The Household

Outside of the weather the economy seems to be one of the most discussed topics.  Newscasters and commentators endlessly report and discuss the economic news of the day, which we carry into our thoughts and conversations. We fret about jobs.  We sweat out “the markets.”  We cheer positive economic news.  We groan over the negative.  We wonder about the security of Social Security.  We shake our fists at the national debt—a number most of us cannot fathom. Sitting at our kitchen tables, we pay bills and ponder budgets.  But what lies at the heart of this conversation, which seemingly touches every aspect of our lives?

                Discussions of the economy center around the production and consumption of resources, the wealth of the country, and the consequent effect on our lives.  Such focus renders us too distant from the core question:  what is the heart of the economy? What is the central concern?  The word “economy” originally came from the Greek, meaning household management.  The concern was how to care for the household, which begs a subsequent question:  Who constitutes the household?  Though few would realize it, an unlikely member of all our households is the American Bison.

                Defining who is a member of our household, and how we care for them are burning questions demanding answers.  So, what is our household? Our families and friends have intrinsic value, their worth simply abiding in their persons, since we attach sentimentality to them as persons.  Going beyond the limits of family and friends, however, others tend to take on a more utilitarian value. Their worth assessed more on how they fulfill our needs.  If people or things are not seen as a member of the family, or in our circle of friends, or do not carry any sentimental value, we tend to see them, if we see them at all, in utilitarian terms.  And if we do not perceive them as fulfilling any particular need, we tend to push them out of our consciousness, not even acknowledging they exist or have any particular value.  A member of a household, though, always holds value, both intrinsic and utilitarian, since even as a member of a household, we do fulfill some need for the other members.   The recent awakening to our inter-relatedness and interconnection to the environment has answered the “who.” Animate and inanimate existence upon the earth is interdependent.  All of us humans, along with the flora and the fauna, the air and the water, the soil and the rocks, constitute the household.  The notion of the isolated, rugged individual separated from the environment cannot be logically sustained. Even an isolated human being needs clean air and water, plant and/or animal matter, and a hospitable environment to survive.  

                 Until the late 1800s, the economy of the Great Plains and surrounding prairies was based to a large extent upon the American Bison.  The Native Americans of the region could not imagine their lives without the bison.  The buffalo were everything to them.  Pte (Lakota for buffalo) provided food, shelter, weapons, and even toys. The Pte Oyate (Lakota—buffalo people or nation) were, and still are, a spiritual connection to the creator, providing spiritually, materially, and culturally for the well-being of the plains’ inhabitants.  The bison were key to all life.  “If the buffalo live, everything else will live” [1].  The bison were central to the household of the Plains Indians.  And our recent understanding of the Great Plains ecology bears this out.  We have learned what the Native Americans already knew—the bison have ecological value, being a keystone species to the Great Plains [2]. 

                In today’s world, the bison are still a part of our household, both in intrinsic and utilitarian terms.  Examples of the former include the scientific value of studying bison, the emotional impact of viewing them, and their significance to environmental sustainability.  While for the latter, examples include national park attendance and the commercial value of bison meat production.

                The ecological value, though, has been diminished in favor of promoting beef and certain grains.  Cattle ranching and current farming practice monetizes the Great Plains and the Prairies, converting the land into one condition that maximizes meat and grain production [3].  Cattle and grain do not provide all the ecological values that the bison, which evolved with the Great Plains and the prairies, can fulfill [4].

                The current awareness of the interconnectedness of the flora and fauna within the Great Plains ecology has also proven the scientific value in studying the wild bison.  These studies have provided crucial information regarding predator-prey relationships, mechanisms of disease resistance, social relations of wild bison, etc. [5].  Insights gleaned from these studies aid our understanding of our place in the ecological scheme, and how we ought to act to protect the environment of our home, ensuring our own survival.  One element for the proper maintenance of our home requires an extended range of wild bison not to just increase our understanding, but to guide our preservation efforts [6].

                We also associate an emotional value with the bison.  Millions of people come to Yellowstone each year to take in the scenery but, additionally set their hopes on seeing wild animals; especially the buffalo and the wolves. In a 2016 study of visitors to Yellowstone 83% responded that wildlife viewing was their most important reason for visiting the Park [7]. Perhaps not everyone can verbalize the emotional impact of observing wild bison.  Still, we all do sense something stirring inside of us and feel some sort of connection to nature. The herds of bison inspire, instilling awe.  A feeling that we are part of something much bigger than ourselves finds a home within us.  Somehow we sense that if the buffalo were not here, we would be less than who we are.

                Attaching a monetary value to the emotional value of bison is difficult. So for those of us who want to think in utilitarian terms, and deal in cold, hard facts, here are the numbers worth considering.  First, in regard to recreational value, 4.5 million people visited Yellowstone National Park in 2016, spending $524.3 million, supporting 8,156 jobs.  The cumulative benefits of these recreational and emotional visitations amounted to $680.3 million [8], significantly contributing to the local economy.

An even more utilitarian consideration is the commercial value of bison meat production.  One thousand pounds of buffalo will produce approximately 300 lbs. of low-fat meat, which is healthier than beef.  Sale of bison meat averages $350 million per year with demand outstripping production capabilities, and providing consumers with a nutritional source comparable in protein to beef or chicken but higher in essential nutrients [9].  In these terms bison have greater worth to the household than cattle.

Bison Meat Comparison

                The debates over climate change, renewable energy, national debt, healthcare, and so on are really about one debate: Household management. The underlying issue revolves around who we consider as valued members of the household.  The ecosystem of the Great Plains and surrounding prairies occupy approximately one-third of the United States.  Prudence tells us if we are truly concerned about our well-being, then that ecosystem and its members, particularly the bison as a keystone species, are crucial to our household.  Whether we view the bison as having intrinsic value or utilitarian value, it cannot be denied Pte Oyate is a worthy member to be included in our household management.  The bison nation is, as sisters and brothers, aunts and uncles, mothers and fathers, grandmothers and grandfathers, contributing materially and spiritually to our well-being.

End Notes:

[1] Oglala Lakota Women and Buffalo. Featuring Charlotte Black Elk, Monica Terkildsen, Doris Respects Nothing and Katela Herekasapa. Miho Aida, Producer & Director. Retrieved from 11 Dec. 2019.

[2] See 26 April 2019 Post, “Dung Cakes and Feces Pie, Yum!”

[3] Fuhelendorf, S.D., B. W. Allred and R.G. Hamilton. 2010. Bison as Keystone Herbivores on the Great Plains: Can cattle serve as proxy for evolutionary grazing patterns? American Bison Society Working Paper 4:40pp.

