In re: using urine to discourage bears.

What follows is my opinion, not backed up by research at all. But it would seem to me that all urine can do is notify the bear that a human is present, or has been present recently. What the bear does with that information will depend entirely on how the bear perceives humans.

If the bear has a fear of humans, or simply a mild aversion, then it will be likely to act on those feelings through avoidance. However, in the California Sierras and some other places, there are many bears who view humans as blazing beacons marking the spot where they can find lovely human food.

Further more, because a bear has an extremely acute sense of smell, and humans tend to be pretty smelly by a bear's standards, the chances are excellent that the bear will know a human is nearby, with or without using urine to alert it.

In summation, my opinion is that urine wouldn't do squat to help you avoid bears. They'll know you're there anyway and what they do about that depends on the bear, not you.