Wild horses and burros are some of the most recognizable animals on America’s public lands. They are also at the center of one of the Bureau of Land Management’s most difficult management problems.

There is no question that these animals are part of the story of the American West. But there is another part of the story that is harder to see: what happens when their populations grow beyond what the landscapes they inhabit can sustain.

The numbers are becoming difficult to ignore.

As of March 1, 2026, the Bureau of Land Management (BLM) estimated that 85,466 wild horses and burros were living on the range. The agency’s nationwide Appropriate Management Level (AML) — the number of animals it has determined the available habitat can sustainably support — is just 25,592.1

That means the population on the range is more than three times the level the BLM considers appropriate.

And the animals removed from the range do not simply disappear from the equation.

As of May 2026, approximately 58,025 horses and burros were being held off-range in short-term corrals and long-term pastures.1

This is where the ecological and financial costs begin to overlap.

What Happens on the Ground

The ecological impacts are not simply a matter of horses eating too much grass.

Horses and burros interact with landscapes differently than native wildlife and differently than managed livestock. They can travel long distances, concentrate around water, and repeatedly use productive areas that are especially important during dry periods.

A 2021 study of ten spring-fed meadows in Nevada found that free-roaming horses selected meadows at an average rate 51 times greater than the surrounding rangeland. The horses also stayed longer and grazed more intensely than cattle and domestic sheep.2

That matters because these wet meadows and riparian areas are some of the most productive parts of otherwise dry landscapes.

The researchers found that longer and more intensive use was associated with increased soil alteration and bare ground. The study sites overlapped with BLM horse management areas and Forest Service territories, public land grazing allotments, and core greater sage-grouse habitat.2

In other words, the places horses are most likely to concentrate are often the same places that provide disproportionately important habitat for other species.

That creates a difficult management problem: protecting one valued component of the landscape can come at the expense of another.

Sage-Grouse and the Habitat Around Sagebrush

The greater sage-grouse is often described as a sagebrush-dependent species, and that is true. But its habitat needs extend beyond sagebrush itself.

Wet meadows and other productive seasonal habitats provide important forage and brood-rearing opportunities. Damage to these areas can therefore greatly affect sage-grouse. The direct effects of horses and burros on sagebrush can range from trampling to browsing on young seedlings. But their greater impact on sage-grouse may come through the degradation of wet meadows and other mesic brood-rearing habitat.

A 2021 study by Coates and colleagues found that for every 50% increase in horse abundance above the maximum AML, sage-grouse abundance was predicted to decline by approximately 2.6% annually.3

A separate 2024 study looked at 15 years of data from central Wyoming, including nearly 1,100 sage-grouse nests and hundreds of broods and juveniles. The researchers found that increasing horse abundance from 100% to 300% of the maximum AML was associated with predicted declines in survival of:

These studies do not suggest that horses are the only factor affecting sage-grouse. They show something more specific: when horse populations substantially exceed the levels established for their management areas, there can be measurable consequences for a species already facing significant habitat pressures.

Burros and Desert Tortoises

Similar questions are emerging in the desert Southwest.

A study of the western Sonoran Desert examined twelve potential influences on desert tortoise presence. Of those factors, feral burro presence and vegetation association were among the strongest predictors, with a negative association between burro presence and tortoise presence.5

That does not mean burros are the sole cause of declining tortoise populations. Desert tortoises face a long list of pressures, including habitat loss, disease, invasive species, development, and changes in vegetation.

But burros can add another pressure to an already stressed system.

A 2024 study of established burro herds in the Sonoran Desert found associations between feral equids and changes in plant communities. Several native plant species showed reductions in ground cover, plant density, foliage density, or plant size in areas associated with burro use.6

The effects were not uniform across all species or locations. That is important too.

Good ecological management rarely comes down to a simple statement that one animal is “good” or “bad.” The question is how many animals a particular landscape can support without causing unacceptable changes to the ecological systems that depend on it.

The Price of Holding Animals

The ecological costs are only part of the problem.

The federal government is also spending substantial amounts of money maintaining horses and burros after they are removed from the range.

In fiscal year 2024, the BLM’s Wild Horse and Burro Program spent approximately $153 million. About $101 million — roughly 66% of the program’s total budget — went toward off-range holding.1

By comparison:

The result is a difficult cycle.

