Meat industry

In America, the commercial industry for bison has been slow to develop despite individuals, such as Ted Turner, who have long marketed bison meat. In the 1990s, Turner found limited success with restaurants for high-quality cuts of meat, which include bison steaks and tenderloin.^[52] Lower-quality cuts suitable for hamburger and hot dogs have been described as "almost nonexistent".^[52] This created a marketing problem for commercial farming because the majority of usable meat, about 400 pounds for each bison, is suitable for these products.^[52] In 2003, the United States Department of Agriculture purchased $10 million worth of frozen overstock to save the industry, which would later recover through better use of consumer marketing.^[53] Restaurants have played a role in popularizing bison meat, like Ted's Montana Grill, which added bison to their menus. Ruby Tuesday first offered bison on their menus in 2005.^[53] According to USDA's Agricultural Research Service, 100 g of raw bison (separable lean only) contains 109 calories and 1.8 g fat. The same amount of raw beef (separable lean only, choice grade) contains 291 calories, and 24 g fat.^[54]
In Canada, commercial bison farming began in the mid 1980s, concerning an unknown number of animals then.^[55] The first census of the bison occurred in 1996, which recorded 45,235 bison on 745 farms, and grew to 195,728 bison on 1,898 farms for the 2006 census.^[55]
Several pet food companies use bison as a red meat alternative in dog foods. The companies producing these formulas include Natural Balance Pet Foods, Freshpet, The Blue Buffalo Company, Solid Gold, Canidae, and Taste of the Wild.

Human impact

See also: Bison hunting

Photo from the 1870s of a pile of American bison skulls waiting to be ground for fertilizer.

Humans were almost exclusively accountable for the near-extinction of the American bison in the 1800s. At the beginning of the century, tens of millions of bison roamed North America. Humans slaughtered an estimated 50 million bison,^[47] not for sustenance, but for sport, supported by the military as an act of war on behalf of the U.S. Federal Government to restrict the dominant American Indian food supply.^[48] The overhunting of the bison reduced their population to hundreds. Attempts to revive the American bison have been highly successful. Farming of bison has increased their population to nearly 150,000. The American bison is, therefore, no longer considered an endangered species.^[49] The extinction of four species of bison (B. antiquus, B. latifrons, B. occidentalis, and B. priscus) was due to natural selection (see section Evolution and genetic history).
As of July 2015, an estimated 4,900 bison lived in Yellowstone National Park, the largest U.S. bison population on public land.^[50] During 1983–1985 visitors experienced 33 bison-related injuries (range = 10–13/year), so the park implemented education campaigns. After years of success, five injuries associated with bison encounters occurred in 2015, because visitors did not maintain the required distance of 75 ft (23 m) from bison while hiking or taking pictures.^[51]

Infections and illness

For the American bison, the main cause of illness is malignant catarrhal fever,^[43] though brucellosis is a serious concern in the Yellowstone Park bison herd. Bison in the Antelope Island bison herd are regularly inoculated against brucellosis, parasites, Clostridium infection, infectious bovine rhinotracheitis, and bovine vibriosis.^[44]
The major concerns for illness in European bison are foot-and-mouth disease and balanoposthitis, which affects the male sex organs; a number of parasitic diseases have also been cited as threats.^[45] The inbreeding of the species caused by the small population plays a role in a number of genetic defects and immunity to diseases, which in turn poses greater risks to the population.^[45]

Name

The term "buffalo" is sometimes considered to be a misnomer for this animal, as it is only distantly related to either of the two "true buffalo", the Asian water buffalo and the African buffalo. However, "bison" is a Greek word meaning ox-like animal, while "buffalo" originated with the French fur trappers who called these massive beasts bœufs, meaning ox or bullock—so both names, "bison" and "buffalo", have a similar meaning. Though "bison" might be considered more scientifically correct, as a result of standard usage, "buffalo" is also considered correct and is listed in many dictionaries as an acceptable name for American buffalo or bison. In reference to this animal, the term "buffalo" dates to 1635 in North American usage when the term was first recorded for the American mammal. It thus has a much longer history than "bison", which was first recorded in 1774.^[46]

Diet

This section needs expansion. You can help by adding to it. (May 2012)

