University of Wyoming scientists are embarking on a new study to track the movements of wild horses in the Red Desert.
The study involves the use of radio collars — a first for wild horses in Wyoming. The first horses were collared last week, and up to 30 mares are expected to be part of the two-year project.
Derek Scasta and Jeff Beck from the UW Department of Ecosystem Science and Management, along with Ph.D. student Jake Hennig, are leading the research.
The aim of the study, which has funding from the Wyoming Department of Agriculture and the Bureau of Land Management, is to gather vital information for wild horse management in particular and rangeland management in general, Scasta said.
“There’s a lot of unanswered questions about where they come from and where they go,” he said. “And really the only way to answer those questions is to track them.”
Scientists estimate about 67,000 wild horses and burros live on rangeland in 10 Western states — including 6,500 in Wyoming — plus tens of thousands more living in sanctuaries.
The BLM has federal authority to manage and protect the horses as part of its multiple-use mandate. According to its own estimates, a population of no more 26,000 horses is appropriate for the habitat they occupy.
“It’s a big, big challenge, and the issue is the potential degrading of the rangeland resource these horses have to have,” Scasta said.
Horses share that habitat with a number of other animals, which affects management of those species. For example, scientists know there’s a substantial overlap between sage grouse core areas and wild horse areas, but no research has been done to learn more about what that means for either species.
“We want to try to pull some of that apart some more,” Scasta said. “If we try to manage all these other species, but we’re unable to manage horses, that’s a potential problem.”
Radio collars haven’t been used on wild horses very often because of problems with projects several decades ago that resulted in injuries and mortality among some horses. Scasta and Beck said researchers have learned from previous mistakes and the technology has improved.
Using a bait-trap method, horses from the Adobe Town herd management area are being gathered into temporary corrals. The 500,000-acre study area sits between Interstate 80 and the Colorado border, with Wyoming Highway 789 on the east and Wyoming Highway 430 on the west.
From there, personnel transport healthy older mares to a holding facility where they are fitted with collars with GPS tracking devices. They’re observed for 48 hours before being returned to the wild from at same location.
The collared mares are all at least 5 years old, so they’re done growing. Stallions aren’t used because their behavior is more aggressive and could cause problems with the collars. A third-party veterinarian on site ensures that elected mares are healthy and mobile.
The collars will record the horses’ locations every two hours for the next two years, and scientists have real-time access to the data via satellite.
Hennig said he plans to check on the horses once a month to assess how the collars are fitting. In the meantime, he’ll receive a daily update about each horse, and he’ll be notified if a horse hasn’t moved for six hours.
“I’ll get a text and an email to let me know, and I can go check on them,” Hennig said.
If he needs to, he can even remove the collar remotely by entering a code.
“It will fall off immediately,” he said.
The scientists are hoping to learn where the herd spends its time as it roams the checkerboard Red Desert, a mixture of public and private land used by ranchers and wildlife alike and fraught with potential conflicts. They also want to know if the herd migrates or spends any time in Colorado.
Beck said the amount of data will be remarkable, and far beyond anything researchers could gather by other methods. Plus, it will reveal horse behavior while free from a human presence.
In the rangeland habitat, riparian areas are highly prized by ranchers and wildlife alike, and Beck is looking forward to learning more about how horses use those areas.
“We can learn the time of day they use them, how long they’re there, and relative amount of time they spend there,” he said.
A similar GPS-tracking project conducted several years ago, also in the Red Desert, revealed a previously unknown mule deer migration. That discovery sparked the development of the Wyoming Migration Initiative and efforts to protect the 150-mile migration corridor from further development.
Scasta said he’s hoping this study advances the field of horse ecology and leads to better management.
“This is a frontier of large, free-roaming animal research,” he said.