[4] See 26 April 2019 Post, “Dung Cakes and Feces Pie, Yum!” and 26 May 2019 Post, “Bison Air Support.”

[5] Bailey, James A. 2013. 101. American Plains Bison: Rewilding An Icon.  Sweetgrass Books. Helena, MT.

[6] See 21 November 2019 Post, “Not Out of the Woods, Yet—Genetic Extinction (Part 3).

[7] Visitor Use Study 2016. Retrieved 01 Jan 2020.

[8] Tourism to Yellowstone National Park Creates $680.3 Million in Economic Benefits. National Park Service. Retrieved 11 Dec. 2019

[9] Current Status and Bison Perfected by Nature.  National Bison Association.  http:/  Retrieved 01 Jan. 2020.

The Real Old West

In our 30-second sound-bite, social media culture the phrase “the old west” may get confused for “Old Navy.”  But for those old enough or who have studied US History, the phrase may conjure images of cowboys, Indians, wagon trains, and gunfights.  But the period of the cowboys and cattle drives, the US Cavalry and plains Indians, gunfights and outlaws, only lasted one generation, from the end of the mid-1800s to the end of the 1890s. Nowadays, much of the prairies and plains are neatly arranged in arbitrary rows of corn and wheat, oats and soybeans, edged and dissected by ribbons of concrete and asphalt. The real old west, particularly from the Mississippi to the Rockies, the west in which the plains bison evolved, has a much larger and dramatic history; perhaps more than our feeble recollections can grasp. Understanding bison evolution depends on an awareness of the geological and environmental history of the “real old west.”

                From the mid-Cretaceous Period—145 MYA (millions of years ago) to 66 MYA—to the very beginning of the Paleogene Period (66 MYA to 23 MYA) the earth sported a shallow sea. Known as the Western Interior Seaway, it was located in the middle of what is currently the North American continent, roughly splitting that land mass in half.  

Western Interior Seaway

Hidden underneath the earth’s crusty surface, however, a great struggle was taking place.  The tectonic war that had begun since the earth’s infancy was pushing up stone giants to the west of the sea and tilting the seabed, sloping downward from west to east.  The result was the formation of the Rocky Mountains (80 MYA – 50 MYA), known as the Laramide Orogeny [1].  During this time, the sea drained revealing a soil-rich plain.

                However, the tectonic struggle was not the only force imposing its will on the North American land mass.  Cold and warm played a tug of war with glaciation advancing and retreating many times throughout the Pleistocene Epoch—2.6 MYA to 11,600 yrs. BP (Before Present).  During one of those glacial periods—the Mindel Glaciation lasting from 0.5 MYA to 125,000 yrs. BP—the  Bison genera  reached northern Eurasia and by way of the Bering land bridge (Beringia) two of the species spread into North America as far as present day Mexico [2]. 

The Bering Land Bridge-more appropriately understood as a plains between modern day Siberia and Alaska

Bison antiquus was most common in the southwestern US and Mexico, while Bison latifrons was found primarily north and inhabited a more heavily wooded or forested environment. B. Latifrons became extinct during the late Wisconsin glaciation (around 11,000 yrs. BP), while B. antiquus survived into the current Holocene epoch during which it evolved into the modern species of Bison bison consisting of two subspecies—B. Bison bison (Plains bison)and B. Bison anthabasca (Woods Bison)[3].

Bison latifrons
Bison latifrons
Bison antiquus
Bison Species Comparison—Modern day plains bison, Bison bison, is on far right (from

                Vegetation development and movements accompanied the withdrawal of the glaciers.  The general withdrawal began after 14,000 yrs. BP and most or all of the ice had disappeared by around 6500 yrs. BP.  During this time, within the region encompassed by the present day Great Plains and bordering prairies, forests and wooded areas were widespread with little open vegetation.  More open vegetation developed during the interglacial periods.

                The Holocene vegetation pattern developed in response to the general continental warming and drying trend that occurred between 11,000 yrs. BP—the end of the Wisconsin glaciation and the beginning of the current Holocene epoch—and 7000 yrs. BP.  The central grassland began to form during the very late Wisconsin glaciation and reached its maximum extent around 7000 yrs. BP [4].

  Meanwhile, the stone giants of the Rockies, sitting silently to the west, formed a rain shadow over the exposed ice-free former seabed, inhibiting needed rain from falling upon the western most regions of the vast plains.  The storm clouds that made it passed the rocky sentinels would not drop their precious cargo until further east.  Eastward from the Rockies the land slopes downward, while the rainfall follows an inverse slope. This factor is significant in the evolution of the grasses. Not enough rain was allowed for forests, but more than enough to prevent a desert.  The mighty forests, found further east, were denied.  Even bushes and shrubs were hard-pressed.  Of course, a lone tree or a small gathering of bushes here and there may have taken hold along a river or creek, but the land was to be ruled by grass, and aridity became the first and most implacable factor [5].

Rain Shadow (from Regional Professional Development Program,

 Closest to the majestic sentinels on the western horizon arose the short grasses while in the east where the dawn’s first light strikes, and the clouds are more willing to release their precipitation, arose the stately tall grasses. This aridity gradation drove the developmental effort of the grasses to be concentrated in the root structures, driving deep into the soil, holding the soil against an unrelenting wind sweeping across the plains.  Thus deep-rooted perennials, both of the short grass and tall grass varieties, took hold. Inextricably tied to the development of the open vegetation of this vast great plain was the evolution of the bison.  The Great Plains and the plains bison came into being together.

  Long before there were wagon trains and US Cavalry, cowboys and gunfights; long before Europeans were even aware of the North American continent, there existed a vast history of land and vegetation movements vying for dominance of a great region.  But it was not just a drama of earth and flora.  Old species of fauna disappeared to be replaced by new ones.  Humans were present as well—the ancestors of the Native Americans who, in this relatively new region, came to depend on one of the new species of fauna—the Plains Bison.  The Holocene Epoch is the real old west mocking our current understanding of the old west, and to which, our social media apps culture is not even a blink of the eye.

End Notes:

[1] The Laramide orogeny was a period of mountain building in the western portion of present-day North America.  This period started in the late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago.  The word “orogeny” is a geological term pertaining to the process of mountain making or upheaval (Webster’s Unabridged Dictionary).

[2] McDonald, Jerry N. 36. 2016. North America Bison: Their Classification and Evolution. McDonald & Woodward Publishing Co. Newark, Ohio.

[3]McDonald. 36.

[4] McDonald. 22-28.

