling. That helps. We also planted 75+ "newer" apple & crab trees in addition to the older ones we already had, so hopefully we "outplant" them.