Electric Fences

ELECTRIC FENCES

Electric fences are high-cost and effective barriers installed around protected areas, farms and compounds.

When an elephant touches the fence with its highly sensitive trunk, it will receive a short, sharp shock that is enough to keep the elephant away.

The shock should be safe and will not kill the elephant.

Electric fences are physical and psychological barriers that deter elephants from individual areas while allowing them to continue moving through the landscape to access resources.

Fence success is achieved through a safe voltage, the presence of earth wires, and ensuring the live wires come into contact with the sensitive body parts of an elephant.

Groundrods

Ground wire

Live wire

Hedgehog fencing installed in Kenya © Sanyati Fencing

4 common designs of elephant - proof electric fences

1. Hedgehog/Butterfly Wiring

Short fence posts around 2-3 feet high are more difficult for elephants to push over compared to 6 feet poles.

These short fence posts are supported by what is known as ‘outriggers’, sometimes called ‘hedgehog’ or ‘butterfly’ wiring.

1.2m long electrified outrigger strands of wire are spaced 2 feet apart which point upwards at a 45-degree angle. 3 feet is too far apart and may be less effective.

This makes it more difficult for elephants to use their tusks to break the wires and knock the poles down.

The closer the outriggers are to each other, the more effective the fence.

Fences can be powered by both mains and solar-power.

Safe voltage settings lie between 6kV-9kV; most prefer 5.5kV as it is usually enough to deter an adult elephant.

Forest elephant in Ozdala-Kokoua National Park, Congo © Irene Galera

Loops in the outrigger wires

2. Vertically Hanging Electric Fences (VHEF)

PROS +

In VHEF, the hanging wires cannot be pushed or pulled by elephants even with the tusks as the end of the wires are free and have no attachments

The wires knock vertically into the elephant causing a larger body area shock than a cross wire from a typical elephant fence.

When elephants come into contact with multiple shock points, they get confused and are unable to break the fence.

2 horizontal wires are placed at a high elevation (above 15 feet) on an extending arm of an upside-down “L” shaped post.

The vertical, straight hot wires are hung downwards at 1 m intervals, in two rows in a zigzag formation that stops 4 feet above the ground.

https://www.thebetterindia.com/232462/ifs-hero-elephant-safety-fence-electric-uttarakhand-haldwaniman-animal-elephant-conflict-india-nor41/

People and livestock can still move across/under the fence if there is enough space between the wires.

It is impermeable only to elephants.

The VHEF has been installed in three locations in Sri Lanka for more than two years where the HEF was ineffective for many years.

The earth wire is shallowly buried outside the fence, where the elephant is expected to stand. This is to maximize the electric flow during the dry season.

The pole cannot be reached to push down because it is 8 feet from the hanging hot wires.

Vertical fence stopping elephants from exiting a conservancy, Kenya © Sanyati Fencing

4 feet

8 feet

3. Single/Double/Triple High-strand fence

This type of fence consists of 1 or more wires, at a height of 1.5m to 2m, that are strung from tree to tree, preferably in a straight line.

This type of fence is more cost-effective

The wirings of this fence are strong and have high tension to prevent sagging or elongation and are attached to trees using W-insulators.

Add extra horizontal strands to the fence if one is not enough.

The overall wiring has a ground-earth return system.

TOP TIP

Use combined deterrents such as motion-sensor flashing lights to increase the effectiveness of the fence and to also make the fence visible to other community members.

1 strand

Using trees may make it more difficult for elephants to push down/destroy when there are live wires attached and surrounding these trees.

This type of fencing allows livestock and people to safely pass through, preventing damage risk.

The fence can be put up quickly and also taken down between crop seasons making it very adaptable for shifting cultivation and cheaper for maintenance

2-3 strand

Single strand fence managed by farmers in Gabon © Space for Giants

5 feet

This type of fence is commonly used to border national parks and game reserves/ conservancies

Electric Game Fence

It consists of 15 or 16 high-tensile wire strands attached around the area and stands 2.5m to 3m tall.

Outriggers are attached to the wires to make them more effective against elephants.

Wildlife fences are intended to reduce human-wildlife conflict and protect and restore the land within from illegal human activities

Electric grids can be placed along a cemented patch of ground that zaps an elephant or cow foot if they try to cross it.

Why do electric fences work?

