Prevent Damage to Beehives with an Energized Fence

A beekeeper's guide to developing a cost-effective, energized fence to protect beehives from black bears.

electrical grounding system, 3. • Energizers may be attached to proper wire and post spacing. and the outside of a hive or hidden each year, the Minne­ 4, monitoring of fence status with in a false hive. Some D-cell sota Department of a vo lt meter. chargers may be hung directly Natural Resou rces from the fence wire. ~E(D NR) receives complaints 1. Energizer from beekeepers whose bee­ • A high voltage, low impedance • Batteries must be insulated hives have been damaged by energizer delivers a short from the ground. black bear!.. Kill ing bears that (.0003 secon d), painful, but cause damage does not pro­ safe shock to bears. The short • The fence must always be tect the beekeeper from pulse will not set fire to grass energized. The energizer and financial loss nor does it contacting the wires, nor will it grounding system should be prevent subsequent losses injure humans or animal s. installed and operational prior from other bears. By contrast, to installing posts and wire. All energized fence designs have fence wires should be ener· been tested and proven effec­ gized. tive in preventing bear damage to beehives. Energized fences • Coated underground cable should be considered for may be buried as a lead out protection of all beehives in wire from the energizer to the areas that have the potential fence and from the energizer for bear damage. to the ground rods.

• Remember, the shocking power of the fence deters the Fence Design bear. The posts and wires are A basic fence design is the delivery system: it is not a shown in the illustration on physical barrier, and will not page 3. The four critical com­ • Energizers may be powered by be effective unless It is con­ ponents to an effective ener· a 6 or 12·volt battery, D-cell stantlyenergized. gized fence are: I. a high alkaline batteries, or II O·volt AC current. voltage. low impedance ener­ 2. Grounding gizer capable of delivering a • Use a minimum of three 6 foot • Deep cycle marine or gell cell minimum of 4,000 volts under ground rods. Additional or batteries are recommended all conditions, 2. an adequate longer ground rods may be for 12-volt energizers. necessary on sandy soils or treated wood or 7 to B-foot Maintenance during dry conditions. Ground long, 1 1/ 4-inch diameter Monitor voltage weekly. rods should be driven into the fiberglass rod. Place the wide Charge or change batteries as ground so that approximately end of the wooden post Into required. usually every 3 to 4 3 inches remain above the the ground. Angle corner pOSts weeks. Some energizers may surface to attach the cable slightly away from the corner. be equipped with solar panels from the energizer. In light or sandy Sail, longer to recharge the battery. Veg­ corner posts or an anchor post etation must not contact the • Ground rods should be galva­ may be necessary. You will fence. Mowing, weed whip­ nized steel; avoid copper. need about 4 feet of post ping. herbicides or soil ster­ above the ground. ilants may be used to control • Ground rods should be placed vegetation on an 1 8-inch wide 10 feet apart. • Use high density plastic or strip under the fence. Apply porcelain insulators with herbicides according to label 3. Wire and Posts wooden corner posts. Avoid instructions. • Fiberglass, plastic, or wooden wraparound and tube insula­ Fences around beeyards posts with insulators are tors. that have hives only in the recommended. Steel posts with summer should be taken down insulators may leak voltage 4. Voltmeter dUTIng winter months to and should not be used. • A voltmeter is critical for reduce wear. Corner posts may monitoring voltage and for be left in the ground over • Seventeen gauge, smooth steel trouble shooting. Voltmeters winter. Ear tags used by cattle wire, poly wire or light gauge are available from energized farmers to control face flies steel cable may be used. Many fence manufaclUrers. may be placed in the energizer growers prefer steel cable. Poly to reduce ant nest building. wire is not as durable as steel With proper care, fences wire or cable. Do not use should last 10 or more years. barbed wire. Other Considerations Baiting the wire is not gener­ For further details, trouble· • Wire tension is adjusted by ally recommended. Baiting may shooting information. or if you hand-pulling to tighten, and serve as an attractant where bears have questions contact your held with knots on the end. have not been a problem. local DNR wildlife manager. Spring-type gate handles also Spring loaded gate handles serve to maintain tension. Use may serve as the entrance to the small tension springs with beeyard. The width of the gate Safety light gauge steel cable. may be customized to each Safety is a primary concern operator's needs. Some operators when using energized fenCing • Place in-line posts 10 feet may prefer more than one gate. As systems. The beekeeper is apart. It is important to main· an alternative, all fence wires may responsible for protecting tain the wire spacing shown in be attached to a single fiberglass others from injury. Use ener­ the illustration on page 3. or plastic rod so all wires may be gized fence warning signs and opened simultaneously. an unaltered energizer, listed • If skunks are an additional Locate hives at least 3 feet with a qualified electrical problem, an extra energized inside the wires. If hives are close testing laboratory, to protect wire may be added 4 inches to the wire, a bear may reach yourself and others. Always above the ground. through and tip the hive over. follow the manufacturer safety Locate the hives away from recommendations. • Corner posts may be 8·foot over hanging trees and large long, 4·inch diameter, pressure branches. Illustration of Energized Fence- Modified New York Design (not to scale)

