Bison and Tetons, Grand Teton NP, Wyoming. Photo George Wuerthner 

In a recent New York Times commentary, author Dayton Duncan celebrated what he termed as the ongoing restoration of bison across the West. Hundreds of thousands of bison reside in the US on ranches, Indian reservations, and state and federal lands.

That may sound like a wildlife success story. However, what is not commonly admitted is that nearly all bison herds are domesticated to one degree or another. Many are to some degree compromised with cattle genes. Most bison are culled, inoculated against disease, fed supplemental hay, protected from predators, and selectively bred. Most herds are too small to avoid genetic inbreeding.

Yet many conservation groups assert that the mere transfer of bison to tribal reservations is equivalent to preserving wild bison. For example, Earth Justice suggests that the bison confined to a 15,000-acre “bison ranch” preserves “wild” bison.

Bison among Yellowstone’s thermal features. Photo George Wuerthner 

The most ecologically and evolutionarily intact bison are found in Yellowstone National Park. The Yellowstone bison have been shaped by disease, harsh winters, predators, and migration to a greater degree than any other bison in the West. This makes the Yellowstone herd of international significance. It is a global treasure.

Yet the state of Montana treats these bison like vermin. Except for a small region just immediately north of Gardiner, Montana, bison migration from Yellowstone is prohibited due to concerns about the potential transmission of brucellosis from bison to cattle,

It’s important to note there has never been a documented case of brucellosis transmission from wild bison to cattle, though elk have infected numerous cattle herds.

Yellowstone National Park is home to least domesticated herd in the West and of international significance. Photo George Wuerthner 

Killing or removing the globally significant Yellowstone bison from the Greater Yellowstone Ecosystem is a crime against nature. Whether removal is done to preclude the presumed disease transmission, to provide food for tribes, to transfer bison to reservations (privatization of public bison), or other reasons, it is analogous to blowing up giant sequoia and turning the wood into fence posts.

Claiming that bison restoration is a success is analogous to arguing that salmon restoration is a success when rivers are flooded with hatchery fish.

Numerous studies have demonstrated that hatchery fish are inferior to wild fish. They spread diseases, compete with wild fish for food and habitat, and gradually lose their ability to avoid predators.

In essence, claiming that hundreds of thousands of bison that are scattered over the West represents a “success” is like claiming hatchery runs of salmon is saving the species.

Tribal hunters killed more than 25% of Yellowstone’s northern herd this past winter. This slaughter represents a “domestication” of Yellowstone’s bison. Photo George Wuerthner 

The removal of bison and transfer of bison to Indian reservations, tribal hunting at the park border, and testing and slaughter of bison is eroding the wildness of Park bison.

When bison attempting to leave Yellowstone National Park are killed or removed it inhibits the expression of migration and mobility, which is the bison’s major evolutionary adaptation to shifting ecological conditions. The killing of entire family groups is entirely different from native predators, which tend to kill the old and young.

Removing bison from the park ecosystem reduces their influence on park vegetation and takes food out of the mouths of wolves, grizzly bears, and scavengers.

Population reduction also reduces intra-bison competition, which is the essential element of wildness.

Bison carcasses killed by tribal members north of the Park border near Gardiner, Montana. This represents a vandalism of globally significant wild bison. Photo  YellowstoneVoices.

So, how do we preserve bison wildness? First, to the greatest degree possible, we must permit natural evolutionary processes like predation, starvation, functional breeding populations, and migration to dominate Yellowstone bison.

This means we must halt the artificial selection process created by tribal hunting, test and slaughter, and even bison transfers, all of which are turning Yellowstone’s bison into “hatchery animals.”

We can encourage the migration of Yellowstone bison out of the park onto other public lands by halting the annual slaughter of animals at the park borders.

The Charles M. Russell NWR is an ideal place to expand wild bison in Montana. Photo George Wuerthner 

We should stop privatizing public bison by the transfer of Yellowstone animals to Indian reservations. If there are any “surplus” bison, the federal government should transfer this public wildlife to other federal lands like the Charles M. Russell NWR. This can be done over the wishes of the state of Montana or other groups since the Constitution’s Supremacy Clause gives the federal government ultimate power to manage lands under its jurisdiction.

Bison calf and cow. Yellowstone National Park. Photo George Wuerthner 

Yellowstone’s wild bison are too valuable to kill. We must stop the vandalism of our national mammal and begin to treat Yellowstone’s animals as the extraordinary public treasure they represent.  To learn more, go to Montana Wild Bison Restoration. Other groups to support includes the Gallatin Wildlife Association, Yellowstone Voices  Alliance for Wild Rockies and Roam Free Nation.