Elephants are intelligent animals and are capable of learning from unpleasant experiences

The shock an elephant receives from the fence creates a negative association with it,and they learn to avoid it in the future

A small, encircling fence around a valuable resource (e.g. farmland, a water point, or a food storage facility) has the best chance of success in reducing elephant damage and overall cost-effectiveness.

Electric fences can be solar-powered, and batteries are charged during the day to work through the night.

Communities that live adjacent to and immediately outside game fences highly benefit from protection against crop-raiding elephants.

However, it is important to note that the location of fences in relation to landscape factors, maintenance of other fences that are not electric, and proximity of fences to areas of high elephant concentration are significant determinants of fence performance in mitigating elephant crop-raiding. - Kioko et al. (2008).

Kioko, J., Muruthi, P., Omondi, P., & Chiyo, P. I. (2008). The performance of electric fences as elephant barriers in Amboseli, Kenya. South African Journal of Wildlife Research, 38(1), 52–58. https://doi.org/10.3957/0379-436938.1.52

Depending on the height of the fence, it may keep away other crop raiders such as baboons or buffalos.

Electrified ground grid, Kenya © Sanyati Fencing

1. Tsavo Trust, Smallholder 10% Fence Plan

Location: Tsavo, Kenya

The 10% Fence Plan was first designed for communities living in the Wildlife Friendly Zone of Kamungi Conservancy.

10% of each individual’s land (plots vary from 20-150 acres each) is fenced using electrified “hedgehog/porcupine fences”, widely used to mitigate human-wildlife conflict in Kenya, allowing the landowner to grow crops.

2. Rhino Ark Fencing Project around Imenti Forest

Location: Mount Kenya, Kenya

Imenti Forest hosts the highest density of elephants out of the 2,600 elephants recorded in Mt. Kenya National Park and Forest Reserve.

The galvanised fence includes a tight-lock fence to ensure that burrowing animals do not get out of the protected area.

It costs Sh3 million to fence one kilometre ($22,000). They aim to fence 450km in total.

The unfenced 90% is left accessible for other wildlife (such as Dikdiks, impala,elephants, etc) and livestock to graze.

This idea has both the marginal environment (90%) and the landowner’s subsistence needs (10%) in mind.

The success rate has been a 100% decline in crop raiding of crops grown in the fenced area.

Residents in areas neighbouring Mt Kenya Forest have benefited from the fence because the frequency at which elephants used to raid their farms has reduced

Rhino Ark employed locals from the forest to monitor the fence, to prevent anybody from accessing the forest, and animals from getting out.

157 individuals manning the electric fence are tasked with ensuring the fence has the right voltage to deter the elephants from getting out of the forest and into farms.

Read more on 10% Fence Plan – Human-Wildlife Coexistence

Read more on New fence in Imenti forest to reduce wildlife-human conflict

Maize crops protected by hedgehog electric fence © Tsavo Trust

Happy farmers supported by Tsavo Trust © Tsavo Trust

3. Cluster Farms - Northern Panhandle, EcoExist

Farmers have been encouraged to concentrate their farms into “clusters” on either side of well-established and demarked elephant corridors.

130 clustered farmers are protected by a 3-strand solar-powered electric fence costing approximately $30,000 for 12km.

Location: Botswana

Important factors to note

Due to the high cost of installation and maintenance, private sector and/or community participation is critical for the success and sustainability of electric fencing projects.

Once installed, farmers whose farms are protected must be included in maintaining the fence and ensure any incidents of breakage are recorded and fixed immediately

The cluster farms are supported with intense agricultural inputs, concentrated farming techniques and irrigation where the farmers can harvest more crops protected

The elephant corridors are left open, reducing the temptation for elephants to break into the farms while travelling to water sources

This electric fence successfully separates agricultural lands from elephant corridors.

Read more on Human-Elephant Coexistence in the Okavango Panhandle

Using combined deterrents, such as trenches or stone walls with electric fences can increase the effectiveness of keeping elephants away.

Of all reasons why electric fences fail, maintenance is the most common. A poorly maintained electric fence will fail to keep elephants out of farms and waste money, time and efforts taken into installing the fence.

Some key maintenance needed include:

Checking of batteries, energizers, wires, etc.

Clearing of vegetation (shrubs, grass, etc) from around the wires to avoid shorting.

Checking the voltage and circuit is running across the whole fence.

Immediately repairing any damage to the fence.

The type of wiring needed for electric fences depends on several factors (terrain, length of fence, etc). Some commonly used wiring includes high-tensile wires, galvanized steel or aluminium wires, etc.