[5] Manning, Richard. 3. 1995. Grassland: The History, Biology, Politics, and Promise of the American Prairie. Penguin Books.

Not Out of the Woods, Yet—Genetic Extinction (Part 3)

We all have issues.  The strategies and means employed to preserve the wild bison genome and promote genetic diversity is no exception.  As discussed in the previous blog—Not Out of the Woods, Yet—Genetic Extinction (Part 2)—several issues are involved in working toward these objectives.

Inbreeding and Genetic Drift:

The common strategy to avoid inbreeding depression and genetic drift is to create large herds.  It is estimated that herd sizes of 2000 to 3000 minimum are required [1].  Wild, free-ranging bison need to forage over large swaths of land.  For a herd size of 1000 animals it is estimated a land parcel of 100,000 acres or approximately 156 square miles would be needed [2].  Achieving the minimum herd sizes, then, would require land areas from 300 to 500 square miles.   For 500 square miles, this would be a square with each side having a length of 22.4 miles.  The only large conservation herd that meets both requirements for minimum herd size and land is the Yellowstone herd.  The herd of approximately 3500 roams over 3500 square miles [3].  However, much of that is mountainous and so does not represent the actual land available for exploitation by the bison, raising another issue—habitat requirements.  It is not enough that sufficient amount of land is acquired.  It must be terrain that can be exploited by the bison. 

Relatedly, especially where private lands are acquired, restoration of the terrain may be necessary.  Typically, private lands have been plowed-over and fenced-in for farming and ranching practices.  Any fencing has to be removed to allow for movement of the bison.  Other fencing, suitable for bison, has to be established along the perimeter of the reserve or refuge.  Any dams built to retain water for livestock would also have to be removed [4]. 

Then there is the issue of money [2].  The cost to acquire the necessary land and place a herd of 1000 onto that land may run well over $ 1 million. Reaching the minimum requirements to preserve and promote the bison genome could then run $2 to $3 million per herd. Significant funding raising efforts will be needed.

So what land is possibly available?  Bailey concludes that land east of 98 degrees longitude—Minnesota, Iowa, Missouri, eastern Oklahoma, eastern Texas and all points east—is  too fully developed to allow for the necessary land areas.  Between farmland and cities is there is no land parcel large enough to support the minimum herd size.  This leaves the plains—lands west of 98 degrees west longitude to the Rocky Mountains—available.  Perhaps some parts of Nevada and Oregon could be utilized [5].  There are still large tracts available in this region to promote such herds.

Cattle-Gene Introgression:

A potential problem has been identified in regard to purifying bison herds of cattle-gene introgression.  Removing bison with cattle genes may inadvertently remove genes of common ancestry.  Authors Kathleen O’Neal Gear and Michael Gear [6] raise the question: Did bison interbred with any prehistoric species of the Bos side of the Bison-Bos family, and if so, is this the source of the cattle genes?  No one really knows. Removing bison having only genes from domesticated cattle requires the DNA testing to differentiate between those genes belonging to both cattle and bison ancestors from genes belonging only to domesticated cattle.  This would require a complete mapping, or sequencing, of the bison genome [Gears], which to date has not been performed.  Except for the Yellowstone and the Henry Mountains herds, and more recently the American Prairie Reserve herd, all bison most likely have at least some cattle genes.  Derr has found cattle genes in approximately 64% of US federally managed herds [7].

The Gear position, though, does not address the cross-breeding that did take place on private ranches in the US and performed by the Canadian government into the 1960s. There is no doubt the cross-breeding occurred and a few studies have suggested that introgression has been detrimental to bison [8].

Purifying the herds of cattle-gene introgression along with the movement to list wild bison under the Endangered Species Act presents another potential issue if such listing would succeed, according to the Gears.  Some are arguing that the scarcity bison without cattle ancestry qualifies wild bison as an endangered species.  Under the ESA the sale or transporting of bison free of cattle genes could be punishable by a $50,000 fine and one year in prison per charge.  Ranchers or farmers owning bison without cattle ancestry could find themselves being charged under the ESA if they would try to sell or move their bison.  The argument to list wild, pure, bison as endangered, then, could lead to conflicts with current legal definitions governing the status of bison. 

Yet, legal recognition of plains bison as wildlife is required if the wild genome is to be restored on federal lands.  But this seems unlikely at this time.  Most states do not recognize wild bison (see March 2019 post, Legal Status of the American Bison), and the federal government will not restore wild plains bison without support from the affected states.  This could change if the Fish and Wildlife Service would recognize the threat domestication represents to the wild genome, and lists the plains bison as a threatened or endangered species [9].

In any event, the greater goal is to restore wildness to the bison genome.  Reducing cattle-gene introgression to low levels and letting nature takes it course, may over time swamp the cattle genes.  Achieving absolute purity may not be needed if the other actions to promote the wild genome are taken [10].

Artificial Selection:

Purifying the conservation herds of cattle-introgression, though, is not enough to preserve the wild genome and promote genetic diversity.  Artificial selection, caused by human intervention, must be minimized as much as possible.  The complete elimination of human intervention may not be feasible.   No matter how large the land parcel may be, fencing will still be required to keep bison out of private lands.  Handling, needed for testing, culling and transporting of animals, will also be involved in implementing the other objectives. 


Various mechanisms threaten the existence of the wild bison genome, requiring various strategies to thwart the threat.  These strategies and their implementation, however, present conflicting objectives, which may require trade-offs, and issues, which demand solutions.  But the restoration of the wild genome and the promotion of genetic diversity cannot wait until all issues have been fully resolved to all interested parties’ satisfaction.  Fortunately, efforts are proceeding to realize the necessary objectives (e.g., The American Prairie Reserve, the Buffalo Field Campaign, etc.) while work continues to resolve the obstacles still in the way.

End Notes:

[1] Hedrick, Paul W. “Conservation of Genetics and North American Bison (Bison bison).” Journal of Heredity 2009: 100(4): 411-420.

[2] Heidebrink, Scott, Bison Restoration Manager, American Prairie Reserve.  Email to author 03-Oct-2019.

[3] Bailey, 180. Baily, James A. 2013. American Plains Bison: Rewilding an Icon. Sweetgrass Books. Helena, MT.

[4] American Prairie Reserve Bison Report 2016-2017.  Retrieved 10-Oct-2019 from  Also, Bailey, 207.

[5] Bailey, 207.

[6] The Gears are well-known authors of over 50 novels.  They may be best known for their People of the Earth series.  In addition to writing novels, they raise bison.

[7] O’Neal Gear, Kathleen and Gear, Michael W. August 2010.“Bison Genetics—The New War Against Bison.”

