Electric Fences for Bears: IGBC's Published Designs & Certified Products

What the IGBC Publishes About Bear-Proof Electric Fences

The Interagency Grizzly Bear Committee (IGBC) publishes a "Bear-Resistant Products" document, which also lists certified trash cans and coolers and has an electric fencing section. It recommends electric fence designs it describes as proven effective at deterring grizzlies, as an option for securing attractants where grizzlies live. It describes two designs:

• A longer-term design for securing livestock, fruit trees, compost piles, chicken coops, and other attractants on private land, and for outfitter camps. The IGBC says its seven-strand fence suits permitted base outfitter camps and the area around beehives, orchards, or chicken coops on private land.
• A portable design for recreating in bear country, securing attractants and campsites, or any time a temporary way to secure attractants is needed. The IGBC tells readers to check with the land management authority for the area about its specific food storage rules.

Note the title the IGBC gives the section: electric fencing to deter grizzly bears. BearWise's general guidance for bear fences, covered further down, gives different numbers.

IGBC Permanent and Semi-Permanent Electric Fence Specifications (Table 1)

This is the IGBC's summary of recommended specifications for fences that stay in place for a longer period, such as around beehives, orchards, or chicken coops on private land. The IGBC prints these as minimums or maximums, as labeled in each row.

IGBC Portable Electric Fence Specifications (Table 2)

The IGBC calls portable electric fences an effective method of temporary food storage in grizzly bear country and says Table 2 gives the minimum specifications needed to deter grizzlies. It adds that these specifications may be updated as more portable fences are tested where grizzlies live.

IGBC-Certified Portable Electric Fencing Products (Table 3)

The IGBC says the products in Table 3 meet its minimum requirements for portable electric fences. Fences must be built to the Table 2 specifications and must be working properly to meet food storage rules in areas where portable electric fences are allowed. The IGBC adds that this does not mean the products satisfy food storage rules on all public lands, so check with the land management authority for the area.

Two more things to know. First, there are only three products, and all three are portable. The list we read includes no permanent fence product; for the permanent fence the IGBC publishes a design (Table 1). Second, all three listings point to the same Missoula Technology and Development Center publication (Pub# 0723-2305 MTDC), the U.S. Forest Service document on portable mesh electric fence systems. For other IGBC-certified gear such as trash cans and coolers, see our full IGBC certified products list.

Why Electric Bear Fences Fail: The IGBC's Caution List

The IGBC says these are common reasons an electric fence fails:

• Forgetting to turn the fence on at night.
• Grounding it incorrectly.
• Not clearing weeds, shrubs, or trees, so they short out the fence.
• Not fully charging the batteries.
• Letting the energizer get jarred or wet, which raises the chance of internal damage such as broken wiring or a faulty on/off switch.

To confirm the fence is working, the IGBC says to measure the voltage in the fence with a voltage tester, and notes that economical, lightweight testers are available. That matches the "voltmeter required" line in both spec tables. The IGBC also points readers to two U.S. Forest Service Missoula Technology and Development Center publications for setup recommendations: "Northern Continental Divide Electric Fence System" (Pub# 9923-2321) and "Portable Mesh Electric Fence System" (Pub# 0723-2305).

How to Build an Electric Fence for Bears: BearWise Basics

BearWise, the program of the Association of Fish & Wildlife Agencies, publishes a plain-language guide to building an electric bear fence (it also publishes a two-page Bulletin #3, "Electric Fences Keep Bears Out"). Here is what its web guide says. These are general figures for bear fences, and they differ from the IGBC's grizzly tables above.

We do not know why the figures differ and will not guess; the two sources are written for different audiences. If you are in grizzly country, the IGBC's tables are the ones its own certification uses. Either way, your state wildlife agency can tell you what it recommends locally.

Energizer

BearWise says plug-in (AC) energizers are the most dependable and powerful, while solar and 12-volt battery units suit portable or remote setups. Keep the energizer out of a bear's reach; a common approach is to put it inside the fence with a cutoff switch outside. BearWise says to calculate the total length of wire, not just the perimeter (its example: a 100-foot perimeter with five wires is 500 feet of wire), and that energized gates count too.

Wire, posts, and insulators

BearWise recommends metal wire or polywire. It warns that polytape can flatten against a bear's coat and fail to make contact. Metal T-posts are the most common choice, though wood, plastic, or fiberglass also work, and plastic insulators keep the wire from touching a post and grounding out. Electric net fencing is described as an acceptable temporary solution until a permanent system is built.