Bison are herbivores and eat simple foods.They generally rest during day and graze in the mornings and the evenings. The bison's main foodstuff is grass and sedges,^[39] though they will also eat any available low-lying shrubbery.^{[citation needed]} In the winter, bison forage for grass under the snow. If little grass is available, they will eat the twigs of shrubs. Bison are notably better browsers than cattle, since cattle are more obligate grazers, though wood bison have also been described as "obligate grazers".^[40] Wisent tend to browse on shrubs and low-hanging trees more often than do the American bison, which prefer grass to shrubbery and trees.^[41]

Predators

Wolves hunting bison

This section needs expansion. You can help by adding to it. (May 2012)

Due to their size, bison have few predators. Five notable exceptions are the grey wolf, human, brown bear, coyote, and grizzly bear.^[42] The grey wolf generally takes down a bison while in a pack, but cases of a single wolf killing bison have been reported.^[35] Brown bear also prey on bison calves, often by driving off the pack and consuming the wolves' kill.^[4] Historically and prehistorically, lions, tigers, Smilodon, and cave hyenas had posed threats to bison.

Habitat

American bison live in river valleys, and on prairies and plains. Typical habitat is open or semiopen grasslands, as well as sagebrush, semiarid lands, and scrublands. Some lightly wooded areas are also known historically to have supported bison. They also graze in hilly or mountainous areas where the slopes are not steep. Though not particularly known as high-altitude animals, bison in the Yellowstone Park bison herd are frequently found at elevations above 8,000 feet and the Henry Mountains bison herd is found on the plains around the Henry Mountains, Utah, as well as in mountain valleys of the Henry Mountains to an altitude of 10,000 feet.
European bison tend to live in lightly wooded to fully wooded areas and areas with increased shrubs and bushes, though they can also live on grasslands and plains.

Restrictions

Throughout most of their historical range, free-ranging bison are not tolerated by landowners or state governments. Herds on private land must be fenced in.^[36] In the U.S. state of Montana, free-ranging bison on public land may be shot, citing concerns of spreading disease and damage to public property.^[37] Legislation surrounding the bison continues to be proposed and vetoed by the governor of Montana, and remains an issue of contention between Native American tribes and the American government.^[38]

Behavior

Wallowing is a common behavior of bison. A bison wallow is a shallow depression in the soil, either wet or dry. Bison roll in these depressions, covering themselves with mud or dust. Possible explanations suggested for wallowing behavior include grooming behavior associated with moulting, male-male interaction (typically rutting behavior), social behavior for group cohesion, play behavior, relief from skin irritation due to biting insects, reduction of ectoparasite load (ticks and lice), and thermoregulation.^[32] In the process of wallowing, bison may become infected by the fatal disease anthrax, which may occur naturally in the soil.^[33]
Bison temperament is often unpredictable. They usually appear peaceful, unconcerned, even lazy, yet they may attack anything, often without warning or apparent reason. They can move at speeds up to 35 mph (56 km/h) and cover long distances at a lumbering gallop.^[34]
Their most obvious weapons are the horns borne by both males and females, but their massive heads can be used as battering rams, effectively using the momentum produced by what is a typical weight of 2,000 pounds (900 kg) (can be up to 2700 lbs) moving at 30 mph (50 km/h). The hind legs can also be used to kill or maim with devastating effect. In the words of early naturalists, they were dangerous, savage animals that feared no other animal and in prime condition could best any foe^[34] (except for wolves and brown bears^[4][35]).
The rutting, or mating, season lasts from June through September, with peak activity in July and August. At this time, the older bulls rejoin the herd, and fights often take place between bulls. The herd exhibits much restlessness during breeding season. The animals are belligerent, unpredictable, and most dangerous.^[34]

Evolution and genetic history

The bovine tribe (Bovini) split about 5 to 10 million years ago into the buffalos (Bubalus and Syncerus) and a group leading to bison and taurine cattle.^[13] Thereafter, the family lineage of bison and taurine cattle does not appear to be a straightforward "tree" structure as is often depicted in much evolution, because evidence of interbreeding and crossbreeding is seen between different species and members within this family, even many millions of years after their ancestors separated into different species. This crossbreeding was not sufficient to conflate the different species back together, but it has resulted in unexpected relationships between many members of this group, such as yak being related to American bison, when such relationships would otherwise not be apparent.
A 2003 study of mitochondrial DNA indicated four distinct maternal lineages in tribe Bovini:

