Virtual Fencing

Restoration projects and endangered species often need protection from grazing livestock and virtual fencing will often prove useful. Virtual fencing offers several advantages over conventional fencing (Blevins 2022, Bohnert 2023). Wire and wood fences are costly and vulnerable to damage from fires, floods, and errant autos, and pose a risk to wildlife (Jakes et al. 2018, McInturff et al. 2020, Xu et al. 2023). Wire fences can also be costly to install and maintain on boggy, rocky or steep ground and areas that flood. Virtual fencing uses electronic technology to create invisible fences that can control livestock movement over a large area. These can be easily adjusted and moved. The concept was first used in making invisible fences for pets in home yards. Recent advances have brought the cost down low enough to enable first adopters to try virtual fences.

Livestock are fitted with a smart collar. The boundary is set with software that links the collar to the virtual fence. This provides a warning and then a mild shock if the animal approaches the electronic boundary. The communication between collar and land manager varies with manufacturers. It may be done with a global positioning satellites (GPS), or GPS with existing cell towers or base stations installed for the fence at a cost up to $12,500 each (Blevins 2022; Bohnert 2023). Cow collars rent for about $50 a year or can be purchased for about $300 for cattle and $200 each for sheep and goats. They are expected to last five to 10 years. That may sound like a lot, but Washington rancher Mike Wilson estimates fencing just one of their 2,800-acre pastures using a physical fence would cost as much as $140,000 (Golden 2022). Neighboring ranches can reduce the cost by sharing base stations. A cooperative program with the Bureau of Land Management and Colorado Parks and Wildlife helped install 10 towers covering 500,000 acres.

Because some virtual fences can be readjusted on the fly from a cell phone or home computer, cows may one day be herded by satellite (Golden 2022). With more sophisticated systems ranchers can locate individual cows without leaving home. Mike and Joy Wilson's system provides them with nearly real-time accounts of the location of their 135 cows across thousands of acres about 40 miles from their home in Washington (Kamnitzer 2023). From their home in southern Okanogan County, they can watch the dozens of black cow icons on their computer screen. The Wilson’s cows wear collars made by Vence (Merck Animal Health, Rahway, NJ) and use the software to draw virtual fences on a map of the ranch. The fence coordinates are transmitted to the collars via two radio towers. Eliminating wire fences in this area is important because lynx, wolverine, wolves and grizzly bears use this area as a passageway between the Cascade Mountain range and the Rocky Mountains.

These electronic networks can create virtual fences that can be repositioned easily to facilitate range health (Shadbolt and Mesa 2024), protect riparian areas (Bohnert 2023) and endangered species. For example, virtual fences can be adjusted over the seasons to protect flowering and seeding of endangered species. Virtual fences could also manage invasive species by intensive grazing before seed set. Grazing using virtual fences has also been concentrated to create firebreaks (Boyd et al. 2023). Virtual fencing can be very responsive and flexible. It can be used in areas that are difficult to fence and will minimize or eliminate wildlife injuries common with traditional wire fencing.

Nevertheless, challenges remain. Virtual fencing is not cheap, but neither is building or rebuilding miles of fences after a wildfire. Batteries must be changed or charged, perhaps every six months but up to two years. Battery life will be shorter in applications like grazing fire breaks because animals in a corridor test the system as they see more food just a few feet away; this uses more energy. Animals may learn to accept the shock and cross fence boundaries to get better grazing. Collars can snag on objects or break, leaving an animal free to roam and more difficult to locate. The failure of a base station can also allow animals to roam freely. If a conventional fence fails it is usually a single breach, but if a virtual fence fails, it fails extensively, causing ecological as well as economic damage (we all remember what happened in the film Jurassic Park). Cell, tower, and GPS performance may vary depending on topography and weather. Severe winter weather or summer heat events have the potential to reduce battery power.

Virtual fencing can be a useful tool for the restoration ecologist, rancher, nature reserve and wildlife manager, and the planet. Cost sharing can reduce costs as agencies, non-profits, and businesses realize the collective benefits of virtual fences. Researchers and ranchers in the Northwest, Alaska, Colorado, Europe, and Australia are helping pioneer the development and use of these systems. The greatest value in the near term is likely to be for large land holdings, in the hundreds of acres. Vence, NoFence (Madison, WI), Corral Technologies (Lincoln, Nebraska) and eSheperd (Gallagher Animal Management Hamilton, Melville, New Zealand) currently offer virtual fencing systems. As more companies join the market, costs will decrease and virtual fencing applications will expand. Increasing availability will make it much easier for restorationists to include virtual fencing in specific projects and for long term management of nature reserves and cooperative projects with ranchers and farmers. Perimeter barbed-wire fences might still be maintained, but cross-fencing and interior fences of all kinds can be removed and replaced with virtual fences, adjusted as needed based on site conditions.

Milkweed (Asclepias spp.) seed with tufted coma. Asa Gray. 1887. The Elements of Botany for Beginners and for Schools. New York, Cincinnati, Chicago: American Book Company, fcit.usf.edu.