Electric Strained-Wire Fences - Alternatives to Snares
Setting snares for rabbits is largely a waste of time for pest control. In many situations, electric fencing can be more cost effective than control methods that have to be undertaken year after year. The two main types of electric fencing are electric netting and electic multi-strand wire systems. When correctly erected and maintained, they can reduce rabbit numbers on protected fields by 85-90%.
Electric Strained-Wire Fences
There are two types of electric fence in common use: netting and strained-wire. Both have been shown to be as effective as wire-netting fences.
Electric strained-wire systems consist of seven parallel electrified conducting wires (7-strand, 16 gauge medium tensile mild steel) at heights of 5, 10, 15, 20, 25, 30, and 40 cm (2, 4, 6, 8, 10, 12 and 16”) above the ground. The lowest wire is earthed and the remaining six are live (a small length of wire should be wound around each of the top six wires to electrically connect them). Adjustable plastic insulators supported on metal stakes hold the wires. The stakes can be placed up to 7m apart (about 8 yards), although ground undulations may dictate closer spacing. Where the fence line bends, anchor posts replace the normal metal stakes. The whole system is tensioned at a reel post placed at the end of the fence.
Both electric fence types must be powered by an energiser capable of producing an output of at least 1 joule when measured into a 500-ohm resistance. Most mains-operated energisers, and the more powerful battery-powered units, have this capability. Batteries should be changed regularly (a fully charged 70 Ah battery will need to be changed every 2-3 weeks). A wide range of energisers is available and users are advised to discuss specific requirements with their supplier. To effectively deter rabbits, it is important to maintain a minimum of 2.5 kV throughout the fence-line. A good earthing system is essential to achieve this. Ideally, as for wire-netting fences, electric fences should be erected to surround fully the area to be protected. If this is not practical a strip fence, which extends at least 150m beyond either end of the problem area, may be used. Prior to erection, a 450- 600mm (1'6"- 2') wide strip should be mown along the fence line or the vegetation killed off using an approved herbicide. This ensures that the conducting wires are kept clear of vegetation that would otherwise short-circuit the system thereby draining power and reducing effectiveness. The electric netting fence should be checked regularly as there have been reports of hedgehogs getting caught, so be aware of this and consider its use only if other fencing methods are impractical.
Both electric fence types have a useful life of about ten years. Electric fencing is cheaper to purchase and erect than wire-netting.