The Ecologist

Yellowstone Bison. Photo: Jitze Couperus via Flickr (CC BY).
Yellowstone Bison. Photo: Jitze Couperus via Flickr (CC BY).
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  • Yellowstone land-use map via National Park Service
    Yellowstone land-use map

Bloodbath in Yellowstone: the park's plan to slaughter 1,000 wild bison

George Wuerthner

14th December 2015

Yellowstone Park is home to America's last pure-bred wild bison, writes George Wuerthner. Yet the Park's management is planning to kill around a thousand of these precious animals this winter. Ostensibly it's to protect cattle on public lands near the park from brucellosis. But bison have never been known to transmit the disease to them. The real reason is to keep all the pasture for livestock.

Everything from the killing of wolves / grizzlies, to the destruction of sage grouse habitat, to the dewatering of rivers critical to trout, and even global climate change, are a consequence of trying to raise beef for human consumption.

Recently Yellowstone National Park announced its intention to cull (read kill) as many as a thousand of the park's genetically unique and only continuously wild herd of bison.

The annual slaughter has no basis in science, and is ethically bankrupt and corrupted management precipitated by ranching interests.

The slaying of bison is an annual event. Since 1985 some 8,634 Yellowstone bison have been sacrificed to the livestock industry.

The main justification given for this carnage is the fear of brucellosis transmission to domestic livestock. The Montana Dept. of Livestock and the USDA's Animal and Plant Health Inspection Service (APHIS) have worked together to perpetrate the idea that brucellosis poses a threat to the livestock industry.

As a consequence the state and federal agencies, including the National Park Service, more or less restrict bison to Yellowstone Park although the park is surrounded by public land. There is a small area where bison are permitted outside of the park for a short period of time - but they are then almost immeciately killed by Native Americans and Montana hunters.

The 'bison wall'

Unfortunately for the bison, the urge to migrate in winter to find accessible food under shallow snow cover puts them in the cross hairs of the Montana livestock industry. A 'bison wall' (analogous to the Berlin Wall) effectively confines them to Yellowstone National Park.

The main justification given by the livestock industry for its continued support of the slaughter or hazing of wild bison is a disease known as brucellosis. There are strong reasons to believe that brucellosis is a Trojan Horse.

First, only infected pregnant bison cows can potentially transmit brucellosis during the last trimester of pregnancy (February - April). Yet bison bulls and calves are regularly slaughtered, so the killing of these animals demonstrates that brucellosis is not the primary reason for the containment of buffalo in the park.

Also keep in mind that other animals also carry brucellosis. Some elk in the Greater Yellowstone Ecosystem (GYE) are also infected with brucellosis. Predators and scavengers, such as coyotes, crows, vultures, and bears, are occasonally infected as well, though they are not at high risk for shedding the bacteria.

There has never been a single documented case of brucellosis transmission to cattle from wild bison. Indeed all the instances of cattle infection seem to be the result of transmission from elk. Despite these well-known facts, bison are still singled out for control and death.

Yellowstone bison are unique

The wild bison in Yellowstone are not just any old bison herd. They are the only completely wild bison left in the United States. They are the most significant bison herd still free of cattle genes. Wild bison are a national and international heritage asset.

Most of the bison in the US are managed as commercial livestock and any selection is for traits favorable to domestication.

Both the Buffalo Field Campaign and the Western Watersheds Project have petitioned to have Yellowstone's bison declared a threatened distinct population segment under the Endangered Species Act.

An earlier attempt to get the bison listed in 1999 resulted in the Fish and Wildlife Service's refusal to consider the listing. However, they did acknowledge that the Yellowstone population might be discreet and therefore meet the criteria for designation as a Distinct Population Segment.

To imprison the bison within Yellowstone Park, where there is not enough food  to overwinter is a national disgrace. The fact that this carnage has been going on for decades without resolution is also a scandal.

Do bison really transmit brucellosis to cattle?

The goal of eradicating brucellosis began in the 1930s. Brucellosis causes cattle to abort their first fetus and is transmissible to humans as undulant fever.  Undulant fever causes flu-like symptoms in people. The brucellosis campaign was justified by health concerns and taxpayers have spent billions on eradicating the disease.

However, the major pathway for human infection was from drinking unpasteurized milk. Once pasteurization became widespread, the human health threat was eliminated. Today's minimal number of cases arise through people drinking unpasteurized milk and/or among people who work with infected animals, like veterinarians.

