Legislative Audit Division, A Report to the Montana Legislature Performance Audit Brucellosis Management in the State of Montana, Dept. of Livestock, Department of Fish, Wildlife & Parks, January 2017.
Click on Legislative Audit (PDF) to download the report.
Click on Designated Surveillance Area (PDF) to download a map.
The U.S. Dept. of Agriculture Animal and Plant Health Inspection Service is paying for Montana Fish, Wildlife & Parks brucellosis management actions targeting wild elk in Montana. The taxpayer funding flows through the Montana Dept. of Livestock – from the same pot of money the livestock agency uses to destroy wild buffalo in the state.
According to Dr. Joe Templeton of Texas A& M University’s Department of Veterinary Pathobiology, in remarks made to the Greater Yellowstone Interagency Brucellosis Committee (GYIBC) on May 21, 1998:
"The so-called random shooting at the Montana borders is actually eliminating or depleting entire maternal lineages, therefore this action will cause an irreversible crippling of the gene pool. Continued removal of genetic lineages will change the genetic makeup of the herd, thus it will not represent the animal of 1910 or earlier. It would be a travesty to have people look back and say we were 'idiots' for not understanding the gene pool."
and
"Bison have developed a natural resistance, genetically, as long as they have enough to eat, limited stress, and are not consumed by other diseases. There is no magic bullet in wildlife disease, therefore management is important. Vaccines are one management tool and one component, but genetic structure is necessary for future management. Every animal which is removed from the breeding population can no longer contribute to the genetic variability of the herd."
Dr. Templeton’s statements about lineages and the gene pool of genus “Bison Bison” are directly relevant to our efforts to have threatened or endangered status of this long beleaguered species formally recognized with an Endangered Species Act listing. While he does not explicitly state the reason for his concern about “Every animal which is removed from the breeding population...”, the implication is that there are so few wild buffalo in existence that EVERY SINGLE ANIMAL is a genetic necessity if we are to ensure this species’ survival! That is why we fight so hard, and that is why we need your help. Okay, back to the science...
Population Explanation
The Yellowstone bison population currently exists as an isolated "meta-population." This is what population geneticists call a population which consists of several small groups, referred to as "subpopulations," which interact with each other to some degree. Each subpopulation within the meta-population can have its own distinctive genetic structure which distinguishes it from the others. If individuals remain in their own respective subpopulation and do not mate with outside individuals, certain genes within the subpopulation become fixed.
In other words, in isolation they lose alternative genes normally obtained through random mating and selection. This eventually leads to a loss of genetic variation in the subpopulation. If there is inter-sub-herd migration, and mating of individuals at a moderate rate between the subpopulations, then genetic variation can be maintained throughout the entire meta-population. This is most ideal, as long as the genetic exchange never includes hybridized animals.
Variety is the (Genetic) Spice of Life
Genetic variation is critical to the long-term survival and evolutionary potential for any species or population. It can become decreased through isolation, inbreeding, and strong selective pressures such as environmental changes, habitat loss, diseases, or extensive mortality.
Loss of genetic variability removes genes from the population that could enable certain individuals to survive a major event, reproduce, and pass on their genetic material to the next generation. Low genetic variability within an individual or population greatly reduces the ability to respond to a major disease event or adapt to changing environmental conditions. Ultimately, this will drive them into an extinction vortex from which they might not recover, and “beefalo” hybridization is just another huge risk factor. Genetic degradation or loss of variability has already occurred in many wild species which have disappeared from the globe.
“Must” we ever “Cull?”
The current "clear cut" style of removing bison from the Gardiner area poses a grave risk to the genetic integrity of the entire Yellowstone bison herd for a number of reasons. Perhaps the most tragic part is that the northern herd subpopulation was nearly wiped out in 1996/97.
The current herd probably consists of remnant individuals and migrants from other adjacent Yellowstone subpopulations. Removal of a large number of individuals from only one subpopulation within a single region poses the risk of permanent loss of entire lineages—a potentially irreplaceable loss to the species.