Porcelain InSulators are ·wlre tied" 'P' Springs are used to matlnain to the corner posts. l.,....\-. wire tension when uSing galvan­

cable.

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PVC pipe fits Slake over stake. " Wire loop on I pOst holds PVC pipe -----\Jtud,ods--- Energizer and grounding ,n place. system location art determined by Slit conditions. Shown in front Spring type gale handles for damy only. They can can also be used for be hidden in a modified Individual wires. hive,

Materials List for Energized Fence - Modified New York Design (See illu s tra tion above) Materials list and price estimate (2003) for a 20' by 30' energized enclosure to exclude bear:

Quantity Sou rce Description Unit Cost Total Cos t I G Energizer (at least.7 Joule) $1 \ 0.00 Sl10.00 3 G 6' galvanized ground rods with clamps 10.00 30.00 G Digital voltmeter 60.00 60.00 4 F 8' x 4" round treated posts 7.00 28.00 1/2 Ib, F Galvanized fence staples 0.50 0.50 125' F 12.5 or 14 gauge steel wire to attach porcelain Ins ulators to wood posts 4.00 24 G Porcelain doughnut insulators 0.30 7.20 As needed G 12.5 gauge insulated underground cable (6S') 24.00 24.00 8 F 3/8" x 48" fiberrod posts 0.80 4.80 48 F 3/8" post clips 0,25 9.00 4 G Fence warning signs 2.00 8.00 2 G Poly wire (655' roll) 16.00 32.00 F 3/4" x 36" stake 4,00 4.00 F , · 1/4" x 4" schedule 80 pvc 4,00 4.00 G MaxiShock steel cable (optional wire) 46.00 46 .00' 6 G "f>" springs (necessary with "Maxi5hock") 3,20 19.20'

Source: G· En e rgized fence suppli er F- Farm supply store Estimated total cos t S32S.50 ·optional wire and springs were not figured in total cost For more information call: Fence Material Sources (651) 296·61 57 (Metro Area) 1·888·646·6367 (MN TolI·free) UAP Great Lakes Kencove Farm Fence Supplies Telecommunication Device for the Deaf POBox 143 344 Kendall Road (65 I) 296·5484 (Metro Area) 101 South Chestnut Blairsville, PA 15717·8707 1·800·657·3929 (MN TolI·free) laCresenl. MN 5S947 (BOO) 536·2683 (SOl) 895·21 03 www,kencQve,(oro () CoPyri9ht 2003, State of Minnesota, Department of Natural Resources. Shepard's Hill Farm Midwest Fence Dave Deutschlander 5201 St. Paul Rd. Equal opportunity to participate In and benefit from Rt. 4, Box 43 Medford, MN 55049 programs of the Minnesota Department of Natural Pine City, MN 55063 (507)4$1-8657 Resources is available to all individuals regardless of (320) 629·2 744 race, color, creed, religion, national origin, sex, Eikmeier livestock Systems marital status, status with regard to public assis· K·Fence Systems 48737 237th St. tance, age, sexual orientation or disability, Discrimi· RI. 1 Box 195 Pipestone, MN 56164 nation inquiries should be sent to' MN/DNR, 500 Zumbro Falls, MN 55991 (605) 997·2022 Lafayette Road, St. Paul, MN 55155·4049; or the (507) 753·2943 Equal Opportunity Office, Department of the Interior, www.kfence.com Waconia Farm Supply Washington, DC 20240. 801 S. Hwy. 284 Premier I Waconia, MN 55387 This information Is available in an alternative fo rmat 2031 300th St. (9S2) 442·2126 upon request. Washington, IA 52353 (888) 741·3276 (SOD) 282·6631 www.waconjafarm.com listing of company names Is for the readers conve· www.premierisupplies.com nience and Is nOI considered comprehensive. The David Mciver State of Minnesota neither recommends nor en· 15624 340th Avenue dorses specific products or companies. Farwell, MN 56372 ft Printed on recycled paper containing a (320) 283·5776 "., minimum of 10% post·consumer waste.

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