From a distance, the cattle grazing at the Land of the Swamp White Oak Preserve in southeastern Iowa look like they’re wearing cowbells. But instead of metal domes and clappers, these accessories are outfitted with global positioning system (GPS) chips.
Staff with The Nature Conservancy, the organization that owns and manages the 4,000-acre preserve, can track the locations of the collared cattle from a smartphone app. They can also draw and adjust virtual fences to graze cattle in certain areas with invasive weeds – and keep them out of ecologically-sensitive wetlands and floodplains.
When a collared cow moves toward a virtual fence, it hears a tone, which gets louder and eventually releases an electrical stimulus on the back of its neck.
“For the majority of these cattle, that's enough to turn them around. They don't stop grazing. They just keep going but change direction,” said Amy Crouch, who oversees sustainable grazing projects in Iowa through The Nature Conservancy.
Since 2023, she said staff have tested virtual fencing systems from two companies as part of a pilot project at the preserve. Calves and bulls don’t need collars since they follow the cows, Crouch added.
The virtual fencing reduces the need for physical posts and barbed wire – which can be difficult to maintain in areas with frequent flooding, like the preserve’s oak savanna floodplain.
“A big benefit [of virtual fencing] is not having to consistently rebuild fence,” Crouch said. “And that's not just a benefit for us. That's a benefit for private producers, too.”
Virtual fencing has evolved significantly since the 1980s when researchers tested shock collars on goats. But the technology is still relatively new and only recently became commercially available.
“One reason we wanted to do a pilot is so we could take that risk off of farmer’s shoulders,” Crouch said. “They'd be able to come to field days and see how it worked and ask questions before they decided to invest [in something new].”
The pilot project recently concluded at the preserve. But staff are continuing to experiment with virtual fencing and track its impacts on native plant diversity, invasive species and forage for cattle.
Beyond Iowa, The Nature Conservancy and partners are nearing the end of five-year virtual fence projects in Kansas, New Mexico and Colorado. William Burnidge, special projects director for The Nature Conservancy's North America Regenerative Grazing Lands Program, said more are taking place in California, Montana and Wyoming.
Virtual fencing can improve the management of grasslands and grazing with “unprecedented flexibility and precision,” Burnidge said. This includes concentrating cattle in a small area to graze before moving them to a new section.
“They're actually eating the same amount of grass, just in a shorter amount of time, and that provides for a longer recovery period [for the grass],” Burnidge said.
Ranchers often use paddocks or electrical fencing for rotational grazing, but it requires more time and labor than virtual fencing.
Virtual fencing also allows ranchers to concentrate grazing in areas with highly flammable vegetation that poses a wildfire risk, said Burnidge. And it can help producers adapt quickly to wildfires and floods by moving cattle out of harm’s way.
He emphasized there are still good reasons for physical fences along roads, railroads and neighborhoods. But virtual fencing reduces the need for interior fences, which can block the migration of wildlife, like pronghorn and elk.
Ranching and prairie conservation in the Flint Hills
Daniel Mushrush and his family ranch in eastern Kansas in the Flint Hills, the largest remaining stretch of tallgrass prairie in North America. He’s been using virtual fencing as part of The Nature Conservancy’s project since 2022.
Mushrush said he was eager to try something that could make ranching more precise. He attended Kansas State University in the early 2000s, right as precision agriculture for row crops was taking off.
“A lot of my college friends were doing things with ag technology on corn and soybeans. It just, quite frankly, made me jealous,” Mushrush said.
The biggest benefit of virtual fencing is more time and flexibility, especially during the calving season, he explained.
“I used to calve in about 1,000 acres of grass in the fall herd, and it would take me about 20 to 25 miles on a four-wheeler a day,” Mushrush said.
With virtual fencing, Mushrush said he can tighten the boundaries for the herd and expand it out for individual cows after they’ve calved. Now, he spends half an hour checking them instead of three-to-four hours.
That opens up more time to focus on other aspects of ranching and his family. Mushrush said he used to miss his kids’ softball games and music concerts because he needed to check on cattle or move them to new grazing ground. Now he can track them from his phone and schedule changes to fence boundaries.