If population control were ever truly necessary (which we, for the record: doubt severely), then a scattered, random removal of individuals would probably be more conducive to maintaining genetic diversity. However, the carrying capacity for bison in the Greater Yellowstone ecosystem has not been accurately established.
“Ideal Numbers” - and How We Get There
Therefore, the current population cap of 3,000 is an arbitrary human-generated number: it is not based on science, and is not representative of what the ecosystem can actually support. If the efficiency of bison grazing patterns and their remarkable ability to extract the most nutrition from the lowest quality forage is considered in conjunction with potential availability of public lands, this number should be much higher.
Because wild buffalo naturally travel in small herds (think family subgroup), the cumulative effects of yearly removals of entire large groups of bison within an isolated population result in a steady erosion of genetic integrity within this herd. This is a national tragedy and will ultimately result in the demise of this magnificent national treasure!
We must urge our public officials to discontinue the slaughter of Yellowstone bison in this manner. We cannot allow this recurring winter nightmare to continue.
It is key to the survival of the last wild buffalo and its future generations that current removal (slaughter) operations are immediately stopped. Prevention of further herd reductions will ultimately contribute to the conservation of these small herds, and augment global biodiversity.
We will continue to offer you more science, but right now we need you to act! Will you help us protect the last wild buffalo herds?
Issue: The Montana Department of Livestock (DOL) claims it slaughters the Yellowstone bison because they carry the disease “brucellosis.” This claim rings hollow when examined in the light of objective scientific fact.
Background: Brucellosis was first detected in the Yellowstone Buffalo herd in 1917. The buffalo were exposed to brucellosis by domestic cattle that were (unwisely) allowed to graze in the park and confined with buffalo. Brucellosis is most commonly transmitted among and between species through ingestion of infected birthing materials.
Yellowstone buffalo developed a natural immune response to brucellosis and do not typically suffer from the disease. It is believed that many buffalo may also have a genetic immunity to brucellosis.
Failed pregnancies, the most common symptom of brucellosis, are relatively unknown in Yellowstone buffalo. The most likely mode of exposure among buffalo is ingestion of small amounts of bacteria from newborn live calves.
Essentially, the buffalo in Yellowstone are vaccinating themselves for brucellosis, developing an immune response, and clearing the bacteria. There isn’t a single a documented case of brucellosis transmission between buffalo and domestic cattle under natural conditions; ever! In Grand Teton National Park, where vaccinated cattle and brucellosis exposed buffalo have been commingling for decades, no transmission has ever occurred. The chances of transmission between wild buffalo and vaccinated domestic cattle have been characterized as “very low.”
Facts: A number of elements have led to the death of thousands of buffalo since 1985. The factors (which we explain in greater detail below) include the incidence and transmit-ability of brucellosis in buffalo; the distribution of cattle in the Greater Yellowstone Area; and the regulatory structure in place to reduce/eliminate brucellosis from the region.
Now we’ll explain things in even more detail, and share some additional but related information. Ready? Have you got your pocket protector in place?
Testing methods: There are currently two methods to test buffalo for brucellosis exposure and infection: serology and culture.
Transmit-ability: The most likely method of transmission between species is ingestion of infected birthing materials or from an aborted fetus. Thus bulls, calves, yearlings, and non-pregnant females do not pose a significant risk of releasing infected materials in the environment. When a female buffalo is infected with brucellosis, she will pass the bacteria in her first pregnancy. After her first calving, her uterus will “super protect” itself from brucellosis, preventing infected material from being shed in subsequent calving even if she is re-exposed. Therefore, only pregnant female buffalo in the first calving cycle after exposure have the possibility of sloughing infected material into the environment. Brucellosis related abortions, even among infected females, are extremely rare in Yellowstone buffalo. Given the very small segment of the population that can even potentially transmit brucellosis and the low probability of transmission occurring in nature, the real chances of brucellosis transmission are extremely low. Additionally, brucellosis bacteria will not survive in warm weather or direct exposure to sunlight, and the activity of predators/scavengers all but guarantee that fetuses or infected birthing material will not persist in the environment beyond mid-May.
