Conservation of American bison

Bison once roamed across most of North America in numbers that reached into the tens of millions. Such abundance made the bison a critical part of Native American culture: providing food as well as materials for clothing, shelter, tools, and more. As European Americans settled in the west in the 1800s, bison became the staple food for early explorers, fur traders, and many European settlers. As conflict with settlers developed, the U.S. Army began a campaign to remove Native American tribes from the landscape by taking away their main food source.[2]^: 2 Hundreds of thousands of bison were killed by U.S. troops and market hunters.[3] The rapid slaughter of bison also surged when a tanning method was developed that allowed the soft hide to be made into tougher, more desirable leather. The transcontinental railroad was key in facilitating the large-scale hunting of bison along with the development of the repeating rifle.[4] By the late 1880s, the great herds of bison that once dominated the landscape were nearly gone. Various efforts to preserve the species through protection and stewardship began. Impediments to the recovery effort would include cattle gene introgression, the potential spread of brucellosis, the nomadic behavior of wild herds, and legal jurisdiction.[5]

Some animals found protection on private ranches.[3] In 1874, Samuel Walking Coyote, a Native American man, captured a few wild bison and brought them 250 miles (400 km) to graze in a pasture near St. Ignatius, Montana.[6] The small group of animals on Blackfeet land were later sold to horse traders Charles Allard and Michel Pablo. By the early 1900s, the Pablo-Allard herd was said to be the largest collection of the bison remaining in the U.S and were threatened by the loss of grazing rights.[7] The United States government rejected a sale offer so the Canadian government purchased 410 of the bison in 1907.[8]^: 23 The bison were shipped by train from Ravalli, Montana, to Elk Island to establish a conservation herd.[6]

Yellowstone National Park was established on March 1, 1872[9] where bison had dwindled to about two dozen that spent winter in Pelican Valley. Yellowstone’s managers set about recovering the bison population. In May 1894, Congress enacted a law making buffalo hunting in Yellowstone National Park illegal. In 1902, they purchased 21 bison from private owners and raised them in Mammoth and then at the Lamar Buffalo Ranch.[3]

The bison at Lamar Buffalo Ranch eventually began to mix with the free-roaming population in Yellowstone Park and by 1954, their numbers had grown to roughly 1,300 animals. Bison reproduce and survive at relatively high rates compared to many other large, wild mammals, so even as the population recovered managers limited its growth with frequent culling. A moratorium on culling, that began in 1969, resulted in the bison population increasing dramatically.[3] Removals began again in 1991 and averaged 233 bison per year from 1991 through 2017 as wildlife officials tried to curb some of that rapid growth of 10 to 17 percent every year. Yearly guidelines were issued on how many bison should be removed.[10] Many slaughtered bison were provided to Native American Indian tribes, relief agencies and contract sales. Some live bison were shipped to zoos, reservations and other parks.[11]

During the latter half of the 20th century, park management philosophies shifted away from husbandry practices to restoring wild behaviors and allowing bison to move freely within Yellowstone National Park.[11] Establishing bison herds with heritage genetics and minimal cattle introgression became a widespread, collaborative effort.[12] Ecocultural bison conservation concurrently pursued species conservation, restoration of ecological processes, and support of the traditional human use of natural resources.[13] An ecocultural approach addresses the unique historical connection between bison and indigenous peoples, and the iconic status of bison for Canada and the United States. Many tribes and First Nations seek to establish and manage their own bison herds, to rescue and sustain cultural practices and sacred rituals, promote food security, and nourish cultural identity.[13] The restoration of ecological processes emphasizes their impact upon the ecosystem beyond the importance of the bison at the level of an individual species.[8]^: 4 The grazing of bison is important to soil, vegetation and overall ecological balance.[14] Prairie ecosystems were maintained by a pattern of disturbance caused by natural wildfire and grazing by bison, a pattern which is called pyric herbivory. Before the 1800s, bison were a keystone species for the native shortgrass prairie habitat as their grazing pressure altered the food web and landscapes in ways that improve biodiversity.[15] The full potential of bison can best be achieved in large herds on extensive landscapes where natural limiting factors are present with minimal human interaction.[2]^: 2

The US Department of the Interior (DOI) is the principal conservation agency of the United States and is responsible for the majority of the nationally owned public lands as well as its natural and cultural resources The DOI manages approximately one third of North America’s wild bison. The National Park Service (NPS), US Fish and Wildlife Service (USFWS), and Bureau of Land Management (BLM) lands support appropriately 11,000 bison in 19 herds across 12 states. Together with the Bureau of Indian Affairs and the US Geological Survey, these DOI agencies promote bison conservation and shared stewardship.[1] The 2008 issuance of the Bison Conservation Initiative (BCI) chartered the DOI Bison Working Groupon (BWG), an interagency group comprising representatives of the National Park Service, U.S. Fish and Wildlife Service, Bureau of Land Management, Bureau of Indian Affairs, and the U.S. Geological Survey.[13] The Bison Conservation Initiative (BCI) was updated and adopted in May of 2020.[1] BWG, in conserving bison as wildlife, manages bison around principles and practices that maintain the wild character of bison, minimizes artificial selection, and allows forces of natural selection to operate, including competition for breeding.[16] Using a metapopulation management strategy maintains genetic diversity and integrity through an interagency, science-based approach to restore gene flow across DOI bison conservation herds.[17] The DOI works with conservation partners, states, tribes, nations, and non-governmental organizations (NGOs), to maintain large, wide-ranging, multi-jurisdictional bison herds on appropriate large landscapes.[13]

