American Bison
Facts
Also known as: American Buffalo
Conservation Status: Near Threatened
Location: North America
Lifespan: Up to 25 years
Also known as: American Buffalo
Conservation Status: Near Threatened
Location: North America
Lifespan: Up to 25 years
Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Bovinae
Genus: Bison
Species: B. bison
Binomial name: Bison bison
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Bovinae
Genus: Bison
Species: B. bison
Binomial name: Bison bison
Description
Head and body length: 210 to 350 cm (83 to 138 in)
Tail: 50 to 60 cm (20 to 24 in)
Shoulder Height: 152 to 186 cm (60 to 74 in)
Weight: 318 to 1000 kg (700 to 1200 lb)
Other: 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. The heads and forequarters are massive, and both sexes have short, curved horns that can grow up to 2 feet (61 cm) long, which they use in fighting for status within the herd and for defense.
Head and body length: 210 to 350 cm (83 to 138 in)
Tail: 50 to 60 cm (20 to 24 in)
Shoulder Height: 152 to 186 cm (60 to 74 in)
Weight: 318 to 1000 kg (700 to 1200 lb)
Other: 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. The heads and forequarters are massive, and both sexes have short, curved horns that can grow up to 2 feet (61 cm) long, which they use in fighting for status within the herd and for defense.
Behaviour
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. Bison are migratory and herd migrations can be directional as well as altitudinal in some areas. Bison have usual daily movements between foraging sites during the summer. In a montane valley, bison have been recorded traveling, on average, 3.2 km a day. The summer ranges of bison appear to be influenced by seasonal vegetation changes, interspersion and size of foraging sites, the rut and the number of biting insects. The size of preserve and availability of water may also be a factor. During fall and winter, bison tend to gather in more wooded areas. During this time, bison partake in horning behaviors. They will rub their horns against trees, young saplings and even telephone poles. Aromatic trees like cedars and pine seem to be preferred. Horning appears to be associated with insect defense as it occurs most often in the fall when the insect population is at its highest. Cedar and pines emit an aroma after bison horn them and this seems to be used as a deterrent for insects. Female bison live in maternal herds which include other females and their offspring. Male offspring leave their maternal herd when around three years old and will either live alone or join other males in bachelor herds. Male and female herds usually do not mingle until the breeding season. However female herds may also contain a few older males. A bison wallow is a shallow depression in the soil, which is used either wet or dry. Bison roll in these depressions, covering themselves with dust or mud. Past explanations and current hypotheses suggested for wallowing behavior include grooming behavior associated with shedding, male-male interaction (typically rutting behavior), social behavior for group cohesion, play behavior, relief from skin irritation due to biting insects; reduction of ectoparasite (tick and lice) load; and thermoregulation.
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. Bison are migratory and herd migrations can be directional as well as altitudinal in some areas. Bison have usual daily movements between foraging sites during the summer. In a montane valley, bison have been recorded traveling, on average, 3.2 km a day. The summer ranges of bison appear to be influenced by seasonal vegetation changes, interspersion and size of foraging sites, the rut and the number of biting insects. The size of preserve and availability of water may also be a factor. During fall and winter, bison tend to gather in more wooded areas. During this time, bison partake in horning behaviors. They will rub their horns against trees, young saplings and even telephone poles. Aromatic trees like cedars and pine seem to be preferred. Horning appears to be associated with insect defense as it occurs most often in the fall when the insect population is at its highest. Cedar and pines emit an aroma after bison horn them and this seems to be used as a deterrent for insects. Female bison live in maternal herds which include other females and their offspring. Male offspring leave their maternal herd when around three years old and will either live alone or join other males in bachelor herds. Male and female herds usually do not mingle until the breeding season. However female herds may also contain a few older males. A bison wallow is a shallow depression in the soil, which is used either wet or dry. Bison roll in these depressions, covering themselves with dust or mud. Past explanations and current hypotheses suggested for wallowing behavior include grooming behavior associated with shedding, male-male interaction (typically rutting behavior), social behavior for group cohesion, play behavior, relief from skin irritation due to biting insects; reduction of ectoparasite (tick and lice) load; and thermoregulation.
Predators or Prey?
In some areas, 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. Observations have shown that wolves actively target herds with calves over ones with none.
In some areas, 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. Observations have shown that wolves actively target herds with calves over ones with none.
Diet
The American bison is a grazer. Its diet is made up of mostly grasses and sedges. It will occasionally eat berries and lichen. In winter, the bison uses its head and hooves to move snow off the vegetation.
The American bison is a grazer. Its diet is made up of mostly grasses and sedges. It will occasionally eat berries and lichen. In winter, the bison uses its head and hooves to move snow off the vegetation.
Habitat
The American bison live on plains, prairies and river valleys.
The American bison live on plains, prairies and river valleys.
Conservation
The American Bison Society, with Roosevelt as its honorary president, was founded in 1905. It was one of United States’ first environmental organizations, and helped trigger a broader environmental movement that resulted in creation of the U.S. National Park System. In 1908, Roosevelt signed a law creating the National Bison Range in Montana. The act set aside rangeland to provide a protected habitat within which wild buffalo herds could be re-established. A wild herd comprising 21 bison was settled in Wyoming in Yellowstone National Park. That herd, now numbering more than 4,000, is the largest group of free-range bison in the United States.
The American Bison Society, with Roosevelt as its honorary president, was founded in 1905. It was one of United States’ first environmental organizations, and helped trigger a broader environmental movement that resulted in creation of the U.S. National Park System. In 1908, Roosevelt signed a law creating the National Bison Range in Montana. The act set aside rangeland to provide a protected habitat within which wild buffalo herds could be re-established. A wild herd comprising 21 bison was settled in Wyoming in Yellowstone National Park. That herd, now numbering more than 4,000, is the largest group of free-range bison in the United States.
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.
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.