About The Author

George Wuerthner

George Wuerthner is an ecologist and former hunting guide with a degree in wildlife biology

13 Responses to Save Wild Bison

  1. Ida Lupine says:

    Correct me if I am wrong, but something is very wrong when it is proven that elk transmit brucellosis, but not one bison has spread it, they just are not wanted by ranchers on ranchland, and elk are wanted by hunters? It’s another case where demand for beef is the cause of harm to our lands and wildlife. The Native hunters may or may not have claim to the lands where they now are permitted to hunt bison, which is my understanding from previous articles posted of George’s?

    I don’t know why this myth is allowed to continue, when bison are our country’s own unique native wildlife which we should be proud to have and preserve:,many%20occasions%20where%20elk%20transmitted%20brucellosis%20to%20cattle.

    • Jerry Thiessen says:

      It’s BS. Let’s never forget that brucellosis was first brought to elk and bison by domestic cattle and not the other way around.

    • Jeff Hoffman says:

      The cattle industry pushes all this BS. As long as people continue to be obsessed with eating beef, they’ll never question it.

  2. Ida Lupine says:

    From Newsweek:

    “Humans have increased the rate of species extinction by approximately three orders of magnitude over the background rate (Pimm et al. 2014). Consequently, of roughly 40,000 known species of vertebrates, 20% are believed to be at elevated risk of extinction (Hoffmann et al. 2010). Those statistics are important and grim, but they also represent an inadequate understanding of the biodiversity crisis. Biodiversity loss is driven not only by worldwide extinction but also by the contraction of species’ geographic ranges. Therefore, an adequate account of the biodiversity crisis requires due concern for the majority of studied terrestrial vertebrates having been extirpated from 60% or more of their geographic ranges (Ceballos and Ehrlich 2002, Ceballos et al. 2017). The cumulative effect of these contractions means that disturbingly large swaths of the Earth’s land have lost substantial portions of their native biodiversity. For example, one study (Ceballos and Ehrlich 2002) showed that most native mammalian fauna, including common “species of low [conservation] concern,” have been extirpated from more than 50% of the coterminous United States. Similar patterns are found across the planet.”

    The wolverine has finally been added to the list of threatened species, but because of climate change, not trapping. One article I read didn’t even say ‘trapping’ by name, but called it ‘additional stressors’. Trapping is the major threat to the wolverine, IMO.

    • Jeff Hoffman says:

      I don’t know how to calculate an order of magnitude, but my understanding is species are becoming extinct at 1,000 times their natural rate because of humans.

  3. Ida Lupine says:

    I was happy to see that the study was co-authored by Dr. Bruskotter who has contributed many articles here at TWN, and Dr. Vucetich, who we know from the wolf and moose studies at Isle Royale, among others. It gives it plenty of credence IMO!

    The fact that our wildlife is disappearing at 3 times the background rate of expected loss is startling and needs to be addressed.

    I should have included the Newsweek article that discusses it, how the promotion of hunting over protection of species is not helping to curb biodiversity loss and protect species, which is what the government agencies are also tasked to do. The wolverine is a prime example, trapping is the more immediate danger to them than climate change:

    • Jeff Hoffman says:

      Again, it’s 1,000 TIMES the normal rate, not three times, which would be bad enough.

      • Jerry Thiessen says:

        There is no “normal” extinction rate.

        • Jeff Hoffman says:

          Yes, there is. The average life of a species is 1-2 million years, then they go extinct. SCIENTISTS have said that humans are causing extinctions at 1,000 times the normal rate.

      • Ida Lupine says:

        I guess math was never my strong suit. 🙂

  4. Ida Lupine says:

    No human-caused extinction should be acceptable, I agree, whether due to carelessness, neglect, human superiority or human-caused climate change.

    But the reality is that there is, it can be measured, and to have it measured to be worse than anyone thought is very disturbing.

    For animals whose populations are dangerously low, I don’t know how trapping can be controlled, except to ban it from the snowy habitats of the wolverine and lynx.

  5. Joanne Favazza says:

    Great piece, George. Agree 💯 percent.

  6. Ida Lupine says:

    Sorry, that article may not have gone through in its entirety. I’m not particularly fond of the tone of it either. Barred owls are no worse than humans when it comes to being predators and surviving. But we give ourselves a free pass.

    Here’s another from Newsweek. I just find this killing of them to be as unethical as can be. 🙁

    I’m not trying to change the topic from bison either, because it is all part of the same problem with the way we deal with our wildlife:


December 2023


‎"At some point we must draw a line across the ground of our home and our being, drive a spear into the land and say to the bulldozers, earthmovers, government and corporations, “thus far and no further.” If we do not, we shall later feel, instead of pride, the regret of Thoreau, that good but overly-bookish man, who wrote, near the end of his life, “If I repent of anything it is likely to be my good behaviour."

~ Edward Abbey