If the bear (s) that got your hives survives winter it "will come back." Bears have good memories and "LOVE" bee larva in the Spring. I use solar electric fencers and so far, so good. I have friends who aren't so lucky, having repeated problems with a bee loving bear, who has destroyed his eight foot chain link fence (latest attempt) to get to his hives.
His next step will be the organic method of control

called filling the freezer.
thomas