Distribution of Cattle: Relatively few cattle graze in the Greater Yellowstone Area (GYA) at any time of the year, particularly in the winter and spring months when transmission is even a possibility. In the Western Boundary Area, no cattle are present within 45 miles of Yellowstone National Park in winter and spring. Cattle are typically only in the area between mid-June and mid-October, a period when there is no possibility of brucellosis transmission. The vast majority of cattle that graze in the summer in the Western Boundary Area are imported from Idaho and are already subjected to brucellosis vaccination and testing. In the Northern Boundary Area, there are never any cattle on the west side of the Yellowstone River between Gardiner and Yankee Jim Canyon.
One rancher grazes about 25 cows on the east side of the Yellowstone River and approximately 4 miles north of Gardiner on Rt. 89. This same producer brings his cattle to private land adjacent to the Eagle Creek Special Management Area (SMA) in the spring months. Untested buffalo are allowed to be in the Eagle Creek SMA, and no transmission of brucellosis has ever occurred. One additional producer grazes cattle on the east side of Yellowstone River north of Gardiner. Both of these ranchers have publicly stated that they welcome wild bison on their properties and are not concerned about a brucellosis transmission.
Regulatory issues: Montana is currently certified brucellosis class “Free.” Free status allows producers to transport reproductive cattle across state lines without brucellosis testing. The United States (US) is not certified brucellosis “Free” by the World Organization for Animal Health, the international regulatory body. Therefore, brucellosis testing is required to transport reproductive cattle across international boundaries. In order for the US to be certified brucellosis free, no livestock in the country can have been vaccinated for three years.
Bullying the Bulls is Bull: Many (some seasons, all) buffalo captured and slaughtered are bulls, which are incapable of transmitting the disease. Often slaughtered buffalo tested positive for brucellosis antibodies, but not the resulting infection. Because it is proven that bison build natural resistance to brucellosis, these animals (with antibodies but not infection) may actually be the strongest, healthiest animals of the herd.
The overwhelming majority of bison slaughtered according to these test results don't actually carry the disease. This means not only is DOL killing what we consider and hope to prove is an endangered species, they are killing the toughest of them...the ones that should be breeding future buffalo babies.
Antibody Detection: Most bison that test positive at a capture facility test negative under a more accurate post-slaughter necropsy. DOL uses a new testing methodology available for detecting antibodies to brucellosis in wild bison called the Fluorescent Polarization Assay (FPA). This testing method involves the use of antigens tagged with a fluorescent material which detect IgG (immunoglobulin G) type antibodies to brucellosis and bind with them. Binding between the antibody and the tagged antigen results in an increase in polarization which is detected by the analyzer and reported as a quantitative result. This result is interpreted as positive or negative based on certain value criteria. Studies have established that the specificity and sensitivity of this test were found to be much higher when compared to Particle Concentration Fluorescence Immunoassay and the CARD test.
However, in spite of the advanced technology of this testing method it is only capable of detecting IgG (long term immunity) antibodies, not the presence of brucella organisms. The major advantage of FPA over the CARD test is that it will detect a quantitative level of antibodies, which may or may not directly correlate to the presence of an infection, whereas the CARD test simply detects the qualitative presence or absence of antibodies. Although DOL has finally begun using advanced technology to detect brucellosis antibodies in wild bison, they are still unable to correlate their test results as proof of actual infection.
Recap of facts:
Simple solutions we propose:
You Can Make a Real Impact for Wild Buffalo! As you can see, there are solutions to this issue, primarily related to sharing the facts and educating the public and legislators.