Bison herds grow at a rate that rapidly outpaces the available habitat on DOI bison management units. Capture is periodically required to manage herd size and provides opportunities to donate live bison in support of partner conservation and restoration efforts. Low-stress handling practices reduce animal stress and increase safety for both bison and personnel during capture operations, while increasing overall alignment with the goal to manage bison as wildlife. BWG manages diseases in bison that may affect domestic livestock or other bison herds.[13]

Three free-ranging herds are managed by the National Park Service in the Grand Canyon, Grand Tetons, and Yellowstone national parks.[5] Yellowstone National Park is the only place in the United States where bison have lived continuously since prehistoric times.[18] The Grand Tetons and Yellowstone herds are considered genetically pure without signs of cattle gene introgression but are not disease-free. The Grand Canyon herd is disease free but not genetically pure.[5]

Wind Cave National Park introduced 20 bison in 1913–16; Theodore Roosevelt National Park introduced 29 animals to a South Unit in 1956 and subsequently transferred 20 bison from that herd to the park's North Unit in 1962; and Badlands National Park introduced 53 animals in 1963–64 and another 20 in 1984. The four herds are confined within fences, and no known introduction of new bison into the gene pools has occurred. The four herds are routinely culled down to approximately 425, 350, 200, and 700 animals, respectively. These smaller and spatially-constrained herds are being managed to restore ecological processes.[13]

Only a few bull bison traversed outside Yellowstone National Park prior to 1975, but as bison numbers increased, groups of bison began migrating across the north and west boundaries of Yellowstone to expand their winter range and pioneer new territory. Park and state wildlife officials went to great lengths to prevent bison from mixing with cattle.[3] Brucellosis is known to exist in the elk and bison of the Yellowstone ecosystem.[19] State and federal officials were pressured to prevent the spread of the disease as ranchers worry it could lead to Montana losing its brucellosis-free status.[20] State and federal officials rounded up most bison that wander outside the park every winter with up to 900 being removed annually.[21] Some were captured and shipped to slaughter while others were shot by hunters or state agents.[3] Montana managed a state-licensed hunt for bison that left the park from 1985 to 1991 but the number of bison migrating outside of the park continued to increase, prompting the National Park Service to develop management plans to control bison near the park boundaries. Intense controversy grew between environmentalists, livestock interests and agency managers.[11] Montana state law does not allow the transport of wild bison exposed to brucellosis except to meat processing and research facilities within the state.[22] In 1995, the state of Montana sued the National Park Service for allowing bison to leave the park. After five years of litigation and mediation, the state of Montana and the federal government developed the Interagency Bison Management Plan (IBMP) to guide the management of bison in and around Yellowstone. As part of this plan, five agencies and three tribal entities work to sustain a wild, wide-ranging bison population and reduce the risk of brucellosis transmission from bison to cattle.[3]

In the decades since the IBMP was created, the bison population has ranged between 2,400 and 5,500 animals. There have been no cases of bison transmitting brucellosis directly to cattle, in part due to efforts by federal and state agencies to maintain separation between these animals. The state of Montana now allows bison to occupy some habitat adjacent to the park that was previously off-limits, including year-round in some areas, which is a major conservation advancement. The lack of tolerance for wild bison in most areas outside Yellowstone continues to limit restoration. Large parts of their historic winter ranges are no longer available due to human development and states only allow limited numbers of bison in areas near the park.[3]

Yellowstone bison are exceptional because they comprise the nation’s largest bison population on public land.[18] Developing a quarantine program that complied with Montana state law was critical to getting brucellosis-free animals from Yellowstone to conservation herds.[22] Two pens in a Yellowstone bison trap near Gardiner were made into quarantine corrals with two layers of fencing in 2017.[20] The Bison Conservation Transfer Program allowed some captured bison that repeatedly test negative for brucellosis to provide disease-free bison with Yellowstone heritage genetics to tribes and First Nations.[3] In addition to supporting cultural restoration, the quarantine program can support genetic conservation of DOI herds by incorporating Yellowstone-origin bison into the DOI metapopulation.[13] Quarantine has three phases. First, bison are trapped and tested for brucellosis. Bison that test negative can go into quarantine. Next, testing protocols continue until the animals can be certified as disease free. Finally, assurance testing involves another year in isolation with two more tests before the quarantine period is finished. Quarantine was talked about in the 1990s during the negotiations on the IBMP.[20] During 2005-2012, Animal and Plant Health Inspection Service (APHIS) developed and verified procedures for identifying Yellowstone bison that don't have brucellosis.[23] Quarantine worked as bison that repeatedly tested negative for the disease stayed that way.[20] The first two phases currently must be done in a supervised area in the vicinity of the park. The final phase can be performed at the Fort Peck Indian Reservation in northeastern Montana.[22]

The InterTribal Buffalo Council, as an advocates for tribal buffalo restoration, supported the construction of the quarantine facility at the Fort Peck Indian Reservation. They facilitate the transfer to tribes and First Nations who will use the bison to increase the genetic diversity and overall health of their own herds.[24]

The first transfer into phase three to the Assiniboine and Sioux Tribes of the Fort Peck Indian Reservation under the new operational quarantine program occurred in August 2019.[25] Since 2019, 154 bison have been transferred to the Fort Peck Tribes in northeastern Montana. Of those, 82 were transferred to 17 other tribes across the country. Another 110 animals are in the program will be transferred to the Fort Peck Tribes in the coming years.[3]

Three free-ranging herds are managed by state wildlife agencies in Utah and Alaska.[5]

•  This article incorporates public domain material from websites or documents of the National Park Service.