1. Taurine cattle and zebu
2. Wisent
3. American bison and yak^[14] and
4. Banteng, gaur, and gayal

However, Y chromosome analysis associated wisent and American bison.^[15] An earlier study using amplified fragment length polymorphism fingerprinting showed a close association of wisent with American bison, and probably with the yak, but noted that the interbreeding of Bovini species made determining relationships problematic.^[16]
The steppe bison (B. priscus) diverged from the lineage that led to cattle (Bos taurus) about 2 to 5 million years ago. The Bison genus is clearly in the fossil record by 2 million years ago.^[17] The steppe bison spread across Eurasia and was the bison pictured in the ancient cave drawings of Spain and Southern France.
The European bison or wisent arose from the steppe bison. Without fossil evidence of other ancestral species between the steppe bison and the European bison, though the European bison might have arisen from the lineage that led to American bison if that lineage backcrossed with the steppe bison. Again, the web of relationships is confusing, but some evidence shows that the European bison is descended from bison that had migrated from Asia to North America, and then back to Europe, where they crossbred with existing steppe bison.^[17]
At one point, some steppe bison crossbred with the ancestors of the modern yak. After that crossbreeding, a population of steppe bison crossed the Bering Land Bridge to North America. Evidence exists of multiple crossings of bison to and from Asia starting before 500,000 years ago and continuing until at least 220,000 years ago^{[citation needed]}. The steppe bison spread through the northern parts of North America and lived in Eurasia until around 11,000 years ago^[18] and North America until 4,000 to 8,000 years ago.^[17]

Skulls of European bison (left) and American bison (right)

Bison latifrons (the "giant" or "longhorn" bison) is thought to have evolved in midcontinent North America from B. priscus, after the steppe bison crossed into North America.^[19][20][21] Giant bison (B. latifrons) appeared in the fossil record about 500,000 years ago.^[17] B. latifrons was one of many species of North American megafauna that became extinct during the transition from the Pleistocene to the Holocene epoch (an event referred to as the Quaternary extinction event). It is thought to have disappeared some 21,000–30,000 years ago, during the late Wisconsin glaciation.^[22]
B. latifrons co-existed with the slightly smaller B. antiquus, which appeared in the North American fossil record around 250,000 years ago.^[23] B. latifrons is believed to have been a more woodland-dwelling, non-herding species, while B. antiquus was a herding grassland-dweller, very much like its descendant B. b. bison.^[24] B. antiquus gave rise to both B. occidentalis (B. antiquus occidentalis), and later B. bison, the modern American bison, some 5,000 to 10,000 years ago.^[25][26] B. antiquus was the most common megafaunal species on the North American continent during much of the Late Pleistocene and is the most common large animal found at the La Brea Tar Pits.^[27]
During the population bottleneck, after the great slaughter of American bison during the 19th century, the number of bison remaining alive in North America declined to as low as 541. During that period, a handful of ranchers gathered remnants of the existing herds to save the species from extinction. These ranchers bred some of the bison with cattle in an effort to produce "cattleo"^[28] (today called "beefalo") Accidental crossings were also known to occur. Generally, male domestic bulls were crossed with buffalo cows, producing offspring of which only the females were fertile. The crossbred animals did not demonstrate any form of hybrid vigor, so the practice was abandoned. Wisent-American bison hybrids were briefly experimented with in Germany (and found to be fully fertile) and a herd of such animals is maintained in Russia. A herd of cattle-wisent crossbreeds (zubron) is maintained in Poland. First-generation crosses do not occur naturally, requiring caesarean delivery. First-generation males are infertile. The U.S. National Bison Association has adopted a code of ethics that prohibits its members from deliberately crossbreeding bison with any other species. In the United States, many ranchers are now using DNA testing to cull the residual cattle genetics from their bison herds. The proportion of cattle DNA that has been measured in introgressed individuals and bison herds today is typically quite low, ranging from 0.56 to 1.8%.^[28][29]
There are also remnant purebred American bison herds on public lands in North America. Three herds are in Yellowstone National Park, Wind Cave National Park in South Dakota and Elk Island National Park in Alberta, Canada. In 2015 a fourth purebred herd of 350 individuals was identified on public lands in the Henry Mountains of southern Utah via genetic testing of mitochondrial and nuclear DNA.^[30] This study, published in 2015, also showed the Henry Mountains bison herd to be free of brucellosis, a bacterial disease that was imported with non-native domestic cattle to North America.^[31]