American bison
| American bison | |
|---|---|
| |
| Scientific classification | |
| Kingdom Information | |
| Domain | Eukaryota |
| Kingdom | Animalia |
| Subkingdom | Bilateria |
| Branch | Deuterostomia |
| Phylum Information | |
| Phylum | Chordata |
| Sub-phylum | Vertebrata |
| Infraphylum | Gnathostomata |
| Class Information | |
| Class | Mammalia |
| Sub-class | Theriiformes |
| Infra-class | Holotheria |
| Order Information | |
| Superorder | Preptotheria |
| Order | Artiodactyla |
| Family Information | |
| Family | Bovidae |
| Sub-family | Bovinae |
| Genus Information | |
| Genus | Bison |
| Species Information | |
| Species | B. bison |
| Subspecies | B. b. athabascae B. b. bison |
| Population statistics | |
| Population | 30,000+ (total est.) 11,248-13,123 (wild est.; 2017) |
| Conservation status | Near threatened[1] |
The American bison is a species of wild cattle of the family Bovidae, and the largest living terrestrial animal in North America. At one time bison herds roamed the plains and valleys from western Canada down to Mexico, serving an important part of Native American survival; bison population was estimated to be around 30 million animals before the arrival of European settlers in North America. Excessive hunting - done in part to control Native Americans - led to a massive decline where they were once on the brink of extinction by the turn of the 20th century. Today, the total number of wild animals is estimated at more than 30,000 individuals. The species is classified as "near threatened" because of its dependence on protective measures and the small size of individual herd populations.
In May 2016, President Barack Obama signed the National Bison Legacy Act,[2] which makes the American Bison next to the bald eagle the national animal of the United States of America.[3]
Description
The bison has a thick coat of dark brown hair, which is almost black in winter. The longest hairs covers the head, forelegs, humps and shoulders, while the hair on the flanks and buttocks is much shorter. With age, the hair on the hump and shoulders begins to lighten, and this lighter coat color is particularly pronounced in older bulls. At the beginning of spring the winter hair sheds, leaving clumps of older fur about the animal which can last until August. Calves have a light reddish coat at birth, which turns brownish-black within their first three months of life. After five to six months, the coat color of the calves is similar to that of their parents.
Bisons have a sexual dimorphism, with mature bulls weighing up to 1,900 pounds; cows are only about half as heavy, weighing between 700 and 1,200 pounds. Calves weigh between 30 and 70 pounds at birth, while a one-year-old bison of both sexes can be between 500 and 700 pounds. The shoulder height in male bison is about 5.4 to 6.1 feet, while that of females is between 4.9 and 5.1 feet. Both sexes bear horns, but that of bulls appear larger and more robust. In addition, the dark coat is longer in male animals on the forehead, neck and forelegs.
Subspecies
- Bison bison athabascae, Wood bison; Canada: northern Alberta and Manitoba, Northwest Territories, Yukon, British Columbia.
- Bison bison bison, Plains bison; grasslands west of Mississippi River to Rocky Mountains, from northern Mexico north to central Alberta, Canada.
Both subspecies are largely similar in physical characteristics, but with the following minor differences:
- The hair on the head, around the horns, in the abdominal area, as well as that of the throat meat is much shorter and less dense on the wood bison than on the plains bison.
- The long hairs on the front end of the plains bison is lighter in color than that of the wood bison.
- The tail of the wood bison is usually longer and hairier than the plains bison.
- The highest point of the hump on the wood bison is forward of the shoulder blades; that of the plains bison is directly above them.