[8] Geist, Darrell, Habitat Coordinator.  Buffalo Field Campaign.  Email to author 19-Sep-2019.

[9] Bailey, 220.

[10] Bailey, 214.

Not Out of the Woods, Yet—Genetic Extinction (Part 2)

The mechanisms by which genetic extinction of the wild bison genome may occur were described in the September post.  If the prevention of loss of genetic information and the promotion of genetic diversity are to be achieved, how should we proceed?  What avenues are available or can be created? Broad objectives were laid out in the Vermejo Statement (see the Feb. 27, 2019 post From the Brink to the Foothills-Part 2).  More recently Paul Hedrick has laid out more specific objectives.  These include:

  • Keep cattle ancestry at a very low level,
  • Avoid inbreeding and artificial selection for livestock-related traits, and
  • Retain sufficient genetic variation for future adaptation.

Achieving these objectives requires a variety of strategies.

Cattle-Gene Introgression:

The greatest focus of conservation genetics has been identifying herds with cattle ancestry, since the efforts to restore the wild bison have been threatened by domestic cattle introgression.  Reduction of cattle-gene introgression involves several approaches because of various circumstances [1].

The popular tenet from the medical profession—Do No Harm—applies here as well.  The first and most logical strategy is to not introduce bison with known cattle ancestry into herds free of cattle  introgression.  Though this seems to be the easiest approach, there are only a few herds known to be free of cattle ancestry—e.g., the Yellowstone herd, the Henry Mountains herd, and more recently, the American Prairie Reserve herd.  This approach only protects these herds until other herds free of cattle ancestry can be established.  It should be noted the notion of cattle ancestry free is relative.  There may always be the presence of cattle genes.  Additionally, the complete eradication of cattle genes may not be desirable since the genetic testing has not matured enough to differentiate between genes unique to domesticated cattle and genes having common ancestry to bison and cattle (This issue will be explored in more depth in part 3).

A corollary to the above strategy is to introduce bison without cattle ancestry into herds with cattle-gene introgression.  The benefits could possibly include: a decrease in inbreeding depression, an increase in genetic variation, and genetic swamping of cattle ancestry. This would dilute the presence of cattle genes to the point at which natural selection would eventually take over and reduce the effects of cattle ancestry. A variation of the introduction of cattle-gene free bison strategy involves starting new herds.  

Another approach regarding cattle ancestry involves translocation of bison between herds with similar levels of cattle-gene introgression.  This, at least, would not raise the overall level of cattle ancestry, but would have the benefit of avoiding inbreeding depression.  But this requires more accurate tests to estimate the level of introgression and further examination of potential phenotypic effects [2].

Finally, culling may be used to reduce mitochondria DNA (mtDNA) and specific nuclear alleles (one of two or more alternative forms of a gene found at the same place on a chromosome) of cattle ancestry.  Culling involves separating out the undesirable animal with the objective of reducing or eliminating the traits, qualities or disease of that specific animal from the herd.  Undertaking this strategy to reduce the mtDNA, however, incorrectly assumes this also reduces nuclear DNA.  Care needs to be taken to retain variation at the nuclear level, requiring more extensive and accurate testing.  And culling to reduce specific nuclear alleles is also problematic. Unfortunately, this action will most likely have other alleles associated with the cattle ancestry remaining at other unidentified genetic regions [3].

Inbreeding and Genetic Drift:

Inbreeding and Genetic Drift are significant issues.  Most of the conservation herds are relatively small (i.e., less than 1000). Under these circumstances maintaining the genetic information and diversity required to promote the wild genome is difficult if not impossible.  To avoid these processes of genetic extinction, herd sizes of at least 2000 to 3000 are needed [4].  Out of the 44 conservation herds, only 10 herds have more than 400 animals, and out of these, only 4 have more than 1000 bison—Yellowstone National Park, Medano Ranch, Co., Tallgrass Preserve, OK, and Custer State Park, SD).  The herds smaller than 400, are most definitely, losing genetic diversity, and in danger of inbreeding.  Six of these herds are being managed as a meta-population with exchanges of animals.  This practice may alleviate some inbreeding but will not prevent loss of genetic diversity.  Only the Yellowstone herd is large enough (3000 to 4000) to limit that loss [5].  In addition to the four conservation herds mentioned above, the American Prairie Reserve [see link to the American Prairie Reserve’s website in the Favorite Links section of this blog] in Montana has a herd which is currently slightly less than 1000. 

The regular exchange of bison between herds is another method to avoid inbreeding and genetic drift. In moving bison to other herds, though, consideration must be given to disease control, handling practices, and state laws.  Animals would need to be tested prior to transfer to ensure diseases such as brucellosis and tuberculosis would not be transferred.  Handling of bison is difficult.  Care would be required to ensure the safety of the animal, not to mention the personnel involved.  Finally, laws defining the status of bison differ from state to state and would have to be taken into account.

Achieving genetic diversity requires ongoing assessment of genetic variation from which strategy decisions can be made.  In this regard, Hedrick offers several recommendations which are beyond the scope of this post [6].

Artificial Selection/Domestication:

A certain amount of human intervention in conservation herds cannot be avoided.  Even in Yellowstone the herd suffers from human management—the herd size is limited, the herd has been vaccinated, the average age of the herd has been artificially reduced, and  access to seasonal ranges has been restricted [7].  And this is the most “wild” bison we have!

Herd sizes are managed through random culling with the first animals coming through the chute being selected.  It has been observed, though, the largest animals are usually the first.  Bison traits, then, associated with large body size are being artificially selected out.  Thus, even random culling can have a negative effect on natural selection.  Culling along with vaccination is also used for disease control.  However, disease control treats low resistance bison equally with high-resistance bison, preventing natural selection from promoting bison with high-resistant immune systems. Intervention to control disease, then, tends to retain susceptible animals [8].  If the wild genome is to be encouraged, culling to limit herd size and efforts at disease control must be either eliminated or be rare and minimal.  Still, culling to reduce herd size may be necessary due to land and carrying capacity [9].

Keeping human intervention at a minimum is not enough.  As has been found with the re-introduction of wolves in Yellowstone bison have had to relearn their defensive traits. Avoidance of loss of defensive traits will require the introduction of the bison’s natural predators—the wolf and the grizzly. Predation is also a natural selective force. 


