Barrier or exclusion fencing is a non-lethal method commonly used to prevent fox attacks on domestic livestock and threatened wildlife species. Although fences are commonly used to protect livestock (eg poultry) from fox predation on a small backyard scale, they have only recently been used on a larger scale in Australia. This has mainly been in response to the need to protect threatened wildlife species and the availability of electric fencing materials.
Fencing can be effective, but the barrier is not absolute. A monitoring system and a management plan need to be in place to rapidly detect and control any breaches. Surplus killing (where they kill more than they can eat) by foxes that manage to breach a fence protecting endangered species can be catastrophic. Additional fox control in a buffer zone outside the enclosure can make fencing much more effective.
There are a range of fence designs that have been developed to exclude foxes. Choosing the best design depends on:
- which species are to be protected
- the area to be covered
- whether other pests are also to be excluded (eg rabbits)
- the presence of non-target animals
- maintenance resources and budget.
Features of the local environment also need to be considered, such as the topography, substrate (soil, rock etc), vegetation density, climatic conditions and geographical location.
Most fence designs are composites containing wire netting and electric wires. Wire netting (40—50 mm diameter hexagonal) stops foxes pushing through the base of the fence (30 mm diameter is needed if rabbits are to be excluded as well). Electric wires are used as added deterrents, although they are generally ineffective by themselves. Placement and spacing of wires can vary (see diagrams).
Foxes are excellent diggers, so the wire netting should be either buried at least 450 mm underground or attached to a concrete or wooden floor (in the case of a small pen). Alternatively, an apron of netting angled outwards across the ground for 300—600 mm at the base of the fence is also effective. These aprons need to be secured with weights or pegs in areas of soft substrate or water courses.
Foxes are also excellent jumpers and climbers. They can jump a standard 900 mm fence; so many designs double this height (1800 mm) using more netting or various spacings of electric wires. However, this naturally increases the cost of the fence. Standard-height fences are often used when the area can tolerate occasional fox incursions and the cost needs to be minimised.
An outward-facing overhang can also prevent animals scaling the fence. These overhangs can be floppy or rigid and incorporate electric wires as added deterrents. In smaller pens, a complete wire netting roof is also an option.
Posts and corners are often targeted by foxes and should be given special consideration. Steel posts are more difficult than timber ones for an animal to climb. Extra netting should be added at corners to discourage climbing. Weak points in netting and joins should be strengthened to prevent foxes from forcing their way through. Wire needs to be thicker than 0.9 mm, as foxes can chew through this gauge.
|Author||Invasive Animals CRC|
|Publisher||Invasive Animals CRC|
|ISBN/ISSN||PestSmart code: FXFS3|
|Region||Australia - national|
PestSmart Factsheet: Fencing for fox control [700kb PDF]