Wild horse management is a divisive issue in the West. Management costs millions of dollars, yet little is known about how the animals use the range. A new study by the University of Wyoming and the Bureau of Land Management will use satellite collars to track horse movement for two years in the Adobe Town Herd Management Area near Rawlins. (Bureau of Land Management)

About 6,500 wild horses roam the rangelands of Wyoming. The horses are beloved by some as a symbol of the West and despised by others as feral animals competing with livestock for rangeland resources. They cost the Bureau of Land Management millions of dollars to manage. Yet little is known about how wild horses use the landscape.

A new study from the University of Wyoming and the BLM is hoping to change that.

In mid-December researchers will collar 20 mares in the 400,000-acre Adobe Town Herd Management Area. The collars will collect data on the animals’ movements across the checkerboard of public and private land for the next two years.

The study is one of the first to track wild horse movements in the United States, said Derek Scasta, assistant professor and extension rangeland specialist at the University of Wyoming.

“No matter your position on wild horses, we don’t know enough about their ecology — as we should,” he said.

Satellite-tracked collars will show how the horses move and give insight into how they select resources and what vegetation they prefer.

Scasta will use the data from the collars and information on vegetation in the areas the animals use, to determine not just where the horses go, but when and why.

“It’s amazing these horses survive Wyoming winters,” Scasta said. “So what site selection do they have to go through to do that?”

Wild horses also move between public and private land, and between different management areas.

Wild horse specialists work to keep herd numbers at specific levels for each management area, but the animals don’t recognize the invisible boundaries. Managers could work diligently to keep the wild horse population at a desirable level, only to find horses from other management areas move in, said Tim Novotny, assistant field manager for resources in the Rawlins BLM office.

Wild horses run on BLM land in the Adobe Town Herd Management Area. Researchers are planning to collar 20 mares in mid-December to track the animals' movements for two years. (Bureau of Land Management.)
Wild horses run on BLM land in the Adobe Town Herd Management Area. Researchers are planning to collar 20 mares in mid-December to track the animals’ movements for two years. (Bureau of Land Management.)

Data gathered in the study can help the agency make decisions on management issues, such as how a proposed water development for livestock or other wildlife might impact the horses, Novotny said. The area also has oil and gas development, and how the horses react to drilling areas could help guide future development. Novotny said they want to see if the horses avoid developed areas, and if they return to those places once drilling is done.

The BLM will use bait trapping to collar the horses. Novotny said the goal is to capture about 150 mares in order to collar 20. That should ensure the tracked animals come from different herds using different parts of the landscape within the Adobe Town management area.

Other countries have conducted similar research, but after horses died in studies in 1986 and 1991 in the United States, scientists stopped using collars on the animals. Technology has improved since then, Scasta said. Collars are better designed now and when properly used are safe for the animals, he said.

Scientists can push a button and the collars will drop off. They don’t have to capture and handle the animals a second time to gather the data, Scasta said. These types of satellite collars have successfully been used on other animals and birds, such as bears, wolves and sage grouse.

The BLM is charged with managing wild horses to preserve the health of both the animals and rangeland. Strategies include gathering animals when populations are high and putting them in holding facilities in hopes they’ll be adopted, or administering birth control to slow reproduction in herds.

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There are more than 67,000 horses and burros roaming free in the United States, Scasta said. That is far more than the 26,000 the agency believes is the appropriate number for herd and rangeland health. Meanwhile, another 45,000 wild horses and burros are already off range in holding facilities.

“That’s why this is a difficult issue,” Scasta said. “That costs a lot of money.”

Animal rights groups have focused efforts on ensuring killing the animals is not part of the government’s strategy. Scasta emphasized the study isn’t about finding ways to eliminate the animals, but to learn how to better manage them.

“We have to co-exist,” he said. Humans and horses share the landscape, but they have to learn to do it well, he said. The study is the first step.

Kelsey Dayton is a freelancer and the editor of Outdoors Unlimited, the magazine of the Outdoor Writers Association of America. She has worked as a reporter for the Gillette News-Record, Jackson Hole News&Guide...

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  1. I suspect this is more to see if the horses step over the imaginary property lines that are the checkerboard. If they do, RSGA will cry like babies and all the horses will be removed. Connect the range for them and leave them alone.
    I would be more worried about the 8,950 gas wells coming in, than a few horses.

    1. Here! Here! to Mr. Miller.
      It would be good if the larger public that sees the beautiful pictures of wild horses running free in a field could see what happens when drought conditions destroy the habitat where these animals live–the water sources and the feed is gone.–It’s not a matter of whether there is any other domesticated animals living there–the consequences are hideous to see. I grew up loving horses–watching them, riding them. But I have seen what the overpopulation of horses does to the terrain. These lovely creatures have 4 hammers for feet and nippers for teeth. Different from cattle or other wildlife, these animals can tear grass along with the roots out of the ground or bite below the growth plate of a plant. They can (and do) destroy their own forage areas. In Wyoming range land, it takes anywhere from 20-50 acres per animal unit to sustain quality life. What wild horse advocates complain about are the ranchers who hog public lands–but they don’t seem to consider that there are other animals trying to survive on the same lands where the horses are. With the numbers of wild horses that exist today, there simply isn’t enough forage for them or other wild creatures–let alone the range cattle or sheep that ranchers run. And it is far more likely that ranchers are managing for grass and habitat than those who have no financial investment at stake.