The various genetic extinction mechanisms and the circumstances in which bison find themselves—large herds, small herds, land issues, etc.—require several strategies to prevent genetic extinction and promote genetic diversity. The American Prairie Reserve’s bison management approach is a good example of the implementation of some of those strategies discussed above:

  • Their overall goal is to achieve a herd size of 2000 to 3000 within the next 5 to 7 years
  • Their approach is “hands-off” as much as possible. 
  • Manipulation of bison population is minimized to allow for the development of natural sex ratio and age structure
  • Mortality from bull competition, predation, and other natural events is permitted (However, no wolves or grizzlies are currently present on the Reserve)
  • Continue to secure more land and habitat to support the herd and allow for continuous grazing
  • Ensure new bison introduced into the herd are free of cattle-gene introgression [10]

Implementing these strategies involves answering many questions. For instance, land is perhaps the most significant issue.  The common strategy to address the extinction mechanisms is to create large, free-ranging herds, requiring large amounts of land.  But not just any terrain will do.  The habitat must support large swaths of grazing land. How much land is needed for a large herd of free-ranging bison?   What needs to be done to prepare the habitat? Are there state and/or federal regulations involved?

Another concern involves genetic testing.  Ridding herds of cattle genes may cause the loss of common ancestry genes.  How do we differentiate?

If predation is to be re-introduced, what is required to make that happen?

These issues need to be worked out, and will be pursued in part 3 of this discussion.

End Notes:

[1] Hedrick, Paul W. “Conservation of Genetics and North American Bison (Bison bison).” Journal of Heredity 2009:100(4): 411-420.

[2] Phenotypic Effects—Effects on an organism’s observable characteristics or traits and covers the organism’s physical form and structure, developmental processes, biochemical and physiological properties, behavior and products of behavior (Wikipedia).

[3] Hedrick.

[4] Bailey, James A. 2013. American Plains Bison: Rewilding an Icon. Sweetgrass Books. Helena, MT. 179. and Hedrick.

[5] Bailey, 179.

[6] Hedrick.

[7] Bailey, 140.

[8] Bailey, 142-145.

[9] Carrying Capacity—the ability of a habitat to sustain a population (Bailey, 87).

[10] Retrieved 02-Oct-2019 from Also, email to author from Scott Heidebrink, Bison Restoration Manager, American Prairie Reserve. 03-Oct-2019.

Not Out of the Woods, Yet–Bison Genetic Extinction

The topic of genetic extinction of the wild bison genotype is rather extensive.  So, the plan is to discuss this issue in several parts, beginning with the mechanisms contributing to the loss of genetic information. Then follow with an exploration of how to avoid those mechanisms and a review of particular issues involved.

Part I: Mechanisms

Imagine a river running endlessly in both directions (nevermind the logical inconsistency) with only one bridge crossing the river, the only means to the other side. Furthermore, coming up to that bridge is a 12-lane highway, but the bridge only permits one lane with no merging lanes allowing access to that one lane.  Instead the other 11 lanes all end with a wall at the river’s shore.  But this is unknown until the ends of those lanes are reached.  Only those traveling on the lane accessing the bridge are able to cross the river.  This situation presents a bottleneck.  By the 1900s the North American bison entered a genetic bottleneck.   From a population of many millions only less than a 1000 were able to cross over our imagined bridge.  A genetic bottleneck occurs when a population is reduced to a small subset of the original population.  The last remaining individuals, then, represent the remaining genetic heritage of the entire initial population. But they do not represent the overall genetic diversity of the population before the bottleneck.  Such circumstances are detrimental to the viability of a species because of the loss of genetic diversity [1].

                Other than out-right extermination of a species, Bailey has identified five processes contributing to the genetic extinction of the wild bison genotype [2]:

  • Founder Effects (Initiating herds with few individuals having limited genetic diversity)
  • Genetic Introgression (Crossbreeding with cattle genes–hybridization)
  • Inbreeding depression in small herds
  • Genetic drift in small populations
  • Artificial selection by human intervention (domestication)

Before going further the concept of wildness needs definition.  According to Bailey, wildness refers to the impact humans have on an animal population or an ecosystem.  A species or an ecosystem is considered wild if it exists and functions with no human intervention [3].  Of course, in the case of bison, Native Americans have interacted with the bison.  But perhaps it could be argued their intervention had no more impact than that of natural, random events; certainly not the impact our culture has had. 

Founder Effects:

Founder effects involve initiating herds with few individuals. Today’s herds have been initiated with the few bison left from the slaughter that took place in the latter half of the 19th century.  Because of this, and as illustrated in the thought experiment above, with the loss of genetic diversity the potential for effective natural selection has been reduced.  In addition, with few founders the stage is set for other resulting mechanisms contributing to genetic extinction—for instance, inbreeding depression and genetic drift experienced in small herds.

Genetic Introgression and Hybridization:

Bison were saved from extinction primarily by 5 ranchers and the small remnant in Yellowstone National Park.  The ranchers during the end of the 19th century and early 1900s experimented with crossbreeding bison with cattle in an effort to raise a hybrid for meat production.  This endeavor quickly ended since bison-cattle hybrids almost always resulted in female offspring and no viable male offspring.  Hybridization that results in one sex being absent, rare or sterile indicates evolutionary incompatibility between the two species [4].  Even though hybridization was a dead-end, the attempt introduced cattle genes into bison herds, known as genetic introgression. Many of the bison from these early hybridization efforts were used to initiate or grow other herds, injecting traits related to domestication into the bison herds and effecting physiology.  One study by Derr found bison with cattle-gene introgression tend to be smaller at an early age and never grow as large as more pure, wild bison [5].


Inbreeding involves the breeding of closely-related individuals and occurs in small herds or in herds maintained with few bulls [6], limiting the genetic diversity. Bison bulls will mate with as many cows as is possible, and dominant bulls will father more calves while less dominant bulls may not father any calves [7].  In small herds the genetic material of the dominant bulls will tend to be concentrated and passed on with genetic material of others bulls lost. The negative effects of inbreeding replace natural selection in determining the future genetic make-up.

Genetic Drift:

A change in the relative frequencies of alleles (one of two or more alternative forms of a gene found at the same place on a chromosome) is known as genetic drift. This process occurs in a population due to random events during survival and reproduction [8]. Random chance determines which genes or animals survive and reproduce, causing genetic change in a population.  For instance, a bison could break through the ice when crossing a river and drown. But the major source of changes in allele frequency lies in reproduction during the production of ova and sperm.  When ova and sperm are formed in cell division, chromosomes split leaving the reproductive cells with only half the chromosome set. Thus, during reproduction some alleles are discarded both from the bull and the cow. In large populations random events effects are relatively unimportant because opportunities are present for natural selection to work, mitigating any loss of genetic information. However, in small populations genetic drift may cause some genes to disappear, reducing the genetic diversity and evolutionary potential [9].

