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.