Bison and Wolves: Is Culling Once-Threatened Species Justified?

Candice Gaukel Andrews September 30, 2014 15

This winter, almost a fifth of our nation’s pure-bred bison herd in Yellowstone National Park will be culled. ©Henry H. Holdsworth

As many as 900 Yellowstone National Park American bison may be exterminated in winter 2014-2015. It’s estimated that our nation’s last, pure herd of free-ranging bison that have managed to continuously live on their native grounds currently numbers at 4,900. That means that a fifth of this near-threatened species is soon to be killed.

On the state level, I see a similar prospect for this winter regarding gray wolves. In Wisconsin, where I live, the natural resources board has recently approved a wolf quota of 156 animals for the 2014 hunting season. It’s part of Wisconsin’s wolf management plan, which calls for reducing the state’s wolf population by about 45 percent, from approximately 800 wolves to 350 in a three-year span.

Less than only three years ago, on January 27, 2012, the gray wolf was removed from the federal endangered species list in the Western Great Lakes area following a decades-long federal government effort to repopulate the animals after they were nearly wiped out in the early 20th century.

When once-threatened species have only recently recovered enough to be delisted, should we be so quick to institute culling measures?

Wisconsin’s 800 wolves will be cut back to 350 in three years. ©Henry H. Holdsworth

Worries about land and livestock

Once, 30 million Bison bison roamed the plains west of the Mississippi River. But systematic hunting after European settlement drove their numbers down to fewer than 50. Those remaining animals found refuge in Yellowstone in the early 1900s. Today, the population has recovered to almost 5,000, a number that is above the 3,000 to 3,500 goal set in a management plan hammered out among federal and state agricultural and wildlife agencies.

Agreeing to keep bison numbers that low is in part a response to fears among ranchers in Idaho, Montana and Wyoming that bison migrating each winter from Yellowstone to historic grazing grounds could spread the bacterial disease brucellosis to livestock. Roughly half of Yellowstone’s bison have been exposed to the disease, most likely brought to the park by cattle that once grazed there. Brucellosis, which can cause cows to miscarry, has been virtually eradicated from Montana livestock; and the state’s brucellosis-free status allows ranchers to sell and ship cattle across state lines without expensive quarantines, tests and vaccinations.

According to the National Park Service, bison are also prolific when environmental conditions are favorable and have high survival rates, soon filling what available habitat there is for them and out-pacing the acquisition of additional habitat. While the carrying capacity of the land inside the park could be as high as 5,500 to 7,500 bison during winter, lower-elevation habitat for bison is limited by mountains in the park and by competition with agriculture, development and transportation systems outside the park’s boundaries.

In Wisconsin, a similar reasoning is used to support wolf culling. Gray wolves, which have lived in the state since the glaciers retreated 10,000 years ago, were driven to extinction here in 1960 after a century of elimination efforts. They began to make a comeback along the Minnesota border in 1975. In 1989, the Wisconsin Department of Natural Resources launched a plan to recover the species. Wolves were reclassified on the state level from “threatened” to “protected wild animal” in 2004 when the population passed 350.

Proponents of reducing the population back down to 350 say that 800 wolves is far too many for the habitat the state currently has for them and that drastically reducing their numbers would decrease wolf depredations on livestock, deer, hunting hounds and, occasionally, pets.

Pressure from special interest groups

The number of bison culled from Yellowstone National Park has varied widely from year to year, but the 900 slated for this winter represents the largest slaughter in seven years.

Yellowstone’s elk—which also carry brucellosis—are not culled. ©Henry H. Holdsworth

Those who oppose the culling have argued that no other wildlife in the national park, including elk—which also carry brucellosis—is killed while following an ancient winter migration route (although wolves choose elk over bison). A state veterinarian in Montana, Marty Zaluski, has suggested a plan to shoot bison with “biobullets,” absorbable projectiles containing a vaccine against brucellosis. Yellowstone managers, however, rejected that plan because of its cost of $9 million and questions about its ultimate effectiveness.

