Bear fence?

[DirtyDusty]

I noticed quite a few post on here talking about bear fences used around there camps. Is this pretty common? How common are bear encounters during mid to late October in CO?

 

[rayporter]

in 32 years i have seen one bear. the south end of a north bound bear.

 

[ndbwhunter]

This won't answer your question, but here is my take on the bear fences. I was researching this topic a while back and spoke with a few bear biologists, and energizer manufacturers. Their concensus was that the energizers sold with the UDAP and Counter Assault kits (AN20 or AN90) are virtually worthless. Sure, they are attractive to backpack hunters because of the weight, but they simply can't produce the power needed to effectively deter a bear. Under ideal conditions (wet ground) they may get a good jolt, but most of us wouldn't camp in an area like this anyways.

If weight isn't an issue, and you are concerned about bears, then you could definitely bring an energizer and battery that would produce enough output to deter any bear. If one of the backpacker friendly kits would give you piece of mind and keep you in the woods, then go for it. I simply couldn't justify the cost or weight knowing that my sidearm/spray would likely give me better protection in camp.

 

[GotDraw?]

I built my own system after looking at all available systems. Give me a couple days and I can probably post a list of components/suppliers to the Make Your Own Gear section. Total cost was about $130/$140 or so if I recall properly. System pricing was a deal compared to buying a ready made system with carbon poles.

My system is super light, using a 4D cell Speedrite AN90 charger that puts out 1.2 joules. This very backpackable system weighs 2.8 lb (total weight for *everything* except batteries), including storage bag, charger, ground rod, six 40" poles (re-purposed used carbon fiber arrow shafts), ground rod, guy lines to support the poles, poly wire tensioners and enough light weight polywire to surround a large 6 man tent that has 2 massive vestibules (including the area encompassed by the guy lines). My system currently protects about a 30'x20' area, but I could use more or less wire if I wished. The unit will run for about 2 weeks+ on 4D cells.

I did far too much research on this topic, reading a number of actual studies (not suppositions) before building one. Including a long term study by the National Outdoor Leadership School. From what I can tell, the fences work. I read one report where a large carcass was placed inside a large outdoor grizzly enclosure with multiple grizzlies and despite the fact that the bears wanted it bad, they did not get to it. That system used the less powerful, but lighter AN20 .04 joule charger (2 D cell). These systems seem to work because 1) bears generally ask questions with their noses or mouths, so a 6K volt hit to the tongue or nose gets their attention. 2) They don't understand electricity, but do understand pain. 3) You will only enclose a small area with the fence, so the resistance load from the relatively short length of polywire will not be nearly as high as it would be if you tried to enclose an entire pasture nor will the ground rod need to be as deep as needed to cover many acres.

**Typically, if you wanted to enclose a large grazing area, you need a high output charger because you have a longer run of wire (more ohms of resistance) and you know that grass will grow up to the bottom wire and short the system, so they system has to be able to burn off the grass. Our coverage area requirements can be measured in sq feet, not acres and we can pull the grass tops off to keep the fence clear.

**If you plan to camp on a gravel bar, then the system must be built differently. Gravel provides no ground. The fence component will need to be an alternate positive/negative wire grid pattern that looks sort of like hog wire. This material is very available and is often used for goats. It does weigh much more though. That said, it weighs much less than the anxiety of sleeping on said gravel bar in brown bear country without a fence.

JL

 

[Manosteel]

Si would be interested in you providing a list and how to DIY on this project.