      Take a look at photos of animals found in desert areas (largely where they roam) during droughty seasons. It is brutality caused by kind-hearted people.

  2. As a long time horse owner I can attest that leaving anything around a pastured horse’s head or neck is very dangerous. The animal can easily get hung up on any number of things….,branches in particular. This is a very poor choice to track free roaming animals. Secondly, before any such ‘study’ is done, I would like to know the actual numbers of cattle that roam over these same areas.

  3. There are livestock handlers, range managers and other outdoors enthusiasts who could supply the information that will be gathered and I hope will be considered. It also needs to be a long-term study. Just one or two years will not provide valid or useful data. What the horses eat and where they go on the range is decided the weather and its timing. Late winter or spring, a dry year, abundant feed and water some years and the opposite other years, horses will follow the food and water which varies from year to year, especially in the marginal range land where most of them are. Some of the good stockmen and others have been watching the range for generations and already have much of the knowledge, but we do need the peer reviewed studies to back up what they already know and they will learn from the studies as well. These studies will not help with the problem of growing horse populations. Every good stockman, range manager and others already know what needs done. In these marginal range lands livestock needs managed. And yes, horses are livestock, not a native species. The wild horse advocates need to suck it up, face reality and accept the removal and disposal of excess horses, including unrestricted sales and euthanasia. Stockman, range managers, big game managers and others understand this well. They know congressional action, emotions and magical thinking do not change nature or reality.

  4. I think it is great the WyoFile makes solid information about wild horses available. Keep it up! On the other hand, the comments from Marybeth Devlin are very misleading. The independent study showing normal population growth of 5% does not stand up under any sort of scrutiny. They cherry pick information to find numbers that will show what they want. Their study would not be accepted by any reputable journal that supports peer reviewed studies that are held to a scientific standard. The information from the study is wrong. The rest of numbers addressing growth are reached using the study, and because of that have no meaning. Those numbers have nothing to do with reality. If you would like information that has been reviewed using scientific standards check out the following web pages – The Wildlife Society – Feral Horses & Burros in North America Final Position Statement – National Academies of Science, Using Science to Improve the BLM Wild Horse and Burro Program: A Way Forward – Preface – Summary.
    Horses are not a native species of the desert of the Great Basin or of Southwestern Wyoming. Their Natural habitats are grasslands like those in Texas, Oklahoma and Kansas. We could solve many of the wild horse problems by moving the Wild Horse and Burro Program to those states. For a different point of view; In the Great Basin Mustang Free by 2023 and go to 45 Years of the WH & B Program.

  5. Per a request from the University of Wyoming, BLM will help fund the subject research project, which is an add-on to a different multi-year study, already in progress, that is receiving funding from the Wyoming Department of Agriculture. The original proposal was to investigate movement and habitat-selection patterns of wild horses of the Stewart Creek, Green Mountain, and Crooks Mountain herd management areas (HMAs). However, it was amended per discussions with BLM staff to focus, instead, on the WY-CO border-HMAs. Among the study-objectives are to understand how the wild mares move across that border. There are 3 HMAs on the WY side — Adobe Town, Divide Basin, and Salt Wells Creek — and 1 HMA on the CO side — Sand Wash Basin. There is ample opportunity for the wild horses to move back and forth across the HMAs and across the border, which appears to be the case. As free-roaming wild horses, they do not domicile in a specific HMA.

    The research-results will surely be confounded, however, because the Colorado herd is also being rounded up, with 50 of its youngsters removed. Most of the mares will be injected with an endocrine-disruptor pesticide-sterilant known to cause, among other adverse effects, loss of band-fidelity, with mares changing allegiance aberrantly. Capture and captivity also disturb subsequent behavior. It is likely that many of the horses will be rounded up twice — once in WY, again in CO, or vice versa. The tracking-collars remain of concern due to injuries and deaths they caused in previous studies. One positive is the use of bait-trapping in place of helicopter-stampedes.

    BLM-Wyoming’s wild-horse population-estimates defy credulity. Per an independent study, normal population-growth is 5%, consisting of a 20% birth-rate reduced by 50% foal-mortality and 5% adult-mortality. However, for just one year, BLM posted the following herd-growth figures:

    71% — 14 times the norm — for Adobe Town,
    237% — 47 times the norm — for Divide Basin, and
    522% — 104 times the norm — for Salt Wells Creek.

    To achieve that much net growth in spite of mortality rates, the respective birth rates would have to have been:

    152% for Adobe Town,
    483% for Great Divide Basin, and
    1,054% for Salt Wells Creek.