Wildlife Friendly Fencing Guidelines

The first “rule”of wildlife friendly fencing: If you really don’t need to fence, don’t.

Wildlife friendly fencing is defined as fencing which completely excludes wildlife without harm and contains no wildlife habitat, or fencing which allows harm-free passage. The type of fencing depends on the property circumstances and locations of uses. It may also depend on the amount of crop or landscape loss you can allow without considering it a serious problem, and answering the question of how much you are willing to sacrifice for wildlife.

Many people, who have not lived in the country with wildlife, tend to put up exclusion fencing around their property and frequently along their property lines. If the property contains native habitats and the fences exclude wildlife, severe impacts can occur for wildlife including loss of food, resting areas and travel corridors, as well as provide refuge for wildlife within the use area making it difficult to remove them. It is always best to completely separate uses, particularly crops or special landscaping. The guideline is to fence in only the use you wish to protect, and avoid fencing in native habitat that the animals need.

If you have to fence, the selection of fencing can be critical for wildlife, and one must consider the purpose for the fence to determine what is appropriate in any given situation.

Containment Fencing (inclusion)

is designed to keep domestic animals in, and is used for cows, horses, goats, sheep and other livestock, and for containment of pets or small children. Some of the most common fencing types for these purposes are:

1)   Simple wire strands on posts using from 1 to 6 wires, either barbed or smooth, generally from 4 to 6 feet high.

Simple wire fences can be very effective in keeping most livestock contained, and allow animal passage either over or through the wires. Small animals such as skunks, raccoons, deer fawns, and coyotes can pass under (allow 12” to 18”), and adult deer can easily walk through or jump over. A smooth bottom wire should be used to prevent scratching or puncture, and wire spacing should exceed 10 inches and be kept tight to prevent deer from catching their feet and hanging on the fence. Electric wire fences can generally use fewer wires since animals quickly learn to respect them.

2)   Graduated field fence (woven or welded wire) with barbed wire on top, generally from 4 to 6 feet high.

The graduated field fence is generally best used for livestock operations with young animals present, such as cow-calf or lambing operations. The graduated wire generally comes down to the ground, but can have a single barbed wire underneath to prevent bottom entry, and is closely spaced. These fences both keep the young animals from rolling or crawling out (while lying down), and keep predators such as coyotes and dogs out. They also generally have barbed wire strands on top to keep the adults from leaning over the fence to get the “greener grass” on the other side and breaking down the fence. The top wires of this fence type must follow the “10-inch” spacing rule and kept tight, since they have killed more deer by leg snare than any other type. These fences should also be used in interior areas where possible, and not as perimeter fences if there is wildlife habitat present where you should allow wild animal passage or to get off the road. They also keep dogs in, but the fence should be buried in the ground some 18” to keep them from digging out, or to keep predators from digging in.

3)   Non-Climbing wire (welded).

This fencing is generally used for horses, and uses solid frames and non-climbing wire (welded), and should be about 6 feet high, or higher for jumping horses. This height keeps most horses from jumping, or leaning on the top, which breaks down the fence. Most adult deer can jump 6 feet flat-footed on a vertical and flat fence and it takes a fence 8 feet or higher / or with a leaning top to keep them out. This type of fence should not be used for perimeter fencing of areas that contain wildlife habitat. Where adult horses are used, but not kept, the bottom of the fence can be lifted 12 to 18 inches to allow for wild animal passage when the area is not in use.

4)   Illusionary Fencing

Deer have visual limitations that allow variable fencing. Deer can detect movement quickly, but have poor depth perception and cannot determine what to do with fencing which is not vertical, flat, and regular. A staggered 5-foot picket fence (on average) has been effective at keeping deer out of roses and gardens. Outriggers and leaning fences add depth, and most 5 foot high fences are not entered when they are leaned out, or have an out leaning top. Some experimenting may solve your problem with less effort and materials. Raccoons and opossums also have difficulty walking on uneven surfaces, but little keeps them out if there is a way to climb in.

A single monofilament fishing line has been successfully used as a gate at 3-4 feet in height and put up at night across driveways and entryways. Flowerbeds have survived in the wild with a small fence built with monofilament line. Deer are startled when they touch something they cannot see, and will leave it alone. Single electric wires with an electrical “pop” will also be avoided.

Exclusion fencing

is designed to keep wildlife out. Each species may require different fencing designs and types, and many can be used for multiple species with similar habits and ability. The principle that should be followed for exclusion fencing on a property, is to allow wild animals to use as much of your property as possible, and restrict them only from your designated “living space” or “agricultural or garden space.” This includes vineyards and other agricultural operations, where the fencing should be close to the activity, and used just around such areas. You can fence off your lawn, garden & flowerbeds with your house and other close structures, and let wildlife have the run of the rest of the property. This then provides for broad wildlife corridors and large areas of connected habitat. For corridors, you want as large an area as you can supply, and many paths and smaller corridor units can add passage choice and reduce predation by clever species like the coyote, who learn quickly where game trails, fencing, and other features are that will aid their feeding strategy. Double cattle guards work well to keep deer out of such areas if you don’t want to use a gate, but use round bars and avoid flat topped ones that deer learn to walk on to cross.

Perimeter exclusion fencing should not include wildlife habitat, or, wildlife habitat should not be needlessly excluded from wildlife use as habitat can be fragmented and entire local ecosystems disrupted. This is now a serious problem in many areas for a wide range of animals, and many fences are unnecessary. You can partially correct this problem in existing fencing by making openings at strategic locations to allow animal passage (drainages, corners)v.

