Wild bison

Wild bison
The American bison (Bison bison), also commonly known as the American buffalo, is a North American species of bison that once roamed the grasslands of North America in massive herds. American Buffalo, It is believed that buffalo, or bison, crossed over a land bridge that once connected the Asian and North American continents.
Bison are now raised for meat and hides. The majority of bison in the world are being raised for human consumption. Bison meat is lower in fat and cholesterol than beef.
Bison are among the most dangerous animals encountered by visitors to the various U.S. and Canadian national parks, and will attack humans if provoked.
Range and habitat
Bison once roamed across much of North America. Today bison are ecologically extinct throughout most of their historic range, except for a few national parks and other small wildlife areas.
Yellowstone National Park has the largest population of free-roaming plains bison (about 4,000), and Wood Buffalo National Park has the largest population of free-roaming wood bison (about 10,000).
The centuries buffalo slowly moved southward, eventually reaching as far south as Mexico and as far east as the Atlantic Coast, extending south to Florida. But the largest herds were found on the plains and prairies from the Rocky Mountains east to the Mississippi River, and from Great Slave Lake in Canada to Texas.
Physical characteristics
A bison has a shaggy, long, dark brown winter coat, and a lighter weight, lighter brown summer coat. As is typical in ungulates, the male bison are slightly larger than the female. Plains Bison are often in the smaller range of sizes, and Wood Bison in the larger range.
Head-and-body length ranges from 210-350 cm (83-138 in) long, the tail adding 50-60 cm (20-24 in). Shoulder height in the species can range from 152 to 186 cm (60-74 in). Typical weigh can range from 318 to 1000 kg.
Subspecies
There are two living subspecies of wild bison in North America
The plains bison Bison bison bison
Two hundred years ago, the plains bison was by far the more common of the two subspecies. It was the dominant grazing animal of the interior plains of the continent, and it often occurred in large herds. A smaller population occurred east of the Mississippi.
There are  few plains bison. A herd of about 600 is fenced in at Elk Island National Park.There are small numbers at Prince Albert National Park in Saskatchewan, Riding Mountain National Park in Manitoba, and Waterton Lakes National Park in Alberta. There are at least 25 herds of plains bison in national and state parks and wildlife refuges in the United States. There are more private collections and on a large number of commercial ranches in both Canada and the United States.
The wood bison Bison bison athabascae.
The wood bison has always lived to the north of its prairie cousin. In historic times its range was centered in northern Alberta and the adjacent parts of British Columbia, the Northwest Territories, and Saskatchewan. Herds made use of aspen parkland, the eastern slopes of the Rocky Mountains, the lowlands of the Peace and Slave rivers, and the coniferous forests and wetland meadows of the upper Mackenzie Valley.
Feeding and diet
Bison are herbivores, grazing on the grasses and sedges of the North American prairies. Their daily schedule involves two-hour periods of grazing, resting and cud chewing, then moving to a new location to graze again.
Reproduction
Bison mate in August and September; gestation is 285 days. A single reddish-brown calf nurses until the next calf is born. If the cow is not pregnant, a calf will nurse for 18 months. Bison cows are mature enough to produce a calf at 3 years of age. Bison bulls may try to mate with cows at 3 years of age, but if more mature bulls are present, they may not be able to compete until they reach 5 years of age.
Predatory
wolves are a major predator of bison. Wolf predation typically peaks in late spring and early summer, with attacks usually being concentrated on cows and calves.
Life expectancy
Bison have a life expectancy of approximately 15 years in the wild and up to 25 years in captivity.