Bears are a vexing problem here too. A simple solution is to remove all
edibles from the area and place a radio near the hive, perhaps under a
second hive body. play it all night very low, just so you can hear it about
15 feet away.
 
Here on Vancouver Island bears are a major issue, and a wide variety of anti
bear defences are used. From electric fences to urine marking posts to bear
cages for the hives. All work to some extent but the bears don't all
cooperate all the time.