Greetings from Black Bear Country!
Spring 2011. After 5 visits in over 3 weeks a big (over 450lbs) old (grey whiskers) boar (boy bear) wiped out the last remains of our beeyard. Fortunately we only had 3 colonies, but one was a 3 year survivor colony. Caught him in the act one night and only a shotgun blast over his head from 10-15 ' away caused him to leave....the same way he came....right through my SIX strands of electric fence.
The Wildlife Manager
who finally trapped this old guy said "he'd likely done this before and thus had 'no fear' of electric fences." I can only agree. I mean "really" if a Bear can take several thousand stings to his head I doubt an electric fence will 'always' succeed. Once brood is tasted nothing else matters to a determined Bear.
Immediately following that episode we bought 4 of those NITEGUARD lites seen in all the BEEK mags for $19.99. We've since had several bear in the area, in fact our nearest neighbor a 1/4 mile down the road lost a 200lb alpaca to another Male Bear during the 2012 mating season (males can get pretty unpredictable that time of year) and we caught one in our garbage, not 100yards from our beeyard, but the lights worked and continue to.......so far. I should say that 2011 was the first time we had Bear disturb our bees in almost 10 years, in Bear Country. When we had pigs for several years when the kids were still home, they'd (Bear) bother them sometimes but nothing like the damage done to our bees.
I'm buying more Niteguard lites before Spring comes and recommend them to anyone keeping bees when in Bear Country.