That hasn't stopped the livestock industry from using the public health excuse to maintain federal funding to control brucellosis, even though it is now almost purely an economic issue for the industry - i.e. the livestock industry loses calves when brucellosis-infected cows abort them.

Today, the last major reservoir of brucellosis in the United States is found amongst wildlife in the Greater Yellowstone Ecosystem. And where did they get it from? Domestic cattle! Wild bison were infected on or before 1917 by domestic dairy cows that were once kept in Yellowstone to provide fresh milk to tourists. Apparently, brucellosis has less serious effects on wild bison than domestic cattle because the population continues to grow in spite of infection.

The extreme improbability of transmission

The risk of brucellosis transmission from bison to domestic cattle is extremely low. Testing under controlled conditions by Texas A&M researchers demonstrated that, in theory, brucellosis from bison can be transmitted to cattle (cattle were swabbed with brucellosis bacteria obtained from an infected bison).

However, there has never been a documented case of brucellosis transmission from wild bison to domestic livestock. There are a number of reasons for this:

  • Firstly, only pregnant female bison can abort a fetus and this does not happen very often. Most wild bison pose no risk - bulls, calves, non-pregnant cows and cows with calves cannot transmit brucellosis to cattle. If infected with brucellosis, the bison cow appears to reabsorb the fetus. This makes sense from an evolutionary perspective because the risks and costs of calving are significant, and if the bison's body is able to confirm the calf is infected, it makes sense to terminate the birth.
  • Secondly, an aborted bison calf would have to remain available for a domestic animal to find it and lick it. Given the abundance of natural scavengers including coyotes, ravens, magpies, and eagles found in the region, the chances that any infected bison fetus would remain on the ground more than a few days is extremely small.  Added to which, the brucellosis bacteria is extremely sensitive to heat, drying out and so forth, and only remains viable outside of the body for short periods of time.
  • Thirdly, the main time period for reabsorption and/or abortion of the fetus is in late winter (Feb-April). The chances this would occur on pastures in the Yellowstone area actively being grazed by domestic livestock is extremely small. All public grazing allotments are devoid of cattle at this time, and even many of the private grazing lands are only stocked with cattle in the summer months.

As the main way a domestic animal can contract the disease is by licking a brucellosis-infected aborted bison fetus, the fact that the opportunity for this occurs so rarely massively limits the opportunity for transmission.

A simple ruse to prevent competition for pasture?

Other factors that also cut the chances of infection are vaccination / inoculation of cattle. A vaccine that protects cattle against infection exists, but it is not required in Montana except in the immediate area surrounding Yellowstone. While not considered 100% effective, the vaccine does significantly reduce the chance for brucellosis infection in domestic animals.

Finally, even if an infected animal shows up in a rancher's herd, it is not a total loss. The herd is quarantined while it is tested for the disease. Animals testing positive for brucellosis are removed (sold for meat), and the remainder of the herd can be  maintained.

In summary, the probability of transmission of brucellosis from bison to domestic livestock is extremely low. To do so would require all of the following to occur:

  • An infected bison cow must abort her fetus, something that apparently is very rare in wild bison.
  • The bacteria must remain alive and the aborted fetus has to be missed by scavengers anxious to consume an easy meal.
  • The aborted bison fetus has to occur where there is active grazing by domestic livestock - something rare in the colder regions where bison graze in winter months.
  • Finally, a domestic animal has to find the infected fetus, lick it, consume an infective dose and be a domestic animal that was not effectively vaccinated in an area where most are.

As any statistical analysis would tell you, the chance of all these variables being met are almost zero. The threat of bison transmission to cattle is just a ruse to justify control of wild bison by the livestock industry who fear foraging competition from wild bison on public and private lands.

The bison herd has 'grown too large' - too large for what?

Because the brucellosis transmission scam is increasingly being questioned by scientists, and others, the latest excuse for killing bison is to 'reduce' the population. You will hear people saying they are no longer shooting bison to prevent brucellosis transmission, but to 'cull' the herd which has 'grown too large.'

However, the only reason the herd is 'too large' is that it's bottled up in the park. The majority of animal wildlife's winter range is located outside of the park borders but this is unavailable to the bison because of the senseless demands of the livestock industry. If the vast amount of public land (and bison-friendly private lands) outside of the park (see map, above right) were available to bison, there would be no need for 'culling' by any government agency.

Currently some bison that attempt to migrate from the park are killed by Indians and/or Montana-licensed hunters in small confined zones close to the Park. All of this killing provides cover for the livestock industry.