Read more on Maintaining Electric Fences by WWF.

Complete 3-strand electric fence with warning signs © EcoExist Botswana

What to consider before and when an electric fence is installed

Consult with a professional electric fence installer or supplier to determine the best height and distance for your specific needs and to ensure that the fence complies with all local regulations and safety standards

Detailed manuals are available that can be used as a guide to ensure the fence is fully functional. The more slanting or rocky the ground is, the more difficult it is to install an electric fence.

Crossing water bodies (such as rivers, and streams) with electric fences is uniquely challenging and should be avoided if possible.

Falling twigs, insects and even birds can trip the circuit, causing it to lose voltage. Consider laying gravel under the fence to keep the grass down.

Get more details on how to maintain electric fences here: Paige, C. 2012. A Landowner’s Guide to Wildlife Friendly Fences, second edition. Montana Fish Wildlife & Parks.

Issues such as the voltage and earthing, the quality of maintenance, and how fencebreaking elephants are managed are more important to consider.

Powerful energisers running relatively short sections of the fence are needed (8-10 km).

Good solar batteries together with large solar panels are required to keep the circuit running continuously, especially during the rainy season.

To make sure that electricity flows safely, the fence requires strong and regular connections between the ground and wires (earth pegs) that carry electricity.

This is important whether or not an elephant accidentally touches one of the wires.

The minimum height of electric fence poles begins from 2 feet (hedgehog fences) to 7 feet tall.

The spacing of the poles varies from 8 to 12 feet. However, the poles may need to be spaced closer together in areas where the terrain is rough or the soil is soft.

8 -12 feet

2-7 feet

A long-term solution to promote human-elephant coexistence

Most electric fences put up to protect farms have shown to be highly effective in preventing crop raids by elephants. Increases crop production, families then have food stored during the dry season.

Extremely high-cost fence in both construction and maintenance.

Elephants may learn to be ‘fence-breakers’, using their tusks to easily push over fence poles so the addition of outriggers generates extra costs.

Reduction of illegal logging, livestock overgrazing and bush meat hunting by the communities in protected wildlife areas.

Wooden poles may be attacked by termites and become weak.

Fence wires may be susceptible to corrosion and loss of tension.

Expert assistance and specific tools for both construction and frequent maintenance are required.

Risk of theft of fence materials such as solar panels and fence wires may be used for snares/personal use.

Risk of community members illegally reconnecting the power to dangerous volt levels that can electrocute people and elephants.

If electric fences block important wildlife corridors, they may shift the conflict to other community lands or force elephants back into farms as there is no way through for them to use.

Elephants may learn how to short the circuit by pushing over trees or throwing branches on the fence wires.

Caution Tips

Community awareness is required so the fence is not tampered with or misused.

It is key to include the community in the fence construction to foster a sense of ownership and to ensure they monitor the fence. This will reduce the chances of power supply components being stolen.

Power supply units can be sited at homesteads which are close to the fence so that there is always somebody around to look after them.

Blocking the natural passage of elephants through corridors will force them to wander into farmlands to find an alternate route, and

“Guard houses” can be built at the power supply units to guard the power supplies.

Any fence breaks must be attended to immediately to keep the circuit running or the whole fence can easily be destroyed by elephants.

WWF manual on Electric Fences

Put up fence markers such as cloth flags on the posts and hazard signs indicating that the wires are charged and people should be aware not to trip the

Be aware that elephants can break the fence, even after receiving mild shocks.

Watch how elephants can break through electric fences: https://www.youtube.com/watch?v=-aVIIkRqXog

https://www.youtube.com/watch?v=9K97d4jSYdU

Credits and Disclaimer:

We have collected the information above from multiple sources that are sourced throughout the document. Case studies included are sourced from EcoExist, Tsavo Trust and Rhino Ark Detailed manuals can be accessed online for further guidance. To learn more and explore more on Electric Fences, see References. Some original words commonly used have been simplified for easy understanding. Save the Elephants advises caution with all the information collected and presented in this toolbox. Further research may be required before each site-specific implementation.

* Save the Elephants is not liable for any costs, damages or injuries incurred by the use of these methods or information.

The use of electricity directly from the main line without an energizer is illegal and fatal.

Even though electric fences are highly effective, it is only part of the solution to mitigate HEC.

Illustrations by Nicola Heath