According to sustained yield theory (the ecological yield that can be extracted without reducing the base of the capital itself)—a prominent approach for managing wildlife—a species’ population numbers should be at no less than half of its habitat’s total carrying capacity to ensure long-term stability. Above that level, a population can naturally rebound from environmental variations and harvest seasons. Experts have estimated that the carrying capacity for wolves in Wisconsin is 900. But at 350, small mistakes in management would no longer be self-correcting and could lead to instability.

Surprisingly, the Wisconsin Wolf Advisory Committee does not allow members who are University of Wisconsin biologists, UW faculty or representatives from wolf advocacy groups. The recently revamped committee now has more representation from members who belong to special interest groups, including sportsmen from hunting and trapping organizations and hunting hound enthusiasts.

This year’s planned large cull of bison comes at the same time that there is a call to declare Bison bison as our national mammal. Unlike the grizzly bear that appears on the California state flag, I hope that once designated as such, there will be enough real bison left in our nation for future generations to see in the flesh.

Do you think culling recently threatened or near-threatened species can be done without placing such animals in serious danger of extinction, or should longer periods of recovery and a higher population minimum be mandated before any population reduction measures are taken?

Here’s to finding your true places and natural habitats,



  1. Brian Bastarache October 9, 2014 at 8:41 am - Reply

    How many large tracts of habitat still exist? Tracts large enough to support sustainable populations of migratory megaherbivores and of their associated apex predators are very few in the North America. Try this: Open Google Earth and zoom in on any part of the central US – the places were prairies once were. Do it multiple times. You won’t find much habitat for wildlife, much less large wildlife.

    Each bison needs many acres of range to meet its needs. Wolves need an order of magnitude more than the herbivores on which they prey.

    Scientifically managed hunts can raise money and increase tourism. The increased tourism gives value to the community (to those who can only understand the value of money – which is most people it seems) and the funds raised from the sale of permits may be used to purchase habitat and other conservation work.

    The Wildlands Stamp program has raised millions of dollars in Massachusetts with which the MA Division of Fisheries and Wildlife has purchased and protected thousands of acres for wildlife. If that can be done in a small state where land costs hundreds of thousands of dollars per acre; imagine what can be done in Wyoming.

  2. Tandin Tobden October 7, 2014 at 10:03 am - Reply


  3. Paul Pendlebury October 6, 2014 at 3:41 pm - Reply

    How about moving some of them to the areas where they were found before thus extending their range and hopefully the species?

  4. Leland Brun October 5, 2014 at 4:08 pm - Reply

    “Wildlife Management” as often practiced, means providing more fish and game for sportsmen or providing the justification for limiting wildlife populations to fit into ever more diminished habitats. This was typical of wildlife management in the ’60s and ’70s when I was working in state conservation. Most of the people employed were sportsmen and motivated by those interests. I even heard some religious statements regarding “God gave us dominion over fish and wildlife” to manage for our benefit. This from a state wildlife manager. Lately, I have seen some glimmers of new understanding regarding our place in nature.

  5. Anna Pole October 5, 2014 at 4:06 pm - Reply

    It does seem to be counteracting the many years of conservation work that increased the numbers of these populations in the first place. And it’s difficult to estimate exactly how many animals can be culled sustainably.

  6. Thomas Nesler October 5, 2014 at 12:58 pm - Reply

    I would say “yes” on the bison in YNP; and while I do not or would not hunt wolves as a matter of personal desire, I think some hunting and harvest of wolves is okay. I think the removal of up to 45% of the wolf population in Wisc is radical and would like to see the data that justifies such an extreme measure. If you have met and exceeded the recovery goals for a formerly declining species, then allowing hunting is not unwise. If hunting is not conducted in a manner sensitive to the abundance of the recovered population, then it is unwise. Putting these separate topics under one thread is mixing apples and oranges and will only disrupt an effective conversation.