The standard vineyard and personnel fence is 8 feet high on T-posts at 8 feet intervals, set down to ground level. The standard exclusion fence for housing areas is a wooden fence 7 to 8 feet tall that animals can’t see through. This type of fence should be used only around the agricultural or living area, within the property boundaries if possible to allow for animal corridors. Corner gates are important in these fences for letting animals out. No matter what you do, someday you will find an animal in your yard and not know how it got in. if it’s a deer, they are almost impossible to drive through a side gate, but will easily walk out a corner gate. Make vineyard units small, exclusion fence just the vineyard block, and allow corridors.

Corridors

are critical for wildlife, and streams and other drainages are the most important areas for corridor planning. Fencing across creeks should be avoided, as well as allowing grazing animals to access perennial creek habitats. Create distinct grazing ranges or area separations with fencing that parallels the creek, and allow as much open space along the creek as you can. Grass filter strips along creeks and drainages, as well as secondary grassed drainages have proven to be critical for pollution filtering and can be more important for this function than flowing creeks. One hundred feet setback on each side is a good guide, but do what you can. A larger setback will allow for more tree, shrub, and grass habitat along upper banks and provide a higher quality corridor as well as reduce erosion losses. Where there are few corridors, the corridor should be much larger (300 feet +) to allow mixed habitat travel lanes and reduce predation. The guide here is “the bigger the better.”

5)   Fencing for Problem Wildlife

Wildlife such as raccoons an opossums can climb about anywhere, are generally after food, and can be huge pests. A dog used within such an enclosure will generally discourage wildlife entry, but night interactions can be a problem and a large raccoon could discourage wildlife entry, but night interactions can be a problem and a large raccoon could hurt your dog. Animal food should be brought in (feed in morning with just enough for them to eat), garbage cans should be put away with the lids secured, and no food should be left out. This also keeps mice and rats away, and their predators such as rattlesnakes.

Electric fencing

can be very effective in protecting your yard. They are very good at keeping most wildlife, including bears away. One electric power unit can drive some 2 miles of wire, which is of small diameter and very pliable. This means that you can easily fence most yards with one unit, and you can be very creative with where you run the wire and how you shape your fences. A single strand down the top of a fence, or across beams or other wildlife access points, can be a very effective deterrent. Try not to have tree limbs cross the fence and allow animal access from the top. Electric fences use an electric pulse, and do not “grab” you like an electric wire that can electrocute, but you will let go and probably remember not to touch it again intentionally. Wildlife won’t forget a shock.

Mt. Lions

are present in most wild areas and habitats, but they are rarely a problem. They are known to take cats and dogs, goats, sheep, calves, etc., and pets should be restricted to yards and/or brought in at night. If there is potential for attack in kennels, put on a wire top and use electric wires around the edges. To reduce predator access to livestock, bring them in at night, and use electric fencing. Avoid biking or running alone during the dusk, night, and dawn periods where and when lions hunt, since you could be mistaken for a deer. Multiple persons in a party will generally deter an attack. If you have an encounter, don’t run, face the animal and make yourself look bigger. These actions make it clear you are not a deer, which is the most frequent confusion for the lion that is looking for a deer or other wildlife for dinner.

Coyotes

have a wide food supply and will eat your cats and dogs if they have the opportunity, but they are helpful to have around to remove excess raccoons, skunks, opossums, and other pests which can cause you grief if you do not manage the food supply around your house such as pet food, garbage, etc. These items will bring in pest wildlife, as well as predators hunting them. Fence a yard area with graduated wire or solid fence, with a buried skirt to keep them out (5 feet in generally tall enough, 6 feet is better), and keep your pets at home, and never leave a child out on a lawn or yard unattended or without protective fencing when coyotes are present. Grazing a burro, donkey or llama with sheep or goats will generally prevent candid attacks since these animals will try to stomp the coyote or dog and kill it…so you need to be aware of your own dog when using them for protection.

Foxes

may go after poultry or birds in aviaries, and fencing should be used to fully protect the containment areas. They are also great climbers and can easily obtain access if there are limbs or trees close to or over a fence.

Trespass:

Over time, one learns that trespass notifications, boundaries, or other notices can be posted at legal intervals on simple posts rather than use a continuous fence, and that wildlife can be controlled by the way you manage your garbage, flowerbeds, pet food, and internal fences.

For trespass, you also have to be ready to call the Sheriff or local police authority to report problems, and prosecute those who ignore warnings. It doesn’t take long before people “know” that they need to ask your permission before entering your land, problems generally end, and you may not have to put in a security fence. Anti-personnel fences generally become anti-wildlife fences, and deer and other animals can be restricted from critical habitat such as food, shelter, or water, which can destroy local populations. Often, incomplete fencing designed to cut off specific access points to control a problem area can be effective, while leaving large areas open for wildlife access and can be a good compromise.

Relocation of problem fencing: In the short term, fencing relocation can be expensive, but it may be cheaper in the long run to avoid animal problems and constant aggravation from a poor set up.

Hopefully these ideas can help you deal in a positive manner with the wildlife around you, and protect the native habitat and the wildlife that use it. Private landowners control a significant portion of the wild landscape, and can greatly assist their survival by wisely managing food and fencing on their properties.



Allan Buckman
Associate Wildlife Biologist
Central Coast Region

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