Grounding

Grounding completes the circuit so that whatever touches the fence gets shocked. BearWise says to drive a galvanized steel ground rod about six feet deep, or at an angle, and to use more than one rod if you cannot reach that depth or the soil is dry. In dry soil, sand, or gravel it describes two options: an all-hot (positive) system with a separate grounded apron, or a positive/negative system where the top and lowest wires are hot. The apron is a 3-foot-wide strip of chicken wire or hog panel laid in front of the fence that a bear steps on to become grounded; it must not be attached to the fence.

Maintenance

BearWise says to walk the fence every few days, keep vegetation low (wet plants touching the wire can ground it out and drain solar batteries faster), test the voltage often with a fence tester, and inspect wires and insulators at least once a year. It says clicking can mean energy is arcing out, often from a broken wire or a loose wire touching something. It also warns that bears test fences for gaps over, under, and through, and gives an example of a bear getting under a fence whose lowest wire was too high and whose soil was too dry for good grounding. Its summary: do not wait for a break-in to discover a problem.

BearWise also says electric fences are safe for children, pets, and animals, and that a shock may hurt but will not harm. The IGBC's portable specification requires at least one readable placard warning that the fence is electrified, and the Connecticut DEEP page on electric mats advises posting warning signs near anything energized.

Garden Fence, Orchard, Chicken Coop, and Beehive: What the Agencies Say

BearWise lists garbage, compost, chickens and small livestock, beehives, fruit trees and edible gardens, and buildings such as cabins among the things electric fencing can protect. The North Carolina Wildlife Resources Commission says properly installed electrified wire is the most effective non-lethal tool for keeping bears away from things like small livestock, beehives, and compost, and that standard 4- or 6-foot fences do not work well because bears can climb them. Here is what we found for each use.

Garden fence and orchard

BearWise says a small to medium garden can be fenced the same way as a chicken yard. For individual fruit trees and small orchards it suggests a portable electric fence that goes up before the fruit ripens and is stored afterward. The IGBC's longer-term seven-strand design is described as suitable for orchards on private land in grizzly country.

Chicken coop

BearWise calls a properly built, installed, and maintained electric fence the most fool-proof, powerful, and long-lasting bear deterrent available for chickens and small livestock. North Carolina says standard coop, pen, and barn designs often cannot keep out a determined bear. We found no certification for coop fencing: the only electric fence products on the IGBC list are the three portable ones above. For more, see our bear-proof chicken coop guide.

Beehives

BearWise says to group the hives together and surround them with an electric fence, which it calls the most bear-resistant solution, and notes that portable and solar-powered fences are available. It also says hives placed at least 300 feet from forest or other cover are much less attractive to bears, even though beekeepers often like forest edges. For more, see our bear-proof beehives guide.

Trash cans and doors

BearWise says electrified gates can guard bear-resistant trash containers. The North Carolina Wildlife Resources Commission and Connecticut DEEP also describe electrified "unwelcome mats" in front of doors, windows, and entryways: they shock a bear's paws, people in standard rubber-soled shoes are not shocked, and they can be switched off when needed. Connecticut gives an ideal energizer output of 0.5 to 1.0 joules for mats. Mats are a different product from a perimeter fence and are not on the IGBC list. See also our guide to feeders, coops, beehives, and compost.

Before You Build: Local Rules and Limits

• Check local rules. The North Carolina Wildlife Resources Commission and BearWise both say to check with your HOA, community, or county before installing electrified wire, mats, or fencing.
• Ask your state agency. BearWise says some states offer design and installation help or cost-offset programs, and suggests contacting your state wildlife agency for setup or troubleshooting.
• A fence does not replace sanitation. The IGBC says the electric fence designs and products in its document are not meant to replace general bear safety guidelines for keeping bears away from tents and sleeping areas. See our guide to keeping bears away from your house for what agencies say beyond fences.
• Public land is different. The IGBC says its certified portable fences do not automatically satisfy food storage rules everywhere on public land, so check with the land manager before you rely on one.
• No guarantee. Certification does not mean a bear will never get through, and BearWise says bears test fences for weak spots. Treat a fence as one layer along with securing attractants. For certified trash storage, see our bear-proof trash cans and enclosures pages, and how we verify certification.

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