Artificial Selection—Domestication:

Domestication results from the replacement or weakening of natural selection by artificial, human-managed selection.  Thus domestication is eradication of wild bison by modification. For example, aurochs were continually domesticated eventually leading to modern domesticated cattle.  These efforts were so extensive aurochs no longer exist.  The essence of selective breeding involves humans deciding which individuals will produce the next generation which will better serve human goals [10].

One of the goals involves handling. Wild bison are difficult to handle, causing harm to the animal, causing potential damage to shoots and pens, and involving more time and effort on the part of the ranchers.  To mitigate handling issues, bison ranchers and farmers have found that by increasing the level of serotonin and lowering the levels of dopamine bison become more docile.  Over time selecting those animals with increased serotonin and lower dopamine for breeding will artificially select the more manageable bison, moving from wildness to domestication. 

Additionally, since ranching and farming are bottom-line businesses, each bison is seen as a productive unit.  Under this perspective management of bison will increase the number of cows altering the natural sex ratio. Bulls can breed many cows, whereas a cow will only have one, possibly two calves per year. Maximizing the commercial herd requires few bulls but many cows.  Besides, cows are also easier to handle than bulls. A biased sex ratio shifts the breeding behavior.  Cows that do not incite competition between bulls will more likely be bred.  Thus the traits associated with competition between bulls become artificially selected out.  Unfortunately, this management perspective not only occurs with private herds.  Public herds are seen as a revenue source, and consequently, subjected to the same practice [11].

               Given the above mechanisms pushing us toward the genetic extinction of wild bison, the question becomes:  how do we mitigate or prevent these processes?  Complete avoidance may not be possible. The means and objectives involved may be in conflict with each other and may require trade-offs.

Prevention and mitigation of the genetic extinction mechanisms contributing to the loss of wildness in bison will be explored in the next post.


[1] Bison Bellows. Retrieved 09-Sep-2019 from

[2] Bailey, James A. 47.  2013. American Plains Bison: Rewilding an Icon. Helena, MT. Sweetgrass Books.

[3] Bailey, 73.

[4] Hedrick, Paul W. “Conservation of Genetics and North American Bison (Bison bison)”. Journal of Heredity 2009: 100(4): 411-420.

[5] Bailey, 48.

[6] Bailey, 76.

[7] Lott, Dale F. 194. 2002. American Bison: A Natural History.  Berkeley. University of California Press.

[8] Bailey, 78.

[9] Bailey, 49-50.  Also for a full discussion of genetic drift see Bailey, 78-80.

[10] Lott, 196-198.

[11] Lott, 198-200.

Bison Romance

During North America’s early spring, a reddish-orange creature emerges.  Within minutes of its appearance, the newly-born bison calf rises and begins expending pent up energy.  Its movements constantly watched over by its mother, the largest animal on the North American continent.  Colloquially known as a “red dog,” this little beastie weighs in from 30 to 70 lbs [1] upon its debut, a far cry from its future weight (approx. 2000 lbs for males and 1000 lbs for females), easily attained within a couple of years.  Some may consider this newly arrived entity as “cute.”  They would be deceived.  For this “cute-ness” scampering around in the spring air will transform into potentially the greatest source of animal-induced injuries to humans in North America.  It will scoff at bears, coyotes and mountain lions.  Oh my!!  Of course, wolves are a different matter.  Hunting in packs, they can take down an adult bison. So what is the origin of this “cute” beastie?

Bison Calf – “The Cute Little Beastie”

                Its genesis begins slightly more than 9-1/2 months [2] prior to its emergence. During the summer months of July or August romance rumbles and shakes the earth.  The females of the species begin to gather with the up-until-now aloof males straggling in from their own groups to join the females.  Before now, the bulls do not communicate much with other bison.  Prior to the breeding season, they are usually off on their own or in small groups, being content to graze.  However, with the onset of the breeding season, the rut, the bulls become more communicative.  One may believe only courtship of the female occurs during the rut.  But the male has a tough job ahead.  He not only has to win the attention of a receptive female, but he also has to manage other bulls.  The bull will seek out a female and stay with her.  This behavior is called tending.  While doing so, he must also ward off other bulls by fighting and threatening.

                Males will vie for the females.  Even though a bull is tending a cow, it is not entirely a foregone conclusion this will be the mating pair.  Other bulls may threaten to replace the tending bull.  The one who dominates will take over the tending, but will then also have to ward off anxious bulls looking to mate. But fighting requires much energy which is also required for breeding.  So, the bull will generally threaten first in order to conserve energy.  Threatening may begin with bellowing, a sound the bull makes, which to the undiscriminating ear, may sound like thunder off in the distance.  The intruder may also bellow in return, and if the bellowing competition escalates, as typical of males, the sounds become louder and the bravado more expressive.  During the bellowing, the bulls may paw the ground or wallow [3] [4]. Bison often will lie down in a barren depression and role back-and-forth, throwing up dust.  Though there are other reasons as well for this behavior, it is often used in the bull’s threatening behavior.

                During challenges, wallowing may also engage a strange phenomenon. But males of other species sometimes exhibit bizarre behavior when attempting to win over the female as well — nothing really new here.  A threatening bull may urinate in a wallow and then roll in the moist ground.  The reason is not fully understood.  Dale Lott, a naturalist, speculates the testosterone level is being signaled to the challenging bull.  As the bull uses up physical resources, muscle begins to metabolize with the metabolites entering the urine, which can be detected by the conditioned nose of the challenger.  The opposing bull will know if fat is still being burned and if muscle is still intact [5] of the threatening bull, allowing the opposition to determine if he has the resources to continue the fight against the threatening bull.

Bison Wallowing

                If bellowing and wallowing do not work, then the males will begin to posture.  There are two types of posture: head-to-head and broadside.  Head-to-head posture precedes a charge in which the two bulls will run straight at each other.  As they approach one another, either one or the other may submit by turning  away or they will bang heads.  If they approach slowly, they will engage in a behavior called “nod-threatening”.  The two bulls will stand close enough to each other to reach the other with their horns by turning their heads aside.

                In the broadside posture the bull will keep himself broadside to his opponent and raise his head a little as well as arch his back and bellow.  The idea is to show he is not to be messed with.  However, this posture usually does not lead to a fight.  The broadside and the nod-threatening postures demonstrate the lengths bulls will go to forewarn each other.  The issue is efficiency.  Perhaps even more than offering protection to the herd, producing calves is the bull’s prime directive.  Breeding requires energy, and the bull, instinctually driven, attempts to mate as much as possible to produce  as many calves as possible.  Fighting seriously reduces the bull’s energy.  Further, fighting and breeding burn up fat and muscle mass, which have to be replaced between the end of the rut, which may last into September, and the onset of winter if the bull is to survive the winter [6].

