Bears and the Bees

 

One of our members recently had a bear get into his hives. He was able to salvage one of his 3 hives but the only way to keep a returning bear from finishing the job would be to relocate that hive to a bear free location. That location was another member’s house which was not only a very nice thing to do but is one of the benefits to membership. I realized I knew nothing about bear defenses since I live on a smallish island that has never had a bear on it. I began to research bear proofing your apiary and although I still have zero practical experience, I at least have a few ideas. If you have bear experience and you see something in this article that should be corrected, or an omission or opportunity for improvement, then let me know in an email and I will update next month.

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The first thing you need to know is that once a bear finds your hives they will return. Preventative measures taken after that first encounter may not work unless it includes moving the bear to your freezer or erecting awfully expensive barriers. An electric fence is a training device that must be used before they have tasted your hives.

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Since bears are especially fond of larval bees and honey, they will actively seek out hives in their home range. Beehives should be located as far as possible from timber and brush providing bears with cover and travel routes. Honey crops should be harvested as soon as possible after the nectar flow to reduce the attractiveness of hives to bears.

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Electric fencing has been shown to be almost 100 per cent effective in deterring bear damage.

 

Electric fences have three main parts. When used properly all three components create an open circuit, which closes when touched by a bear.

1. An electrical device called an energizer (charger) pushes and regulates power through the wires of the fence.

2. The wires of the fence carry the electrical charge. This is the "hot" part of system.

3. The grounding rod is a conductive metal rod driven into the ground. To be effective as a deterrent, an electric fence must be properly grounded.

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A Positive (Hot) fence works well on our damp, conductive soils. All the horizontal fence wires are connected to the positive terminal of your energizer and a grounding rod is connected to the ground terminal of the energizer.

 

ENERGIZER

Where standard household power is available, energizers that plug into a 110V AC outlet are preferred. Where standard household power is not readily available, energizers powered by an integrated solar panel, or by a battery, are popular. Whenever possible, use an energizer putting out at least of 0.7 joules of energy. (Note that some manufacturers list "stored energy" rather than output energy. In that case, use an energizer with at least 1.0 stored joules.) Energizers should provide 40 – 45 shocks per minute. Voltage at the fence should be 6000 – 7000 volts. High impedance energizers are not recommended; these energizers may also be labeled as continuous current, weed burner or weed chopper. These long duration, continuous current pulses can create a spark that can produce enough heat to set fire to vegetation. Only low impedance energizers are recommended for deterring bears. Low impedance energizers have pulses that are short in duration, but higher in energy. Low impedance pulses are so short, less than 3/10,000 of a second, that a spark should not produce enough heat to start a fire. This short duration pulse also allows people and animals time to move away from a shock safely.

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Grounding System

Adequate grounding is an important component in the function of all electrified fencing. Without adequate grounding, an electrified fence will be unable to deliver an appropriate shock to an animal; electricity must be able to easily flow from the soil to the grounding rod, back to the energizer, for an animal to receive an adequate shock. For adequate grounding, all electrified fences will need a minimum of 3 to 6 feet of grounding rod per 1 Joule of stored energy from your energizer. However, you cannot create too much grounding in your fencing design. Grounding rods should be at least ½” in diameter and made of galvanized steel. Copper grounding rods are not recommended for electrified fencing as they can cause electrolysis and eventually corrode connections. Make sure that your ground rods are as far as possible from utility connections and water pipes. Grounding rods should be driven deeply into the ground near the energizer. The standard length of galvanized steel grounding rods are 6-8 feet and, if possible, a ground rod should be driven into the ground nearly its entire length.

 

CONDUCTORS

A minimum of 3 horizontal fence wires (5 is better) with the lowest wire 8-10" above the ground and the highest wire 40" above the ground.

 

a. Solid aluminum wire is excellent for permanent fences; it conducts electricity well and may have the best durability and life span in many climates. 14 gauge is fine for most small apiaries.

b. Galvanized steel wire, often used in drier climates, is not recommended in wetter climates, as it may rust within a few years (rust is a poor conductor).

c. Polywire and polytape – both made of plastic threads with conductive metal threads woven in – are popular choices, especially for temporary fencing. Polywire or polytape with stainless steel conductive threads are suitable for short distances such as a small apiary. Because the plastic degrades with exposure to UV radiation, polywire and polytape have a life span of about five years.

i. Polywire with six or more conductive threads is preferable to polywire with only three.

ii. Polytape has the advantage of being more visible than polywire; however, it is more susceptible to wind or wet snow.

d. To connect energizers to fences, and to connect multiple sections of fencing together, use 10-14-gauge insulated wire specifically designed for electrified fences. This type of wire may also be called insulated underground wire and is rated for 20,000 volts. Do not use household or industrial wire as they are rated for less than 1,000 volts and are not appropriate for an electrified fencing system.

e. Wires are kept taut by fence strainers that can be periodically tightened.

 

FENCE POSTS

A fence post every 7-10 feet is recommended.

a. Wooden fence posts and metal T-posts for permanent installations.

b. Plastic "step-in" posts for temporary fences; no insulators are necessary.

 

INSULATORS AND GATE HANDLES

Get Insulators that are appropriate for the type of posts being used and for the type of gate you will be using. Your gate needs to be energized or your bear will find this weak point.

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FENCE TESTER

You must have a way to check that every wire on your fence is working. The energizer may be on and blinking but a wire can still have a short, compromising your fence.

a. A multi-light fence tester has 5-8 lights that blink to indicate approximate voltage.

b. Voltmeters can provide precise information about how your fence is functioning. Be sure to use a voltmeter designed for electric fence voltages, which can be 7,000 volts or more.

 

OTHER

Bait the center hot wire fall and spring, at a minimum. Bait need not be fresh all the time. This step is crucial. Failure to bait the fence is probably the greatest cause of fence failure. The bears need to be trained to avoid the fence.

 

Set your hives back a good 4’ from the fence. Big bears have long arms!

 

Beekeepers are thrifty but sometimes we can be “penny wise and pound foolish.” A good fence can cost several hundred dollars. How much did you spend on your bees and equipment? One night with a hungry bear can wipe out all your efforts and your hard-earned money. The fence will do its job for years and years to come. A well-constructed fence protects your investment in your bees and your equipment. http://fwp.mt.gov/fishAndWildlife/livingWithWildlife/beBearAware/bearAwareTools.html https://www.easternapiculture.org/addons/2013/Simone/BearFence.pdf http://www.adfg.alaska.gov/index.cfm?adfg=livingwithbears.bearfences&tab=supplies https://carolinahoneybees.com/electric-fence-for-bears/