In addition, bison captured and slaughtered by the Department of Livestock or the National Park Service are given to loca Indian tribes, which also provides an easy way to put a happy face on what is in effect a totally unnecessary slaughter of unique and rare animals.

In essence, tribal members and Montana hunters are doing the  livestock industry's dirty work.

Room to roam

At present there are almost no cattle that winter in the regions north and west of Yellowstone where bison migrate during harsh winters seeking food. Most of the public lands grazing allotments near West Yellowstone, as well as north of Gardiner, have been closed. Furthermore, many of the private land owners in both places actually support having wild bison on their properties.

In recent years seasonal 'bison tolerance zones' have been established in the Gardiner Basin / Eagle Creek areas adjacent to Gardiner, and in the West Yellowstone area.  However, there is absolutely no reason we need 'tolerance' zones in the first place.

Bison should be permitted to roam on public lands year-round just like all other wildlife. There is no legitimate justification for the selective killing of bison. The brucellosis threat is nothing more than a subterfuge designed to garner control over our wildlife by livestock interests.

Keep in mind that we do not automatically shoot wolves that leave Yellowstone. We do not automatically shoot grizzlies that leave Yellowstone. We don't automatically shoot pronghorn, mule deer, or elk that leave Yellowstone.

Elk are among the major vectors for brucellosis transmission. Indeed, all 20 reported cases of brucellosis in GYE cattle were the result of elk transmission. Elk concentrate on feeding grounds, as occurs in Wyoming, and are thus at a higher risk of contracting the disease from other infected elk. Estimates suggest that 35% of the elk on  the Wyoming feedgrounds are infected.

Thus one solution is to phase out and eventually close the feedgrounds in Wyoming to prevent disease transmission of brucellosis, as well as other threats to wildlife and livestock like Chronic Wasting Disease (better known as Mad Cow Disease). This would reduce the livestock industry's ability to continue with its brucellosis deception.

Protection in law - and open up public lands to bison!

In addition to the above, the biggest factor that could change the game is if bison were listed under the ESA. If they were given the protection they deserve, the Department Of Labor would not be able to be so cavalier about killing these animals. Indeed, it would force the federal agencies like the Forest Service to work towards restoration of bison on federal lands. (Please send donations to the Buffalo Field Campaign and Western Watersheds to help in this effort).

Yellowstone is surrounded by public lands. Currently all of Montana's nearby state wildlife management areas, including Dome Mountain, Gallatin, Bear Creek and Wall Creek are unavailable to the bison. Also most of the Custer-Gallatin NF and all of the B-DNF and the Caribou-Targhee NF are off limits to bison. This needs to be changed. There is no justification for prohibiting wild bison from occupying public lands surrounding Yellowstone.

We should open up adjacent federal lands in the Custer-Gallatin, Bridger-Teton and Caribou-Targhee National Forests, and nearby state wildlife lands like Dome Mountain Wildlife Management Area. In additon, listing under the ESA could speed reintroduction to other suitable federal lands like the Red Rock Lakes National Wildlife Refuge; the Charles M. Russell Wildlife Refuge in Montana; on Bureau of Land Management lands in Wyoming's Red Desert; and Idaho's Craters of the Moon National Monument.

There are National Park Service (NPS) employees who are strongly opposed to the annual capture and carnage of wild bison. Secretary of Interior Jewell could direct Yellowstone National Park to drop its cooperation in the bison slaughter and conserve bison under its natural regulation policy asit does for all other wildlife species.

Biodiversity and wildnerness sacrificed to livestock

While this might not end the butchery occurring beyond the park borders, at the very least it would make the public aware of who is behind this slaughter - namely the livestock industry.

At present, due to the participation of the Park Service, tribes, and even Montana hunters, the livestock industry is getting a pass in the public relations department. Most people assume that if the NPS is participating, than killing bison must be OK.

Keep in mind that livestock production harms many other species besides bison. Everything from the killing of wolves / grizzlies, to the destruction of sage grouse habitat, to the dewatering of rivers critical to trout, and even global climate change, are a consequence of trying to raise beef for human consumption. 

One of the easiest ways you can undermine the ranching industry is to eat less beef, and get friends and neighbors to understand that when they consume a hamburger, they are helping to kill wild bison, wolves, and other wildlife.



George Wuerthner has published 36 books including Wildfire: A Century of Failed Forest Policy.

This article was originally published on CounterPunch.


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