Fascinating behaviour - it makes me wonder about whether there's such a thing as natural altruism. The bear has apples and carrots and stuff in the cage so there's no need to eat raw wet crow (a choice I would agree with, incidentally). But I would have associated that kind of behaviour with gregarious animals not with solitary creatures. On the other hand, the bear will have very few outlets for its hunting instincts.
On a related note, I saw a crow skimming the surface of a pond earlier this year and taking food (bread?) away from the ducks. Somewhat perilous behaviour. No rescue bears around either. Does anyone know whether feeding like this is common in crows. (Actually, I get really confused trying to identify crows, jackdaws, rooks, etc, so I just call them crows.)