  7. Bob Mahoney October 2, 2014 at 7:23 pm - Reply

    I’ve been remotely involved with this subject since the 1970’s. The cattlemen inMT, hold a big lobby and a loud voice. The tribes and conservation organizations all want to repopulate any large amounts of unowned ground with bison. These animals when and if they clear quarninteen are still not wanted because of fear.
    Fear of bruecellosis even when the bison clear quarninteen, this is about grass and a cheap way to raise their cattle. Cattle ranchers fear they will loose their cheap grazing leases on Govt./public land, But whoo be tide if you want to rent or lease the same type and amt. of ground from them it will cost you more for eaach AUM even at today’s prices about $1.35 to 16.80 per AUM
    Thank you

  8. Brian Bastarache October 2, 2014 at 10:10 am - Reply

    Use Google Earth to “look” around the area around Yellowstone and other parts of North America that was once prairie. The entire middle of this continent has been converted to a patchwork of square and center pivot (circular) agricultural monocultures. There is not habitat left. A more productive question is: How can money be raised to begin buying back land to restore our American grasslands?

  9. Kunda Wicce October 1, 2014 at 6:43 pm - Reply

    Thank you for bringing up this topic for discussion. I would like to see the “culled” animals kept in family groups and moved to the various indigenous population reservations if welcomed there.

  10. Leland Brun October 1, 2014 at 6:42 pm - Reply

    I studied “Wildlife Management” in college back in the “60s. I have worked in environmental capacities in several jobs but have never really wanted to act as a wildlife manager. My take on it if you need to actively manage wildlife, it is no longer wildlife. You are then working as a farmer of animals for human desires. Given sufficient space and lack of environmental damage from mankind, wildlife can take care of itself, thank you very much. Ideally, 75% of all world biomes should be without human development or management. Human controlled areas should exist in a matrix of interconnected wild space instead of the other way around. I see this as the only logical way to ensure planetary survival and the continuation of natural evolution.

  11. Nancy Golden-Burton October 1, 2014 at 6:41 pm - Reply

    It sounds more like what is best to relieve the fears of financial loss of ranchers is what is being done than concern for the carrying capacity of the land regarding Bison bison. Similar story with the wolves. Is there any way to stop it?

  12. Thomas Sawyer October 1, 2014 at 6:39 pm - Reply

    One interesting perspective comes from the Bible:
    “Let us make mankind in our image, in our likeness, so that they may rule over the fish in the sea and the birds in the sky, over the livestock and all the wild animals, and over all the creatures that move along the ground.” (Genesis 1:26).

    However, the reasons must still be totally justified for the culling of any kind, of any species-morally, legally (the Endangered Species Act), fairly, ethically, and in an unbiased and logical manner (such as eliminating the spread of diseased animals), but by no means should such acts be performed recklessly, selfishly, or foolishly. Is this being done? Who’s to say, but just like so many eco-tragedies, perhaps man’s pleasure takes precedence over the continued existence and sustainable natural world-that in itself in my opinion, is the biggest tragedy of all.

  13. Jim Backus October 1, 2014 at 3:01 pm - Reply

    No matter what you color it ,it’s still hunting. Remember what is going on in Minnesota, Idaho, Montana and Wyoming. If we keep this up the wolf will be back on the endangered list.

  14. Sinnadurai Sripadmanaban October 1, 2014 at 5:55 am - Reply

    As man has encroached into the habitats of animals,birds & reptiles, they don’t have sufficient food. Under these circumstances selective culling may be considered.

  15. Phillip Tureck - FRGS September 30, 2014 at 10:00 am - Reply

    Today was turning out to be a good news day until I read an article about Wolves in Wyoming and now Yellowstone and Wisconsin. I am sure that in some instances there is a need to ensure that for the ever decreasing natural habitat you have to look at managing a species but the figures of how many bison roamed the country is 900 a realistic number in a small population. Wolves is a much more evocative subject – save as many as we can please.

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