Bulls Going Head-to-Head

                Before the tending of the female and the subsequent efforts to win his prize, the bull first selects a female.  Cows come into heat sometime during the rut, and will only be in that state for about two days.  Cows only release one egg at a time.  Achieving fertilization requires attracting a suitable mate and be willing to mate, which means changes for the cow.  When she comes into heat, the vulva becomes swollen and oozes mucus and lymph, signaling to the bull she is ready to mate.  The bull will wander through the herd inspecting each cow to determine which ones are ready to mate.  After inspecting, the bull may curl his lip.  Lip curling is a complex expression.  The bull stretches out his neck, holds his head level, distends his nostrils and curls back his lips.  This occurs after examining the cow’s vulva or sniffing her urine [7].  The cow’s urine will indicate how close she is to ovulation.  The bull detects this through the vomernasal organ, which has an opening in the roof of the bull’s mouth.  This organ seems specialized for analyzing the female’s urine [8].

Bison Lip Curling

                Often the cow rebuffs the bull by the swing of the head, a thrust of horns or sometimes just a good swift kick. After selecting a cow, and if the bull has not been dissuaded, the courting begins.  During courting, the bull stands parallel to her side, warning off intruders which may even include the cow’s previous calf or yearling.  The pairing may last only a few minutes if a more dominant bull intrudes and displaces the tending bull.  Or the pairing could last one or two days.  In either case, the tending bull will move on to another cow, being driven by the bull’s prime directive.

Even though the bull may seem dominant, but the cow rules the courtship. Typically the bull follows behind her.  If he tries to direct her in a particular direction, she can easily dodge him and wander off on her own.  He is resigned to follow her.  Eventually, the herd leaves the pairs behind.  The cow may try to rejoin the herd, but the bull will move to block her, which she can easily evade. Or she may also go for a higher ranking male.  She, too, has a prime directive to breed the best calf.  After all, she only has one shot each season.  So she must choose wisely, and is more receptive to older bulls who have survived winters, predators, disease and battles.  Older bulls have been tested and have been found worthy.  If, however, she stays, she has chosen him.

The bull utters brief panting sounds as he approaches the cow, warning her.  First advances are typically repelled but the bull will be insistent.  His intentions are made known by standing and swinging his head.  Eventually he will attempt to put his chin on her rump, which, in response, she will evade.  He may try to climb upon her, only to have her slip out from under him.  But once receptive, the cow will allow the bull to mount.  He uses his chin as leverage to lift himself onto her rump, leaning his head against her side and pressing his forelegs around her.  After insertion, the thrusts last only 4 to 10 seconds.  Then he either drops off or releases his forelegs so the cow can walk out from underneath him.  The copulation may harm the cow.  Her flanks may have bloody wounds from the bull’s front hoofs striking and rubbing her. The moment of copulation usually attracts the attention of younger males who will follow the couple afterwards.  But the tending bull will stay with the cow, warding off other suiters to prevent them from also mating with her.  This ensures the tending bull’s seed is successful fertilizing the egg and not replaced by the seed of another.  Eventually though, the tending bull will move on to attempt to mate with other cows [9][10]. 

Bison Mating

Nine and-a-half months later, the fruition of the bison romance occurs, as a reddish-orange little beastie emerges.  Upon birth the cow licks, pulls away and even eats the membranes entangling the calf.  After disposing of these membranes, she licks the slimy wet coat of the newborn.  Meanwhile oxytocin, a pituitary gland hormone, has flooded her brain stimulating her endearment of this new creature, which she will nurture and protect [11]. If the cow is only three years old, then this is most likely her first calf.  Females breed when 2 years old and have their first calf at 3 years old.  Cows can live 20-25 years, having a calf each year [12]. 

The cycle completed, the newborn “red-dog”, if male, will repeat the fine tradition of seeking and tending a female, threatening and fighting challenging bulls, and mating with as many females as possible.  If the little beastie is female, she will enter into the honored role of controlling the mating process and producing off-spring, and nurturing the next generation.  And so the cycle continues, sustaining the herd and ensuring the survival of the species.

End Notes:

[1] Retrieved from

[2] The average gestation period is 9-1/2 months.  Retrieved from 5-Jul-2019.

[3] McHugh, Tom. 1972. The Time of the Buffalo. University of Nebraska Press. 191-195.

[4] Lott, Dale.  2003. American Bison: A Natural History. University of California Press. Berkeley. 14-18.

[5] Lott. 9.

[6] McHugh. 192-193.

[7] Lott. 15.

[8] Lott. 20-21.

[9] McHugh. 192-195.

[10] Lott. 15-17.

[11] Lott. 29.


Brucellosis: Crying Wolf?

Just north and outside of Yellowstone National Park, deep snow covers the ground and bitter March winds blow through the pines. Because of the adverse winter conditions in the Park, the bison have had to seek better grazing. Following the easily traveled snowmobile trails, they have wandered out of the harsher conditions of the late winter park.  Using their heads to plow away snow to uncover the buried grass, a small group of bison graze.   Only the crunching of the snow under their hooves, the occasional snort of exhaled breath, and their rhythmic breathing along with the occasional bird song and the moaning of the pines swaying in the wind can be heard.  Suddenly, a shot rings out!  A bison cow goes down!  Then another shot and another!  Two more cows are hit.  One stumbles and then drops.  The other runs back toward the park bleeding profusely.  The rest have already bolted for the safety of Yellowstone.  The wounded one makes it back to within the confines of the park, but has stopped, exhausted, drained.  She tries to take another step in the deep snow, but cannot.  She lies down and slowly dies.  No one comes for her.  A few days later, her scavenged carcass will be found.  Back at the killing grounds, the hunters are celebrating.  They have thwarted another incursion of the feared bison onto the bison’s natural grazing habitat.

            So why fear the bison outside of Yellowstone Park?  They do not attack humans or other animals unless they feel threatened. They do not devastate the land as they graze. So why such hostility toward them as illustrated above, which is a fictionalized account of what has happened and continues to happen.  Bison roaming outside of the Park into Montana are either hazed back into the park or killed.  Hazing involves rounding up the bison and herding them back into the boundaries of Yellowstone or into a quarantine pen, which inherently causes trauma for them.  But herding of bison is difficult.  Killing is easier.  But why slaughter an animal carrying the last known wild bison genome?

