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Electric Barrier Fencing for Primates

by Arthur Hunt


Why electric barrier fencing is ideal for primates to live in.

In the past it was considered impossible to contain primates, unless confined in cages. Alternatives were too expensive to build and usually consisted of high unscalable walls, motes or panes of smooth surfaced material to prevent primates from climbing out of their enclosures. This has meant that primates had to be housed in small and expensive caged areas that had to be artificially enriched.

The advent of electric fencing provided the means to cheaply erect fences that could enclose large areas and allow for a more naturally enriched environment.

(I took a piece of natural bush and enclosed that. In the centre is a gigantic tree and equates into a total area of approximately 7,500 cubic metres of natural habitat for them.)

That was five years ago and during this time I have done much research and testing of various configurations etc., and have come to the conclusion that electric fencing works best if you first teach the primate that a particular configuration of wires is a no-no and they soon learn not to touch them and, once this happens they ignore the electric section. I also noted that if a monkey received a second shock it reinforced their fear.

(In the beginning of the forty two monkeys introduced only three monkeys were fascinated with the wires and spent long periods of time examining them, each strayed too close and were zapped and received a second shock, they now never go near the wires.)

We also switched off the electrics for a period of three months and they never noticed.

(But remember some animals can detect when an electric fence is on and off, so first experiment to see of they are able to detect this. Lions for example can detect it immediately, and elephants as well.)

Before I introduce a monkey into an electrified enclosure, I first place them into a learning enclosure so that they can get their first shock. (It is very important to do this so that they get to learn about the electrics first and this must be done under strict supervision.) Once they have been shocked, they do not try to escape by negotiating the electric section and stay clear of them. (This is most important because if a monkey is chased or dominated and tries to get away it then knows that it cannot negotiate the electrics and thus plans its escape within the confines of the enclosure.) A monkey that does not know that the wires can shock will attempt to climb out of the enclosure and they usually succeed in doing so.

FATALITIES

In the past we have heard that primates get tangled in the wires and are shocked to death, this only happens when the primate does not know about the electrics, like in the case of a baby that is born in the enclosure. When they become mobile they do attempt to climb the fence and come into contact with the electrified section. It is vital to train the babies as well, and this will prevent any deaths by electrocution.

(The charge generated is a static one, similar to that produced by the spark plug in your car. It is intermittent and repels rather than attracts. However, the charge that the energiser produces is approx. 8,500 volts and can kill if exposed to prolonged shocks. The problem is that some primates are knocked unconscious by this high voltage ((even us humans)) and they can die when they become entangled. when there are babies in the enclosure i run the system on half the voltage as well.)

ELECTRIC BARRIER ENCLOSURE

The enclosure employs the latest design in electric fencing to hold vervet monkeys. Five years of testing has gone into the current configuration.

The fence is made up of two parts, the lower is fencing and the upper is the electrified section. (The overall height of the fence will depend on the height that a monkey can jump from a free standing position. Remember some species of primates can jump very high when they have a platform to propel themselves from. Trees situated near to the fence must be removed and a large enough space must be cleared. These two factors must be taken into consideration.)

After completing jump tests i settled on a height of 2 metres even though the results of these tests showed that a fully grown vervet cannot jump out of a fence that is 1.7 metre in height.

Lower part: is 2mmx50mmx500mm or 2mmx75x75mmx500mm diamond mesh. (I use this wire because it's the cheapest. If you are going to have babies in the enclosure then you may need to look at a smaller hole than 75x75.)

Upper part: is electrified strands of 2mm wire lightly galvanised with an in-line wire tensioner, the wires are alternated live and earth.

Electrics: MEPS energiser with battery back up system, delivering an 8,500 volt static charge once ever second.

Reinforcement and stabilization of electrified section: black or green UV resistant twine is woven at one metre intervals into the design to prevent separation of electrified wires and thus forms a barrier.

Insulators: are made from UV resistant PVC irrigation pipe and U staples.

Uprights: are placed every 10 metres.

Corner uprights: are stabilised in three directions.

ELECTRIC ENCLOSURES MATERIAL REQUIREMENTS

Corner posts: 2,5mx150mm. Posts are thick treated wood poles. These posts must be stabilized to take the strain in two directions. They are planted and concreted in holes 500mm deep Wood pole uprights. These poles can be thin poles up to 50/100mm in diameter and are place every ten metres apart.

Lower Fencing Section. Diamond mesh 75mmx75mmx500mm or 50mmx50mmx500mmwide 2mm thick wire fence. The fence is buried in a trench to the depth of 150mm. This is to prevent digging under the fence. It also allows for clearing of vegetation that could interfere with the electrics.

Bloudraad or 3.5mm or 4.00mm gage galvanised wire. One strand is secured 500mm from the ground to which the fencing is attached and forms the line for the electric section to follow. Another strand is secured at ground level.

Upper Electrified section. Ten to 12 strands of 2mm lightly galvanised wire is secured at intervals of 90mm for the first seven then at 100mm intervals. Each strand completes a full circuit. (Depending on the size of the primate these wires can be placed closer for smaller ones and further apart for bigger ones.)

MEPS insulated strainers. Strainers are placed at each corner post.

PVC UV resistant irrigation pipe Insulators. 80mm lengths. Pipes/insulators are first threaded onto the wire then nailed with U pins onto the wood uprights.

MEPS in-line wire tensioners. One tensioner per strand of wire.

MEPS Energiser model 125. One (1) needed. Connecting cable from energiser to fence. Large wire U pins.

Black UV resistant polyester twine. Twine is woven at one metre intervals through the wires of the electrical section in a special manner to stabilise the wires. It is very important that the twine is looped around each wire a number of times so that the wire is held firmly and stays in place. This is a very important feature of the fence as it prevents the primate from pulling or pushing the wires apart.

I know that anyone who uses this method will get a lot of satisfaction when you release your monkeys/primates into one of these enclosures.

Arthur Hunt
Project Leader/Rehabilitator
Vervet Monkey Foundation
Rehabilitation Centre, Orphanage, and Sanctuary
Tzaneen - Northern Province