Mushrush added that traditional fencing material is expensive and difficult to construct in places like the Flint Hills. Inserting t-posts often requires boring holes first.
He emphasized virtual fencing also creates a win-win situation for the ranch and conservation efforts.
That’s important because almost all of the land in the Flint Hills, which span from eastern Kansas to northeastern Oklahoma, is privately-owned, said Tony Capizzo, Flint Hills Initiative Director at The Nature Conservancy.
"It's critical habitat, both for resident prairie species, things like greater prairie chicken, ornate box turtle, but also migrators,” Capizzo said.
Better nesting habitat for grassland birds
Through the five-year Flint Hills project, several researchers have explored how virtual fencing can help protect and improve nesting habitat for grassland birds.
Some species have declined more than 67% in the past 50 years, according to the latest State of the Birds report, an annual status assessment of the health of U.S. bird populations. Habitat loss is one of the biggest factors.
“Each species needs something a little different, and sometimes they need different things at different stages of their life,” said Alice Boyle, a biology professor at University of Western Ontario in Canada who was a lead researcher on the project for several years when she was with Kansas State University.
For example, common nighthawks depend on bare, gravel patches to lay their eggs while other species need dense, tall vegetation, she explained. With prairie chickens, males prefer hilltops with low vegetation to draw in females, but females require tall, dense vegetation nearby to nest.
“Being able to create that patchiness is key for these grassland birds,” said Theo Michaels, a postdoctoral researcher in the biology department at Kansas State.
Virtual fences and grazing cattle can help create those conditions, Michaels and Boyle said.
Other Kansas State researchers are studying how virtual fencing can help protect and restore prairie headwater streams, which Michaels said are important for biodiversity and water quality.
They found that virtual fencing around streambanks increased vegetation and boosted invertebrate diversity. Data collected to measure nutrients in the streams is still being processed, Michaels added.
For virtual fencing to become more widespread in a way that braids together ranching and conservation goals, Michaels and Capizzo see an important role for partnerships.
This could include technical assistance to design grazing plans and programs to reduce risks for ranchers interested in trying virtual fencing.
Will the technology catch on?
The cost to implement virtual fencing, especially at the scale of a ranch, can be a barrier, Burnidge said.
Researchers from Oklahoma State University and Colorado State University found the collars are often the most expensive part of the virtual fence system. Leasing a collar typically costs around $55 per year while purchasing it outright lands around $300 with an expected five-year life.
The costs for software and equipment vary significantly by company and the packages they offer, the researchers said.
At the Land of the Swamp White Oak Preserve, Crouch said the costs of virtual fencing are on par with physical fencing over time. But from Burnidge’s perspective, trying to draw direct price comparisons is similar to comparing “apples and fried fish.”
“You can't do with barbed wire or electric fence what you can do with virtual [fence],” Burnidge said.
Mushrush recommends ranchers and livestock producers interested in virtual fencing should take time upfront to find out what products will work best for their operations.
For instance, at the beginning of the Flint Hills project, Mushrush said water easily seeped into the cattle collars, creating technical issues. They switched to a different company based in a part of New Zealand with high precipitation.
Both Musrush and Crouch said cattle learn how to respond to virtual fencing quickly, often within a week of training. Sometimes the biggest barrier is cultural.
“Ultimately, I think you have to have a really hard conversation with yourself,” Mushrush said. “Are you willing to truly change the way you manage your ranch at the fundamental level?”
Mushrush said the ranch has expanded its use of virtual fencing beyond the project with The Nature Conservancy. And other ranchers in the Flint Hills have either begun experimenting on their own or expressed interest, said Capizzo.
“We don't necessarily know all the ways we might be able to use this technology to manage differently, and so, as more people get involved … it'll be really interesting to see just more of those ideas being tested,” Capizzo said.
This story was produced in partnership with Harvest Public Media, a collaboration of public media newsrooms in the Midwest and Great Plains. It reports on food systems, agriculture and rural issues.