When populations grow beyond AML, the BLM gathers animals from the range. Some are adopted or otherwise placed. Many are not. Those animals then enter long-term holding, where taxpayers continue paying for their care.

Meanwhile, animals remain on the range and populations continue to reproduce.

It is an expensive way to manage an expanding population.

What Else Could That Money Do?

This is where the conversation becomes less about horses and more about priorities.

Every dollar spent maintaining animals in long-term holding is a dollar that cannot be spent somewhere else.

That could mean:

None of these priorities is inherently more deserving than a humane approach to managing wild horses and burros.

But public land budgets are finite.

When two needs compete for the same limited funding, the opportunity cost matters.

This Isn’t About Choosing Horses or Ecosystems

It is tempting to turn the debate into a simple choice: protect wild horses or protect public lands.

That framing misses the real issue.

Wild horses and burros are living animals. They deserve humane treatment and responsible management.

At the same time, they are large, non-native herbivores living in ecosystems that evolved without them. Modern free-roaming populations descend from domesticated animals introduced to North America, which is why scientific literature sometimes uses terms such as “feral” and “non-native.” The terminology is contested, but the ecological question exists regardless of what we call them.

Both things can be true.

The goal should not be to fully eliminate these animals from public lands, nor should it be to allow populations to grow without regard for ecological limits.

The harder question is how to manage populations at levels that landscapes can actually sustain.

That means asking difficult questions about:

These are questions about whether public land management is actually working.

Landscapes Have Limits

The American West is a landscape defined by scarcity.

Water is scarce. Productive meadows are scarce. Riparian habitat is scarce. And the amount of money available to restore and manage these places is scarce.

Wild horses and burros are only one part of that equation.

But pretending that population numbers can continue increasing without consequences does not make those consequences disappear. They simply show up somewhere else — in degraded wetlands, altered plant communities, stressed wildlife populations, or larger federal budgets.

The challenge is finding a way to allow these iconic animals to remain part of the American West without asking the ecosystems around them to absorb an impossible cost.

Public lands belong to the American people.

They also belong to sage-grouse, desert tortoises, cottonwoods, grasses, springs, rivers, and producers.

Good management has to account for all of them. Are horses actually worth the consequences? If so, then we need to appropriately plan for and fund to remediate their degredation.

Sources

  1. U.S. Bureau of Land Management. Wild Horse and Burro Program Data.
    https://www.blm.gov/programs/wild-horse-and-burro/about-the-program/program-data

  1. Burdick, J., Swanson, S., Tsocanos, S., & McCue, S. (2021). “Lentic Meadows and Riparian Functions Impaired After Horse and Cattle Grazing.” The Journal of Wildlife Management, 85(6), 1121–1131.
    https://doi.org/10.1002/jwmg.22088

  1. Coates, P. S., O’Neil, S. T., Muñoz, D. A., Dwight, I. A., & Tull, J. C. (2021). “Sage-Grouse Population Dynamics are Adversely Affected by Overabundant Feral Horses.” The Journal of Wildlife Management, 85(6), 1132–1149.
    https://doi.org/10.1002/jwmg.22089

  1. Beck, J. L., Milligan, M. C., Smith, K. T., Street, P. A., Pratt, A. C., Kirol, C. P., Wanner, C. P., Hennig, J. D., Dinkins, J. B., Scasta, J. D., & Coates, P. S. (2024). “Free-roaming horses exceeding appropriate management levels affect multiple vital rates in greater sage-grouse.” The Journal of Wildlife Management, 88(8), e22669.
    https://doi.org/10.1002/jwmg.22669

  1. Berry, K. H., Yee, J. L., & Lyren, L. L. (2020). “Feral burros and other influences on desert tortoise presence in the western Sonoran Desert.” Herpetologica, 76(4), 403–413.
    https://doi.org/10.1655/Herpetologica-D-20-00023.1

  1. Rubin, E. S., et al. (2024). “Associations between a feral equid and the Sonoran Desert ecosystem.” Wildlife Monographs, 215(1).
    https://doi.org/10.1002/wmon.1083

  1. Wild Free-Roaming Horses and Burros Act of 1971, Public Law 92-195, as amended.
    https://www.congress.gov/bill/92nd-congress/house-bill/989

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