            The Montana ranchers claim bison threaten the cattle herds with the disease brucellosis.  Brucellosis, a bacterial infection (B. abortus), causes abortions and still-births in cattle, bison, elk, bear, deer, etc.  If a brucellosis outbreak would occur and spread through a cattle herd, financial devastation could result for the rancher.  As a side note, any losses, ironically, would be covered by government subsidies. 

            Upon closer examination of the circumstances and history of brucellosis in bison, the claim of the ranchers and the Montana Livestock industry strike one as a smoke screen.  One would think that science should be driving the claim, but politics and profits seem to be the drivers.  The USDA has threatened the state of Montana with the loss of Montana’s brucellosis-free status, which permits shipment of untested cattle across state lines.  The loss of such status means the ranchers would have to pay to have the cattle tested prior to shipment, which incurs additional costs. To ensure no risk of cattle infection the eradication of brucellosis has taken on a zero tolerance approach, giving absolute priority to achieving a zero risk level for cattle infection [1].  In addition, since almost no brucellosis can be found in American cattle herds, the USDA has expanded its efforts to eradicate the disease. The US Dept. of Agriculture has turned its attention to eradication of brucellosis in wild animals.  Thus, agencies whose funding depends on the USDA are recruited into the cause [2].  The eradication of brucellosis has become politicized with agencies increasing their power and funding by joining the crusade to rid the wild animal population of brucellosis.  The crusade, of course, includes the method of slaughter as well as vaccination.  However, the slaughter only seems to be restricted to bison; other wild life are not included. The slaughter of the Yellowstone bison arose, then, out of fear and political expediency, not science.

            Brucellosis probably arrived with infected cattle imported by Spanish settlers into Mexico.  Sometime prior to 1917 infected cattle were introduced into the Greater Yellowstone Area [3][4] with the disease spreading to the bison.  But the transmission of brucellosis from bison to cattle has never been established.  The actual transmission path would have to be through the ingestion of infected birthing materials or from an aborted fetus.  Thus, bison bulls, calves, yearlings and non-pregnant bison cows would not pose a threat. Furthermore, infected pregnant bison females will only pass infected material in her first pregnancy since after the first pregnancy, the uterus develops protection, preventing infected material being shed in subsequent births [5]. 

In order for brucellosis to be passed on to cattle cows, the cattle cows would have to lick or eat the discharged reproductive debris.  But bison abortions or still-births are rare.  If they do happen, the most likely time is winter when cattle are not present.  Cattle are unable to withstand bitter winters and are not grazed near Yellowstone until June.  By this time, the bison would have returned to the park [6].  But even should there be aborted or birth materials in June or later, the brucellosis bacteria cannot survive warm weather or direct exposure to sunlight.  Besides, predators and scavengers would all but guarantee fetuses or infected reproductive material would not persist beyond mid-May [7]. Thus, the possibility of cattle cows contacting infected material is remote.

Recent studies have shown that bison are not the primary reservoir of the brucellosis bacteria.  The bison were once considered to be the primary source because of high levels of B. abortus.  But examining the extent and transmission characteristics in other wildlife has shown elk to be the primary source of B. abortus.  Even though elk have a lower level of B. abortus, they are more numerous and widespread than bison.  Bison rarely move outside of conservation areas and are subject to rigorous management practices that limit migration, making comingling with cattle almost impossible.  In contrast, elk are allowed to freely range, and make long-distance migrations between summer and winter grounds, increasing the probability of contact with livestock.  Genetic studies have confirmed this, demonstrating elk to be the likely source of infections, not bison [8].  This begs the question: Why are elk, the primary source of brucellosis infections, allowed to roam free and bison are not?  The revenue generated from elk hunting may have something to do with it.  Revenue from elk hunting activities amounts to approximately $11 million annually for the state of Montana alone [9].

            Hazing and killing of bison that have roamed outside of YNP are not the only methods employed to placate the fears of the ranchers. With the state of Montana and the USDA insisting, bison are periodically rounded-up and tested.  About 45% of the bison test positive for long-term antibodies.  Using a positive test as proof of infection, the bison is slaughtered.  But another test is performed after the bison has been killed to determine if actual bacteria are present.  Comparing these two tests reveals a drastic difference.  Very few slaughtered bison have the actual bacteria.  The bison, then, are being slaughtered simply because they have developed immunity to brucellosis [10]. The control of brucellosis is a “no holds barred” approach when it comes to bison. Of course, the slaughter includes both bulls and cows. But why slaughter the bulls who cannot transmit the disease, and are essential for breeding? The logic to the slaughter remains elusive unless it is understood as arising from an unjustifiable fear.

            In response to the brucellosis eradication efforts in bison a number of viable solutions have been offered.  The Buffalo Field Campaign ( has offered several. These include:

  • Develop herd management plans that adjust cattle grazing dates which would eliminate transmission potential;
  • The Greater Yellowstone Area could be exempted from the OIE certification process by keeping cattle out of the area.
  • The state of Montana could develop risk management strategies for domestic cattle that allow free roaming bison [11].

            In light of the evidence–genetic studies, the migration and grazing habits of bison, the elk herds as a primary brucellosis reservoir, the transmission dynamics, and the testing results—and the offered solutions, why does the slaughter of the bison continue? Based on the above, it appears to be a result of the efforts of the livestock industry in Montana to maintain political control, using the fear and the paranoia over brucellosis as the means to maintain that control.

[1] Lott, Dale F. 2002. American Bison: A Natural History. University of California Press. Berkely, CA. 111

[2] Callenbach, Ernest. 1996. Bring Back the Buffalo: A Sustainable Future for America’s Great Plains. Berkeley. University of California Press. 281-283. These actions of the USDA continue to this day.  Confirmed by Darrell Giest, Buffalo Field Campaign, in an email to the author dated 15-April-2019.

[3] Callenbach. 134-139

[4] Kamath, Pauline L., Foster, Jeffery T., et. al. Genomics reveals historic and contemporary transmission dynamics of a bacterial disease among wildlife and livestock. Nature Communications. 11-May-2016.

[5] Yellowstone Bison and Brucellosis: Persistent Mythology.  Retrieved from (3/30/19).

[6] Callenbach. 280.

[7] Yellowstone Bison and Brucellosis: Persistent Mythology.

[8] Kamath.

[9] Willcox, Louisa. 8 March 2017. The Last Stand for Yellowstone’s Bison.  Retrieved from

[10] Yellowstone Bison and Brucellosis: Persistent Mythology.

[11] Yellowstone Bison and Brucellosis: Persistent Mythology.